Adverse drug reactions related to the use of fluoroquinolone antimicrobials: an analysis of spontaneous reports and fluoroquinolone consumption data from three italian regions

Toxic Epidermal Necrolysis Observed in a Patient With the HLA-B*1502 Treated With Levofloxacin

PURPOSE

To determine the relationship between HLA-B gene mutations and levofloxacin-induced toxic epidermal necrolysis (TEN).

METHODS

A 71-year-old Chinese woman developed TEN after oral administration of solifenacin (5 mg) and levofloxacin (0.5 g) for cystitis. HLA-B*5801 and HLA-B*1502 alleles were detected using real-time PCR.

FINDINGS

After supportive therapy (antiallergic treatments, plasma exchange, etc) and withdrawal of the culprit medication levofloxacin, the patient was discharged with re-epithelialization of the exfoliated skin. The patient was HLA-B*1502 allele positive and HLA-B*5801 allele negative.

IMPLICATIONS

This is the first report of levofloxacin-induced TEN suspected to be caused by mutations in the HLA-B*1502 allele.

Psychiatric disorders associated with fluoroquinolones: a pharmacovigilance analysis of the FDA adverse event reporting system database

Background

Fluoroquinolones are broad-spectrum antibiotics with significant antimicrobial activity. Despite their therapeutic benefits, they are associated with a range of adverse drug reactions (ADRs), particularly those affecting the central nervous system (CNS). This study aimed to analyze the psychiatric ADRs linked to fluoroquinolones using data from the FDA Adverse Event Reporting System (FAERS) database.

Methods

A retrospective pharmacovigilance study was conducted using FAERS data from Q1 2004 to Q4 2023. The data processing phase involved the FDA-recommended deduplication method, and ADRs were classified according to Medical Dictionary for Regulatory Activities (MedDRA). Disproportionality analysis was performed using the reporting odds ratio (ROR), and statistical significance was assessed using the Chi-square test or Fisher's exact test.

Results

The study identified 84,777 reports associated with fluoroquinolones, with 359,480 Preferred Terms-annotated entries, 27,816 of these reports were psychiatric ADRs. Mood disorders were the most frequently reported, including anxiety, depression, and delirium, with some reports escalating to suicidal ideation and behaviors. The Standardized MedDRA Query classification system was used to categorize these ADRs into Depression, Suicide/self-injury, Psychosis and psychotic disorders, and Non-infectious encephalopathy/delirium. Ciprofloxacin was most frequently linked to depression and suicidal ideation, while moxifloxacin showed a robust correlation with delirium. The risk of psychiatric ADRs varied by age group, with affective disorders more prevalent in adults under 65 and psychosis and delirium in those over 65.

Conclusion

Fluoroquinolones are associated with a range of psychiatric ADRs, with notable differences between the drugs in the class. The study highlights the need for caution in prescribing fluoroquinolones, particularly for patients with pre-existing mental health conditions or those in higher risk age groups. The findings also underscore the importance of considering age-specific preventive strategies when administering these antibiotics.

The phenomenon of phototoxicity and long-term risks of commonly prescribed and structurally diverse drugs

Photosensitivity to structurally diverse drugs is a common but under-reported adverse cutaneous reaction and can be classified as phototoxic or photoallergic. Phototoxic reactions occur when the skin is exposed to sunlight after administering topical or systemic medications that exhibit photosensitizing activity. These reactions depend on the dose of medication, degree of exposure to ultraviolet light, type of ultraviolet light, and sufficient skin distribution volume. Accurate prediction of the incidence and phototoxic response severity is challenging due to a paucity of literature, suggesting that phototoxicity may be more frequent than reported. This paper reports an extensive literature review on phototoxic drugs; the review employed pre-determined search criteria that included meta-analyses, systematic reviews, literature reviews, and case reports freely available in full text. Additional reports were identified from reference sections that contributed to the understanding of phototoxicity. The following drugs and/or drug classes are discussed: amiodarone, voriconazole, chlorpromazine, doxycycline, fluoroquinolones, hydrochlorothiazide, nonsteroidal anti-inflammatory drugs, and vemurafenib. In reviewing phototoxic skin reactions, this review highlights drug molecular structures, their reactive pathways, and, as there is a growing association between photosensitizing drugs and the increasing incidence of skin cancer, the consequential long-term implications of photocarcinogenesis.

Evaluation of healthcare professionals' understanding of fluoroquinolones' safety profile, usage, and boxed warnings in Pakistan

INTRODUCTION

Fluoroquinolones (FQs) is a distinct class of antibiotics which are prescribed and used quite frequently worldwide, despite the box warnings (BW) issued by Food and Drug Administration (FDA). Literature has shown in spite of BWs related to FQs there is minimal impact on health care professionals (HCPs) prescribing habits, potentially attributing towards limited and insufficient awareness. In Pakistan, FQs are mostly prescribed antibiotics for microbial treatments, therefore the purpose of this study was to determine the level of knowledge about the safety profile, use, and BW of FQs among HCPs working in Pakistan.

METHODS

A cross-sectional study was undertaken among the HCPs of Khyber Pakhtunkhwa province of Pakistan from October 2022 to December 2022. A validated questionnaire was used to assess the knowledge of HCPs regarding FQs, its safety profile and BW. A random convenient sample technique was used while recruiting HCPs in this study. As the HCPs comprised physicians, dentists, pharmacist and nurses, all were approached in person and the study objective was fully elaborated and explained to them. The statistic test like: one-way ANOVA, independent-t test, multivariate logistic regression were used keeping the p-value < 0.05 as statistically significant.

RESULTS

A total of n = 250 HCPs were approached, of which n = 186 HCPs completed the questionnaire with a response rate of 74.4%. FQs prescribing pattern was only assessed among the prescribers, i.e., physicians and dentists (39/186). The mean knowledge score for indications was 5.29 ± 3.05, while for the adverse effects was 7.70 ± 2.61. The highest score for knowledge for indications and adverse effect score was achieved by physicians followed by dentist. The mean knowledge score for the BW was 3.46 ± 2.93 and among the HCPs for the BW of FQs, 20.4% of the HCPs had appropriate knowledge score (score ≥ 50%). The knowledge score was significantly higher in males (p = 0.039), dentists (p = 0.001), HCPs having master/specialization level of education (p = 0.003), HCPs working in government sector hospitals (p = 0.010) and secondary care hospitals (p = 0.001) while the multivariate logistic regression analysis showed that HCPs working in primary care hospital (OR: 6.2) and secondary care hospital (OR: 20.3) were associated with the tendency to achieve 50% or above knowledge score.

CONCLUSION

 Findings of this study reveals the unsatisfactory knowledge of HCPs regarding the safety profile, use, and BW of FQs putting patients at heightened risks of FQs associated AEs. Therefore, it is crucial to implement a national antimicrobial stewardship program, seminars and lectures aimed at continuously updating the knowledge of HCPs, regardless of their specialties, and effectively restrict the misuse of antimicrobial and disseminate FDA BWs in clinical practice.

Assessment of Knowledge Regarding Safety Profile, Use, and Boxed Warnings of Fluoroquinolones Among Healthcare Professionals in Saudi Arabia: A Potential Implication for Drug Regulatory Authorities

Background

Despite a series of "boxed warnings" (BWs) issued by the US Food and Drug Administration (FDA), fluoroquinolones (FQs) are among the most prescribed antibiotics across the world. Moreover, few studies demonstrated that BW of FQs had less or no impact on prescribing patterns among healthcare professionals (HCPs), which might be attributed to the lack of knowledge toward such warnings. Since FQs contribute to a major proportion of antimicrobial prescriptions in the Kingdom of Saudi Arabia (KSA), this study aimed to ascertain the extent of knowledge toward safety profile, use, and BW of FQs among HCPs working in the KSA.

Methods

This cross-sectional study (May-August 2021) was conducted among HCPs working in KSA through a validated questionnaire. The HCPs were requested to identify the indications, adverse effects (AEs), and BW of FQs. The knowledge score (out of 40) was estimated among participants, and its association with demographics was ascertained through the chi-square test, Student's t-test, or Mann-Whitney U-test and one-way ANOVA, or Kruskal-Wallis test, where appropriate.

Results

Of the 573 participants (age: 36.1 ± 10.6 years, men: 59.7%), 262 (45.8%) were prescribers reporting frequent use of ciprofloxacin, levofloxacin, and ofloxacin. One-fourth (25.6%) of the prescribers did not recognize nalidixic acid as an agent from FQs class. About 60% of participants correctly identified the mechanism of action of FQs. The average knowledge score was 14.8 ± 6.4, where only 21.5% of respondents scored ≥50%. The average knowledge score for indications, AEs, and BW domains was 5.29 ± 3.05, 6.17 ± 4.05, and 2.3 ± 1.5, respectively. Only 75 (13.1%) participants recognized half of the BW, and 38.6% of participants identified at least one warning. The HCPs aged >40 years (p = 0.043), having non-Saudi's nationality (p < 0.001), working in Riyadh and Eastern regions (p < 0.001), having pharmacy and medicine disciplines (p < 0.001), practicing in public sectors (p = 0.004), and having more than 10 years of experience (p < 0.001) were significantly associated with high knowledge score.

Conclusion

This study demonstrates the unsatisfactory knowledge toward safety profile, use, and BW of FQs among HCPs which may put patients at increased risks of AEs. The knowledge score differed among various socio-demographic groups. There is a dire need to initiate the antimicrobial-focused educational campaigns among HCPs regardless of their specialties and methods to improve education and disseminate FDA warnings in practice.

A VigiBase Descriptive Study of Fluoroquinolone-Associated Peripheral Nervous System Disorders

BACKGROUND

Recent drug safety concerns described fluoroquinolone (FQ)-induced peripheral nervous system reactions. The objective of this study was to characterize such reports from VigiBase.

METHODS

The analysis included FQ-induced peripheral nervous system disorder adverse drug reaction (ADR) reports (up to July 2019). We looked into the disproportionality data in terms of proportional reporting ratio (PRR) and information component (IC) values, and descriptive analysis was performed for FQ-ADRs positive associations (ADRs, suspected FQs, potential risk factors, such as associated therapy and underlying disease).

RESULTS

Disproportionality analysis revealed 4374 reports (3531 serious) with peripheral nervous system ADRs associated with at least three FQs (neuropathy peripheral, 5492; neuralgia, 481; polyneuropathy, 220; sensory loss, 99; peripheral sensorimotor neuropathy, 39). Among these, both time-to-onset and duration of reaction were mostly between 1-7 days and ≥30 days. Most of the ADRs were not recovered/resolved at the time of reporting.

CONCLUSION

The results augment the existing data on FQ safety concerns, specifically their potential effect on the nervous system.

Are Fluoroquinolones or Macrolides Better for Treating Legionella Pneumonia? A Systematic Review and Meta-analysis

BACKGROUND

The Infectious Diseases Society of America recommends either a fluoroquinolone or a macrolide as a first-line antibiotic treatment for Legionella pneumonia, but it is unclear which antibiotic leads to optimal clinical outcomes. We compared the effectiveness of fluoroquinolone versus macrolide monotherapy in Legionella pneumonia using a systematic review and meta-analysis.

METHODS

We conducted a systematic search of literature in PubMed, Cochrane, Scopus, and Web of Science from inception to 1 June 2019. Randomized controlled trials and observational studies comparing macrolide with fluoroquinolone monotherapy using clinical outcomes in patients with Legionella pneumonia were included. Twenty-one publications out of an initial 2073 unique records met the selection criteria. Following PRISMA guidelines, 2 reviewers participated in data extraction. The primary outcome was mortality. Secondary outcomes included clinical cure, time to apyrexia, length of hospital stay (LOS), and the occurrence of complications. The review and meta-analysis was registered with PROSPERO (CRD42019132901).

RESULTS

Twenty-one publications with 3525 patients met inclusion criteria. The mean age of the population was 60.9 years and 67.2% were men. The mortality rate for patients treated with fluoroquinolones was 6.9% (104/1512) compared with 7.4% (133/1790) among those treated with macrolides. The pooled odds ratio assessing risk of mortality for patients treated with fluoroquinolones versus macrolides was 0.94 (95% confidence interval, .71-1.25, I2 = 0%, P = .661). Clinical cure, time to apyrexia, LOS, and the occurrence of complications did not differ for patients treated with fluoroquinolones versus macrolides.

CONCLUSIONS

We found no difference in the effectiveness of fluoroquinolones versus macrolides in reducing mortality among patients with Legionella pneumonia.

Molecular and Biochemical Basis of Fluoroquinolones-Induced Phototoxicity-The Study of Antioxidant System in Human Melanocytes Exposed to UV-A Radiation

Phototoxicity of fluoroquinolones is connected with oxidative stress induction. Lomefloxacin (8-halogenated derivative) is considered the most phototoxic fluoroquinolone and moxifloxacin (8-methoxy derivative) the least. Melanin pigment may protect cells from oxidative damage. On the other hand, fluoroquinolone–melanin binding may lead to accumulation of drugs and increase their toxicity to skin. The study aimed to examine the antioxidant defense system status in normal melanocytes treated with lomefloxacin and moxifloxacin and exposed to UV-A radiation. The obtained results demonstrated that UV-A radiation enhanced only the lomefloxacin-induced cytotoxic effect in tested cells. It was found that fluoroquinolones alone and with UV-A radiation decreased superoxide dismutase (SOD) activity and SOD1 expression. UV-A radiation enhanced the impact of moxifloxacin on hydrogen peroxide-scavenging enzymes. In turn, lomefloxacin alone increased the activity and the expression of catalase (CAT) and glutathione peroxidase (GPx), whereas UV-A radiation significantly modified the effects of drugs on these enzymes. Taken together, both analyzed fluoroquinolones induced oxidative stress in melanocytes, however, the molecular and biochemical studies indicated the miscellaneous mechanisms for the tested drugs. The variability in phototoxic potential between lomefloxacin and moxifloxacin may result from different effects on the antioxidant enzymes.

Quinolones-Induced Musculoskeletal, Neurological, and Psychiatric ADRs: A Pharmacovigilance Study Based on Data From the Italian Spontaneous Reporting System

Background

The use of quinolones has been associated with the development of serious and persistent adverse drug reaction (ADR) mainly affecting muscles, joints and the nervous system. This risk has led the European Medicines Agency (EMA) to endorse some restrictions on the use of this class of antibiotic. Therefore, we performed a study to primary estimate the reporting probability of musculoskeletal, neurological, and psychiatric ADRs among quinolone generations using national data.

Methods

We retrieved Individual Case Safety Reports (ICSRs) with a quinolone as suspected drug among those reported through the Campania spontaneous reporting system from January 1^st, 2001 to April 30^th 2019. Moreover, we retrieved national aggregated safety data from the online public report system (RAM system) for the period from January 1^st, 2002 to March 31^st, 2019. Risk factors were classified as “age greater than 60 years,” “therapeutic indication,” “renal failure,” “organ transplantation,” “use of corticosteroid,” and “history of side effects”. Reporting odds ratio (ROR) was computed to evaluate the reporting probability of musculoskeletal, neurological, or psychiatric events among quinolones generations.

Results

A total of 87 ICSRs with a quinolone as suspected drug that reported at least one musculoskeletal, neurological, and psychiatric adverse event were identified in the Campania spontaneous reporting system. Forty-nine (56.3%) ICSRs reported risk factors (total risk factors 59). The most reported risk factor was “age greater than 60 years” (69.5%), followed by “therapeutic indication” (16.9%), “renal failure” (5.1%), “organ transplantation” (3.4%), “use of corticosteroid” (3.4%), and “history of side effects” (1.7%). Second-generation quinolones were associated with a lower reporting probability of musculoskeletal (ROR 0.70; 95% CI 0.63–0.79), neurological (ROR 0.81; 95% CI 0.73–0.90), and psychiatric (ROR 0.55; 95% CI 0.44–0.63) ADRs compared to the third generation of quinolones.

Conclusions

Our findings showed that third-generation quinolones were always associated with a higher reporting probability of musculoskeletal, neurological, and psychiatric ADRs compared to the second generation ones. Moreover, we described risk factors in more than half of our cases suggesting that the inappropriate use of quinolones is a phenomenon that may frequently predispose patients to the occurrence of these ADRs.

The safety of antimicrobials for the treatment of community-acquired pneumonia

Introduction: Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide, and its prevalence continues to increase. Despite the efficacy of antimicrobials, their safety and tolerability remain topics of interest and concern for clinicians and patients alike.Areas covered: This review outlines the main antimicrobial classes recommended for the empirical treatment of CAP in current guidelines, together with a potential new class. Each pharmacological group underwent a safety evaluation based on all available data about drug-related toxicities. The authors also present their mechanisms of action, their pharmacokinetic and pharmacodynamic properties, and the main clinical studies.Expert opinion: Overall, antimicrobials currently marketed for the treatment of CAP are well tolerated and generally safe. However, unusual and sometimes serious adverse effects can occur in susceptible populations. Attention should be paid to identifying patients at risk of developing drug-related toxicities because, although most effects are transient, some could be disabling, permanent, or even fatal. Post-marketing surveillance remains crucial for gathering data to overcome the limitations of preclinical and clinical studies in estimating the true prevalence of drug-related adverse events.

High Incidence of New-Onset Joint Pain in Patients on Fluoroquinolones as Antituberculous Treatment

BACKGROUND

Joint pain is frequently observed in patients on antituberculous treatment, and pyrazinamide is known to be associated with joint pain in patients receiving antituberculous treatment. Fluoroquinolone-associated joint pain and tendon injury have been reported in long-term corticosteroid and transplant recipients, but data are lacking in patients with tuberculosis.

OBJECTIVES

The objective of this study was to examine the incidence of joint pain manifested during administration of antituberculous therapy and their association with fluoroquinolones.

METHODS

Patients diagnosed with tuberculosis attending the outpatient clinic over a period of 1 year were reviewed and divided into 3 groups: group A receiving pyrazinamide, group B receiving a fluoroquinolone, and group C receiving both pyrazinamide and a fluoroquinolone. Latency to onset of joint pain was noted in all 3 groups. Joint pain was initially managed with analgesics, and associated hyperuricemia was treated with allopurinol/febuxostat. Causative drugs were stopped in case of intolerable joint pain.

RESULTS

260 patients (47% females, aged 38 ± 18 years; mean ± SD) were included [group A (n = 140), group B (n = 81), and group C (n = 39)]. Overall, 76/260 (29%) patients developed joint pain: group A - 24/140 patients (17%), group B - 32/81 patients (40%), and group C - 20/39 patients (51%). The median latency to the onset of joint pain was 83 days (interquartile range, IQR 40-167): 55 days (IQR 32-66) in group A, 138 days (IQR 74-278) in group B, and 88 days (IQR 34-183) in group C. Hyperuricemia was present in 12/24 (50%) patients in group A and 11/20 (55%) patients in group C. Pyrazinamide was stopped in 7/140 (5%) patients in group A, fluoroquinolones in 6/81 (7%) patients in group B, and both pyrazinamide and fluoroquinolones were stopped in 5/39 (13%) patients in group C because of intolerable joint pain. Major joints affected were knees and ankles.

CONCLUSION

There is a high incidence of joint pain in patients receiving antituberculous treatment, which is higher when fluoroquinolones or the pyrazinamide-fluoroquinolone combination are administered as compared to pyrazinamide alone.

Adverse Effects of Fluoroquinolones: A Retrospective Cohort Study in a South Indian Tertiary Healthcare Facility

The Food and Drug Administration (FDA) safety review revealed that the use of fluoroquinolones (FQs) is linked with disabling and potentially permanent serious adverse effects. These adverse effects compromise the tendons, muscles, joints, nerves, and central nervous system of the human body. The purpose of the study was to investigate the incidence and risk factors for adverse drug reactions (ADRs) caused by FQs in comparison with other antibiotics used. A retrospective cohort study was conducted over seven months in Kasturba Medical College Hospital, Manipal, India. Patients who were prescribed with FQs were selected as the study cohort (SC; n = 482), and those without FQs were the reference cohort (RC; n = 318). The results showed that 8.5% (41) of patients developed ADRs in the SC, whereas 4.1% (13) of patients developed ADRs in the RC. With oral and parenteral routes of administration, almost a similar number of ADRs were observed. Levofloxacin caused the highest number of ADRs reported, especially with the 750-mg dose. Based on a multiple logistic regression model, FQ use (odds ratio (OR): 2.27; 95% confidence interval (CI): 1.18-4.39; p = 0.015) and concomitant steroid use (OR: 3.19; 95% CI: 1.31-7.79; p = 0.011) were identified as independent risk factors for the development of ADRs among antibiotics users, whereas age was found to be protective (OR: 0.98; 95% CI: 0.97-1.00; p = 0.047). The study found a higher incidence of ADRs related to FQs compared to other antibiotics. The study concludes a harmful association between FQ use and the development of ADRs. Moreover, FQs are not safe compared to other antibiotics. Hence, the use of FQs should be limited to the conditions where no other alternatives are available.

Quinolone Allergy

Quinolones are the second most common antibiotic class associated with drug-induced allergic reactions, but data on quinolone allergy are scarce. This review article discusses the available evidence on quinolone allergy, including prevalence, risk factors, diagnosis, clinical manifestations, cross-reactivity, and management of allergic reactions. Although the incidence of quinolone allergy is still lower than beta-lactams, it has been increasingly reported in recent decades, most likely from its expanded use and the introduction of moxifloxacin. Thorough patient history remains essential in the evaluation of quinolone allergy. Many diagnostic tools have been investigated, but skin tests can yield false-positive results and in vitro tests have not been validated. The drug provocation test is considered the test of choice to confirm a quinolone allergy but is not without risk. Evidence regarding cross-reactivity among the quinolones is limited and conflicting. Quinolone allergy can be manifested either as an immediate or delayed reaction, but is not uniform across the class, with moxifloxacin posing the highest risk of anaphylaxis. Quinolone should be discontinued when an allergic reaction occurs and avoided in future scenarios, but desensitization may be warranted if no alternatives are available.

Drug and chemical induced photosensitivity from a clinical perspective

Drug photosensitivity is a relatively common occurrence and a range of mechanisms may be involved. Some of these mechanisms will be discussed, including the most common, that of drug phototoxicity. Different types of photosensitivity are addressed with respect to clinical presentation, mechanisms and additionally the contribution to our understanding through clinically directed investigations and regulatory requirements. Repeated controlled therapeutic use of drug phototoxicity, with psoralen-UVA (PUVA) photochemotherapy and photodynamic therapy (PDT) will also be discussed. Finally, the potential for drug-induced photocarcinogenesis will also be covered.

Mass chemoprophylaxis for control of outbreaks of meningococcal disease

Although vaccination is the main strategy used to control meningococcal disease outbreaks, mass chemoprophylaxis has also been used as an immediate response to outbreaks, either to supplement vaccination or when vaccination is not possible. However, public health guidelines regarding the use of mass chemoprophylaxis for outbreak control vary by country, partly because the impact of mass chemoprophylaxis on the course of an individual outbreak is difficult to assess. We have reviewed data for the use of mass chemoprophylaxis during 33 outbreaks that occurred both in military populations and in communities and non-military organisations. In most outbreaks, no additional cases of meningococcal disease occurred after mass chemoprophylaxis, or cases occurred only in individuals who had not received prophylaxis. A delay of several weeks was common before cases occurred among prophylaxis recipients. Overall, the outbreak reports that we reviewed suggest that mass chemoprophylaxis might provide temporary protection to chemoprophylaxis recipients during outbreaks.

The Relative Risk of Achilles Tendon Injury in Patients Taking Quinolones

OBJECTIVE

To examine the association between quinolone use and Achilles tendon injury, comparing well-matched cohorts of users of quinolone and nonquinolone antibiotics, and well-matched cohorts of quinolone users and patients not using any nonquinolone antibiotics.

PATIENTS AND METHODS

This retrospective cohort study used Clinformatics data from 2008-2014. Using the propensity score, we matched quinolone users with other antibiotic users and quinolone users with nonusers. The primary outcome was Achilles tendon injury within 6 months. Bivariate analyses determined risk factors for Achilles tendon injury, and conditional logistic regression assessed the impact of quinolone use on these injuries.

RESULTS

A total of 716,522 fluoroquinolone users were matched with other antibiotic users, and 645,034 fluoroquinolone users were matched with nonusers. Rates of Achilles tendon injury were less than 0.5% in all groups. Quinolone use increased the risk of Achilles tendon injury compared with other antibiotic users (odds ratio [OR] 1.24, 95% confidence interval [CI] 1.17-1.31) and nonusers (OR 1.54, 95% CI 1.44-1.64). Interaction with age did not significantly impact the relationship between quinolone use and Achilles injury; however, older quinolone users had a slightly higher relative risk of injury than nonusers versus younger patients. Furthermore, the youngest group of patients had similarly elevated relative risk for injury with quinolone use as did the elderly.

CONCLUSION

Although quinolone use increases the risk of Achilles tendon injury, the absolute risk increase is minimal, especially when compared with similar morbidity patients taking other nonquinolone antibiotics. In relatively healthy populations, such as the one studied here, quinolone use may not make a clinically significant contribution to risk of Achilles tendon injury, at any age range, among those in need of such drugs.

National Estimates of Emergency Department Visits for Antibiotic Adverse Events Among Adults-United States, 2011-2015

BACKGROUND

Detailed, nationally representative data describing high-risk populations and circumstances involved in antibiotic adverse events (AEs) can inform approaches to prevention.

OBJECTIVE

Describe US burden, rates, and characteristics of emergency department (ED) visits by adults for antibiotic AEs.

DESIGN

Nationally representative, public health surveillance of adverse drug events (National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance [NEISS-CADES]) and a nationally projected database of dispensed prescriptions (QuintilesIMS), 2011-2015.

PATIENTS

Antibiotic-treated adults (≥ 20 years) seeking ED care.

MAIN MEASURES

Estimated annual numbers and rates of ED visits for antibiotic AEs among outpatients treated with systemically administered antibiotics.

KEY RESULTS

Based on 10,225 cases, US adults aged ≥ 20 years made an estimated 145,490 (95% confidence interval, 115,279-175,701) ED visits for antibiotic AEs each year in 2011-2015. Antibiotics were implicated in 13.7% (12.3-15.2%) of all estimated adult ED visits for adverse drug events. Most (56.6%; 54.8-58.4%) antibiotic AE visits involved adults aged < 50 years, and 71.8% (70.4-73.1%) involved females. Accounting for prescriptions dispensed from retail and long-term care pharmacies, adults aged 20-34 years had twice the estimated rate of ED visits for oral antibiotic AEs compared with those aged ≥ 65 years (9.7 [7.6-11.8] versus 4.6 [3.6-5.7] visits per 10,000 dispensed prescriptions, respectively). Allergic reactions accounted for three quarters (74.3%; 70.0-78.6%) of estimated ED visits for antibiotic AEs. The three most frequently implicated antibiotic classes in ED visits for antibiotic AEs were oral sulfonamides (23.2%; 20.6-25.8%), penicillins (20.8%; 19.3-22.4%), and quinolones (15.7%; 14.2-17.1%). Per-prescription rates declined with increasing age group.

CONCLUSIONS

Antibiotics are a common cause of ED visits by adults for adverse drug events and represent an important safety issue. Quantifying risks of AEs from specific antibiotics for specific patient populations, such as younger adults, provides additional information to help clinicians assess risks versus benefits when making the decision to prescribe or not prescribe an antibiotic. AE rates may also facilitate communication with patients about antibiotic risks.

Fluoroquinolone Use and Risk of Carpal Tunnel Syndrome: A Pharmacoepidemiologic Study

Fluoroquinolone-induced peripheral neuropathies and tendinopathies are well documented, but there are no epidemiologic studies on the risk of carpal tunnel syndrome (CTS). We conducted a case-control study of >6 million patients. Fluoroquinolone use is associated with increased risk of CTS (rate ratio, 1.34 [95% confidence interval, 1.31-1.37]).

Natural extracellular nanovesicles and photodynamic molecules: is there a future for drug delivery?

Photodynamic molecules represent an alternative approach for cancer therapy for their property (i) to be photo-reactive; (ii) to be not-toxic for target cells in absence of light; (iii) to accumulate specifically into tumour tissues; (iv) to be activable by a light beam only at the tumour site and (v) to exert cytotoxic activity against tumour cells. However, to date their clinical use is limited by the side effects elicited by systemic administration. Extracellular vesicles are endogenous nanosized-carriers that have been recently introduced as a natural delivery system for therapeutic molecules. We have recently shown the ability of human exosomes to deliver photodynamic molecules. Therefore, this review focussed on extracellular vesicles as a novel strategy for the delivery of photodynamic molecules at cancer sites. This completely new approach may enhance the delivery and decrease the toxicity of photodynamic molecules, therefore, represent the future for photodynamic therapy for cancer treatment.

Adverse reactions to fluoroquinolones in the Nigerian population: an audit of reports submitted to the National Pharmacovigilance Centre from 2004 to 2016

Adverse drug reactions (ADRs) recorded in national pharmacovigilance databases in developed countries have been analyzed. However, adverse reactions to fluoroquinolones were observed globally despite their wide use and safety concerns. We provided information on the pattern of adverse reactions to fluoroquinolones reported spontaneously to the National Pharmacovigilance Centre (NPC), Nigeria. ADRs to fluoroquinolones reported to the NPC, over a period of 12 years, were analyzed. Evaluation was done for annual reports, age and gender of patients, type of reporter, suspected fluoroquinolones and adverse reactions, onset and outcome of ADRs, and causality. A total of 18527 ADR reports were received by the NPC. Antibiotics accounted for 1371(7.4%) of the total reports and fluoroquinolones accounted for 256 (18.7%) cases. A total of 540 ADRs due to fluoroquinolones was experienced by the patients. Multiple ADRs were experienced by 165 (65%) patients. Norfloxacin (2; 0.8%), moxifloxacin (3; 1.2%), ofloxacin (10; 3.9%), ciprofloxacin (112; 43.8%), and levofloxacin (129; 50.4%) were responsible for the ADRs. Neurological disorders (121; 22.4%), gastrointestinal disorders (118; 21.9%), and skin‐appendage disorders (116; 21.5%) were the most reported ADRs, while pruritus (41; 7.6%), abdominal pain (34; 6.3%), vomiting (34; 6.3%), and skin rash (27; 5.0%) were the most frequently reported specific ADRs. Thirty‐four (6.4%) patients experienced serious ADRs. Fluoroquinolones accounted for a small but significant proportion of ADRs spontaneously reported to the NPC in Nigeria. Ciprofloxacin and levofloxacin were the two most culpable fluoroquinolones due to their inappropriate use or increased use in multi‐drug resistant tuberculosis (MDR‐TB) treatment.

Tendon Injury and Fluoroquinolone Use: A Systematic Review

BACKGROUND

Fluoroquinolone antibiotics are commonly used to treat infections and are prescribed by general practitioners, medical specialists and surgeons. Tendon injury has been associated with the use of these medications but the risk associated with newer fluoroquinolones has not been established.

OBJECTIVES

The aim of this systematic review was to evaluate the evidence from observational studies to determine the strength of the association between fluoroquinolone use and tendinopathy, and to identify risk factors for this complication.

METHODS

We searched MEDLINE, EMBASE and the Cochrane Collaboration from inception through May 2013 to identify observational studies focused on tendon injury and fluoroquinolones. Studies with original data were selected for inclusion following the PRISMA guidelines. Of the 560 abstracts screened, 16 relevant studies were independently rated by three authors (WW, AS, DC) using the Newcastle-Ottawa Quality Assessment Scale, and assigned a quality score out of 9. High-quality studies (i.e. scored 4.5 or higher) are summarized in detail in this article. Data were independently extracted by two authors (WW, AS).

RESULTS

Overall, 16 studies were included in our study. Eight were deemed to be of high quality and five specifically evaluated Achilles tendon rupture. In addition, three studies examined Achilles tendinitis, and three included tendon disorders (including any tendon rupture) as an outcome. Results from these studies suggest that individuals exposed to fluoroquinolones are at increased risk for Achilles tendon rupture, particularly within the first month following exposure to the drug (odds ratios ranged from 1.1 to 7.1). One study showed an increased risk of tendon rupture in those over 60 years of age. Five studies stated that individuals taking fluoroquinolones and oral corticosteroids are at increased risk for tendon injury compared with those taking fluoroquinolones alone. Four studies examined the differential effect of a limited number of fluoroquinolones. Ofloxacin had the highest risk of tendon injury in three of the studies.

LIMITATIONS

Included studies are observational in nature and rely on self-report, which may lead to misclassification or underestimation of tendon injury.

CONCLUSIONS

Observational studies showed an increased risk of tendon injury, including tendon rupture and tendinitis, with exposure to fluoroquinolone antibiotic therapy. Although this complication appears to be rare, concomitant corticosteroids increase the risk for tendon injury, which varies depending on the fluoroquinolone used.

Effect of fluoroquinolones on melanogenesis in normal human melanocytes HEMn-DP: a comparative in vitro study

PURPOSE

Fluoroquinolones are one of the most commonly prescribed classes of antibiotics. However, their use is often connected with high risk of phototoxic reactions that lead to various skin or eye disorders. The aim of this study was to examine the effect of ciprofloxacin, lomefloxacin, moxifloxacin and fluoroquinolone derivatives with different phototoxic potential, on the viability and melanogenesis in melanocytes.

MATERIALS AND METHODS

Normal human epidermal melanocytes, dark pigmented (HEMn-DP) were used as an in vitro model system. The effect of the tested antibiotics on cell viability and melanization in pigmented cells was investigated using a spectrophotometric method. The WST-1 assay was used to detect the cytotoxic effect of antibiotics.

RESULTS

Ciprofloxacin, lomefloxacin and moxifloxacin induced the concentration-dependent loss in melanocytes viability. The values of EC₅₀ for the tested fluoroquinolone derivatives were found to be 2.0 mM for ciprofloxacin, 0.51 mM for lomefloxacin and 0.27 mM for moxifloxacin. The exposure of cells to different concentrations of the analyzed drugs resulted in decrease in melanin content and tyrosinase activity. The highest decrease was observed for lomefloxacin which may explain its high phototoxic potential in vivo. The role of melanin in the mechanism of the toxicity of fluoroquinolones was discussed and the obtained results were compared with the previously obtained data concerning light-pigmented melanocytes (HEMa-LP).

CONCLUSIONS

The results obtained in vitro suggest that the phototoxic potential of fluoroquinolones in vivo depends on specific drug-melanin interaction, the ability of drugs to affect melanogenesis as well as on the degree of melanocytes pigmentation.

Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis--A Comprehensive Review and Guide to Therapy. I. Systemic Disease

The intent of this review is to comprehensively appraise the state of the art with regard to Stevens Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), with particular attention to the ocular surface complications and their management. SJS and TEN represent two ends of a spectrum of immune-mediated, dermatobullous disease, characterized in the acute phase by a febrile illness followed by skin and mucous membrane necrosis and detachment. The widespread keratinocyte death seen in SJS/TEN is rapid and irreversible, and even with early and aggressive intervention, morbidity is severe and mortality not uncommon. We have divided this review into two parts. Part I summarizes the epidemiology and immunopathogenesis of SJS/TEN and discusses systemic therapy and its possible benefits. We hope this review will help the ophthalmologist better understand the mechanisms of disease in SJS/TEN and enhance their care of patients with this complex and often debilitating disease. Part II (April 2016 issue) will focus on ophthalmic manifestations.

Fluoroquinolone-induced serious, persistent, multisymptom adverse effects

We present a case series of four previously healthy, employed adults without significant prior medical history in each of whom symptoms developed while on fluoroquinolones (FQs), with progression that continued following discontinuation evolving to a severe, disabling multisymptom profile variably involving tendinopathy, muscle weakness, peripheral neuropathy, autonomic dysfunction, sleep disorder, cognitive dysfunction and psychiatric disturbance. Physicians and patients should be alert to the potential for FQ-induced severe disabling multisymptom pathology that may persist and progress following FQ use. Known induction by FQs of delayed mitochondrial toxicity provides a compatible mechanism, with symptom profiles (and documented mechanisms of FQ toxicity) compatible with the hypothesis of an exposure-induced mitochondrial neurogastrointestinal encephalomyopathy.

Ofloxacin Induced Cutaneous Reactions in Children

Cutaneous adverse effects to antimicrobials are a major health problem. Though majority of them are mild and self-limiting, severe variants like Steven Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN) are not uncommon. Ofloxacin, a fluoroquinolone widely used for the treatment of urinary tract infections, acute bacterial diarrheas, enteric fever, STDs and other soft tissue infections either as a single drug or in combination with other drugs. Earlier a case of mucocutaneous maculopapular rash with oral ofloxacin and was reported in an adult. In the present hospital set up there were few reports of such reactions to adults. Here we report three different variants of reactions associated with oral ofloxacin in chlidren. Early detection of cutaneous lesions and immediate withdrawal of the offending drug can prevent progression of such reactions to their severe variants as well as morbidity and mortality.

Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN): could retinoids play a causative role?

Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) are overlapping manifestations on a spectrum of acute drug-induced conditions associated with severe blistering, skin peeling, and multi-organ damage. TEN is an eruption resembling severe scalding, with ≥30% skin detachment. SJS is a mild form of TEN, characterized histologically by epidermal keratinocyte apoptosis with dermo-epidermal separation and extensive small blisters with <10% body surface skin detachment. The syndrome can be induced by numerous medications and typically occurs 1–4 weeks after the initiation of therapy. Granulysin is found in the lesions of patients with SJS/TEN and plays a significant pathogenic role in the condition, but the overall mechanisms linking medications, granulysin, and disease manifestations remain obscure. This paper reviews evidence suggesting that the different medications implicated in SJS/TEN have the common property of interacting and synergizing with endogenous retinoids (vitamin A and its congeners), in many instances causing the latter to accumulate in and damage the liver, the main storage organ for vitamin A. It is hypothesized that liver damage leads to the spillage of toxic retinoid compounds into the circulation, resulting in an endogenous form of hypervitaminosis A and cytotoxicity with widespread apoptosis, mediated by granulysin and recognized as SJS/TEN. Subject to testing, the model suggests that symptom worsening could be arrested at onset by lowering the concentration of circulating retinoids and/or granulysin via phlebotomy or plasmapheresis or by pharmacological measures to limit their expression.

Effect of norfloxacin and moxifloxacin on melanin synthesis and antioxidant enzymes activity in normal human melanocytes

Fluoroquinolone antibiotics provide broad-spectrum coverage for a number of infectious diseases, including respiratory as well as urinary tract infections. One of the important adverse effects of these drugs is phototoxicity which introduces a serious limitation to their use. To gain insight the molecular mechanisms underlying the fluoroquinolones-induced phototoxic side effects, the impact of two fluoroquinolone derivatives with different phototoxic potential, norfloxacin and moxifloxacin, on melanogenesis and antioxidant enzymes activity in normal human melanocytes HEMa-LP was determined. Both drugs induced concentration-dependent loss in melanocytes viability. The value of EC50 for these drugs was found to be 0.5 mM. Norfloxacin and moxifloxacin suppressed melanin biosynthesis; antibiotics were shown to inhibit cellular tyrosinase activity and to reduce melanin content in melanocytes. When comparing the both analyzed fluoroquinolones, it was observed that norfloxacin possesses greater inhibitory effect on tyrosinase activity in melanocytes than moxifloxacin. The extent of oxidative stress in cells was assessed by measuring the activity of antioxidant enzymes: SOD, CAT, and GPx. It was observed that norfloxacin caused higher depletion of antioxidant status in melanocytes when compared with moxifloxacin. The obtained results give a new insight into the mechanisms of fluoroquinolones toxicity directed to pigmented tissues. Moreover, the presented differences in modulation of biochemical processes in melanocytes may be an explanation for various phototoxic activities of the analyzed fluoroquinolone derivatives in vivo.

Determination of the Potential of Drug Candidates to Cause Severe Skin Disorders Using Computational Modeling

Efficient and accurate prediction for drugs' potential to cause rare and severe adverse drug reactions (ADRs) is needed to facilitate the evaluation of risk-benefit ratio of drug candidates during drug development. Severe skin disorders like the Stevens Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), which are life-threatening dermatological conditions, are such ADRs that have not received sufficient attention so far. In this study, a total of 1127 marketed drugs were screened for their potential to cause SJS/TEN, of which 255 were found to cause SJS/TEN and 239 were unlikely to cause SJS/TEN. One-class classification method was used to develop multiple prediction models. An applicability domain was determined to define the applicability of the model. Ensemble method was used to develop ensemble models to improve prediction ability. The final ensemble model achieved a sensitivity and specificity of 81 % and 67.4 %, respectively, when estimated using the external 5-fold cross validation method, and a sensitivity of 66.7 % when assessed using an external positive set. The results suggest the methods used in this study are potentially useful for facilitating the prediction of rare and severe ADRs.

Toxic epidermal necrolysis and Stevens-Johnson syndrome in South Africa: a 3-year prospective study

BACKGROUND

Toxic Epidermal Necrolysis (TEN) and Stevens-Johnson syndrome (SJS) remain feared medication-related reactions. HIV infection and tuberculosis predispose to drug eruptions, yet there is a paucity of data on TEN/SJS in populations with high prevalences of both diseases.

AIM

The aim of this prospective observational study was to describe the features and outcomes of patients admitted with TEN/SJS at a large academic hospital in South Africa. We aimed to identify poor prognostic indicators and to validate the use of the TEN-specific severity-of-illness score (SCORTEN) in this population.

METHODS

All patients admitted with TEN/SJS over a 3-year period were enrolled. Disease severity was graded according to percentage skin involved and SCORTEN. Co-morbid diagnoses, clinical features, investigations, complications and outcomes were noted.

RESULTS

75 patients (39.9 ± 10.6 years, 16 males, 59 HIV positive) were classified as TEN (n  = 42), TEN/SJS overlap (n = 11) and SJS (n = 22). Twenty-four percent died, most from refractory septic shock. Non-survivors had a higher mean SCORTEN on Days 1 and 3 (1.89 vs. 1.04, P = 0.006 and 2.27 vs. 0.90, P < 0.001). A SCORTEN ≥2 on Days 1 and 3 predicted non-survival (OR = 2.94, P = 0.047; OR = 7.45, P < 0.001). Other predictors of non-survival included HIV infection (OR = 6.01, P = 0.058), HIV-tuberculosis co-infection (OR = 8.5, P < 0.001), ≥40% skin involvement (OR = 20.27, P < 0.001), anaemia (OR = 4.68, P = 0.005), hypoalbuminemia (OR = 8.5, P = 0.001) and severe sepsis (OR = 71.09, P < 0.001).

CONCLUSION

Most patients with TEN/SJS were HIV positive and female. We validated the use of SCORTEN and identified several prognostic indicators, most significant being HIV-tuberculosis co-infection, ≥40% skin involvement and severe sepsis.

Effects of systemic ornidazole, systemic and local compound ornidazole and pefloxacin mesylate on experimental periodontitis in rats

Background

The purpose of the current study is to evaluate the effects of systemic ornidazole (SO) and systemic and local compound ornidazole and pefloxacin mesylate (SCOPM/LCOMP) on the inflammatory response associated with rat experimental chronic periodontitis (ECP) in sites with subgingival debridement.

Material/Methods

Periodontitis was induced in male Sprague-Dawley rats by placing a thin steel ligature around the upper first molars and inoculating them with Porphyromonas gingivalis 381. After the successful induction of the rat ECP, the periodontitis rats were randomly divided into 3 different combined treatment groups: (A) SO with scaling and root planing (SRP); (B) SCOMP with SRP; and (C) LCOMP with SRP. After 2 weeks the effects of the treatments were evaluated based on gingivitis, plaque index, probing pocket depth, aspartate aminotransferase, alveolar bone loss, and hematoxylin-eosin staining of the region around the first molars.

Results

After treatment, comparison with ECP was performed. The mean percentage reductions of SBI in SO, SCOPM, and LCOPM were 27.73%, 33.61%, and 58.82%, respectively. Those of PI were 33.20%, 42.80%, and 60.00%; those of PPD were 48.66%, 55.70%, and 72.48%; those of GCF-AST were 41.64%, 49.03%, and 66.42%; and those of ABL were 41.19%, 43.63%, and 54.47%, respectively. The inflammatory score of H&E showed median scores of 2.5, 1.75, 1.63, and 0.95 for ECP, SO, SCOMP, and LCOMP, respectively. All 3 treatment groups exhibited significantly reduced inflammation indicators (P<0.05). Of the 3, group C was the most effective (P<0.05).

Conclusions

Although all the combined treatment groups responded to therapy with significant resolution of the infection, adjunctive LCOMP therapy is more effective for periodontitis.

Quinolones: review of psychiatric and neurological adverse reactions

Quinolones are a class of antibacterial agents for the treatment of several infectious diseases (e.g. urinary and respiratory tract infections). They are used worldwide due to their broad spectrum of activity, high bioavailability and good safety profile. The safety profile varies from quinolone to quinolone. The aim of this article was to review the neurological and psychiatric adverse drug reaction (ADR) profile of quinolones, using a literature search strategy designed to identify case reports and case series. A literature search using PubMed/MEDLINE (from inception to 31 October 2010) was performed to identify case reports and case series related to quinolone-associated neurological and psychiatric ADRs. The search was conducted in two phases: the first phase was the literature search and in the second phase relevant articles were identified through review of the references of the selected articles. Relevant articles were defined as articles referring to adverse events/reactions associated with the use of any quinolone. Abstracts referring to animal studies, clinical trials and observational studies were excluded. Identified case reports were analysed by age group, sex, active substances, dosage, concomitant medication, ambulatory or hospital-based event and seriousness, after Medical Dictionary for Regulatory Activities (MedDRA®) coding. From a total of 828 articles, 83 were identified as referring to nervous system and/or psychiatric disorders induced by quinolones. 145 individual case reports were extracted from the 83 articles. 40.7% of the individual case reports belonged to psychiatric disorders only, whereas 46.9% related to neurological disorders only. Eight (5.5%) individual case reports presented both neurological and psychiatric ADRs. Ciprofloxacin, ofloxacin and pefloxacin were the quinolones with more neurological and psychiatric ADRs reported in the literature. Ciprofloxacin has been extensively used worldwide, which may explain the higher number of reports, while for ofloxacin and pefloxacin, the number of reports may be over-representative. A total of 232 ADRs were identified from the selected articles, with 206 of these related to psychiatric and/or neurological ADRs. The other 26 were related to other body systems but were reported together with the reactions of interest. Mania, insomnia, acute psychosis and delirium were the most frequently reported psychiatric adverse events; grand mal convulsion, confusional state, convulsions and myoclonus were the most frequently reported neurological adverse events. Several aspects should be taken into account in the development of CNS adverse effects, such as the pharmacokinetics of quinolones, chemical structure and quinolone uptake in the brain. These events may affect not only susceptible patients but also 'healthy' patients.

Cardiovascular and metabolic safety profiles of the fluoroquinolones

INTRODUCTION

Certain fluoroquinolones share similar indications of use. A comparison among Cardiovascular and metabolic (i.e., dysglycemia) safety profiles of the fluoroquinolones might be particularly useful for the prescribers' decision-making process as well as to hypothesize future researcher purposes.

AREAS COVERED

A literature search was conducted using keywords apt to identify information on safety profile of the fluoroquinolones. Publications concerned with descriptive and etiological surveys were manually reviewed.

EXPERT OPINION

Cardiac alterations and blood glucose impairments might be associated with any fluoroquinolone. However, the benefit/risk profile of these agents could be stratified for the single compounds. Several predisposing factors, such as diabetes, heart illnesses and their related pharmacotherapies, might exacerbate the risk of potentially serious adverse events. In this context, the opportunity of the more appropriate choice among different fluoroquinolones could be applicable.

Identifying adverse drug reactions associated with drug-drug interactions: data mining of a spontaneous reporting database in Italy

BACKGROUND

Drug-drug interactions (DDIs) are an important cause of adverse drug reactions (ADRs). Many studies have recently considered this issue, but most of them focus only on potential interactions and are often related to the hospital setting. A spontaneous reporting database could be a valuable resource for detection of ADRs associated with DDIs; however, data in the literature are limited.

OBJECTIVE

To detect those patients treated with potentially interacting drugs and the cases where reported adverse reactions are a possible consequence of DDIs, using an Italian spontaneous reporting database.

METHODS

The data were obtained from a database containing all reports of suspected ADRs from five Italian regions (January 1990 to December 2007) that are the main contributors to the Italian spontaneous reporting system. All reports containing at least two drugs, reported as being suspected of causing the ADR or as concomitant medication, were selected and a list of drug pairs was drawn up. We performed a search to verify which drug pairs are considered a potential DDI, using the Internet version of the DRUGDEX(R) system. For each report containing a potential DDI, we verified whether the description of the adverse reaction corresponded to the interaction effect.

RESULTS

The database contained 45 315 reports, of which 17 700 (39.1%) had at least two reported drugs. We identified 5345 (30.2%) reports with potential DDIs, and in 1159 (21.7%) of these reports a related ADR was reported. The percentage of reports with potential DDIs increased in relation to the number of concomitantly administered drugs, ranging from 9.8% for two drugs to 88.3% for eight or more drugs. The percentages of serious or fatal reports of ADRs associated with a DDI were significantly higher than other reports analysed. The mean age, percentage of male patients and the mean number of drugs were also significantly higher in reports with DDIs than in other reports. In 235 of 1159 reports (20.3%), both interacting drugs were recognized as suspect by the reporter. This percentage varies in relation to the drugs involved, ranging from 2% to about 65%. The most frequently reported interaction was digoxin and diuretics, but no fatal ADRs were reported with this combination. The combination of anticoagulant and antiplatelet agents was responsible for the greatest number of serious reactions and deaths.

CONCLUSIONS

This study validates that spontaneous reporting, despite its limitations, can be an important resource for detecting ADRs associated with the concomitant use of interacting drugs. Moreover, our data confirm that DDIs could be a real problem in clinical practice, showing that more than one in five patients exposed to a potential DDI experienced a related ADR.

Fluoroquinolones in community-acquired pneumonia: guide to selection and appropriate use

Fluoroquinolone use has dramatically increased since the introduction of the first respiratory fluoroquinolone in the late 1990s. Over a relatively brief period of time, the respiratory fluoroquinolones have supplanted other first-line options as the predominant community-acquired pneumonia (CAP) therapy in hospitals. This article discusses the rise of the fluoroquinolone era, debates the comparative effectiveness of fluoroquinolones for CAP therapy, examines fluoroquinolone resistance and adverse drug reactions, and discusses new trends in pneumonia epidemiology and outcomes assessment. Overall, published data suggest that fluoroquinolone monotherapy is associated with improved patient survival compared with β-lactam monotherapy and similar survival to β-lactam plus macrolide combination therapy. Fluoroquinolone monotherapy may be associated with shorter hospital length of stay compared with β-lactam plus macrolide combination therapy, particularly in severe pneumonia or with high-dose therapy. There is insufficient evidence to conclude that any individual fluoroquinolone therapy is better than another with regards to patient mortality. Fluoroquinolones are generally well tolerated and Streptococcus pneumoniae resistance remains low; however, rare but serious adverse effects have been reported. Some members of the fluoroquinolone class have been removed from the market amidst safety concerns. Pneumonia classifications have changed and antipseudomonal fluoroquinolones may have a role in healthcare-associated pneumonia when administered in combination with other antipseudomonal and anti-methicillin-resistant Staphylococcus aureus therapies.

Practical management of antibiotic allergy in adults

This review looks at the main issues around immediate hypersensitivity and the role and limitations of testing. The majority of literature on antibiotic hypersensitivity relates to β-lactam antibiotics, mainly because of the heavy usage of this class of drugs. Concerns around cross-reactivity always worry clinicians, particularly in the emergency situation. Reasonable data now exist in relation to β-lactam antibiotics and derivatives, which enable appropriate risk management to be undertaken. The available literature for other classes of antibiotics is also discussed.

Safety profile of the fluoroquinolones: analysis of adverse drug reactions in relation to prescription data using four regional pharmacovigilance databases in Italy

BACKGROUND

Fluoroquinolones are widely used both in primary care and in hospital settings. Since the last comparison performed in Italy on the safety profiles of different fluoroquinolones, a new molecule, prulifloxacin, has been introduced into the market and several warnings concerning this class of drugs have been released. The aim of this study was to reassess the safety profiles of fluoroquinolones using the database of the Italian Interregional Group of Pharmacovigilance (IGP) and the administrative data of fluoroquinolone prescriptions.

METHODS

All adverse drug reactions (ADRs) reported in four Italian regions (Lombardy, Veneto, Emilia Romagna and Tuscany) were retrieved from the IGP database. Consumption data (defined daily dose [DDD]/1000 inhabitants/day) were used as denominators. Both single reports and all ADRs (classified by System Organ Classes and MedDRA Preferred Term [PT]) due to fluoroquinolones were considered as numerators of each analysis, comparing two periods (2005 vs 2006). All fluoroquinolones with at least ten reports per year were included in the analysis.

RESULTS

On the basis of 272 reports (532 single ADRs or PTs), patients did not show any statistically significant differences between 2005 and 2006 in terms of sex, age and number of concurrent medications. After adjustment for drug consumption, moxifloxacin showed the highest reporting rate (84.6 reports/DDD/1000 inhabitants/day; 15.4 serious reports/DDD/1000 inhabitants/day) followed by prulifloxacin (72.2; 22.2 serious) and levofloxacin (55.3; 30.6 serious) in 2005. An increment of ADR/report rates was observed over the 2 years for all fluoroquinolones except prulifloxacin, which had the lowest ADR reporting rate in 2006 (25.0; 12.5 serious). In 2006, the rate of serious ADRs associated with prulifloxacin was lower than with ciprofloxacin, while in 2005 serious events were almost equal for both compounds (55.6 vs 47.6 serious ADRs/DDD/1000 inhabitants/day). Ciprofloxacin showed the highest proportion of cutaneous PTs (e.g. rash, exanthema). Tendinopathies were mainly due to levofloxacin.

CONCLUSIONS

These data suggest that different fluoroquinolones are characterized by different rates and types of ADRs. Among them, prulifloxacin was associated with more ADRs than other fluoroquinolones in 2005 but with fewer ADRs in 2006, when its consumption increased. Although these findings may represent an encouraging perspective towards a more appropriate use of fluoroquinolones because of their individual safety profiles, further pharmacoepidemiological studies must be performed to substantiate these results.

Safety profile of the fluoroquinolones: focus on levofloxacin

The fluoroquinolone class of antibacterial agents are among the most frequently prescribed drugs, with utility in a broad range of bacterial infections. Although very useful agents, the fluoroquinolones as a class are associated with a number of adverse events, some with considerable clinical significance. In the past 15-20 years, tolerability concerns have led to restrictions on the use of the fluoroquinolones and, in some instances, the withdrawal of agents from the market. This review focuses on the safety and tolerability of levofloxacin, a third-generation fluoroquinolone, relative to other fluoroquinolones. A literature search was performed of the MEDLINE database encompassing the dates 1980-2009, using as keywords the drug names levofloxacin and concurrently marketed fluoroquinolones combined with the words 'safety', 'adverse effect' or 'adverse drug reaction', or the name of the specific adverse effect. Adverse events commonly associated with the fluoroquinolones include gastrointestinal and CNS toxicity (most frequently headache and dizziness), as well as other adverse events including ECG abnormalities (for example QT interval prolongation), disrupted glucose metabolism, phototoxicity, tendon and joint disorders, hypersensitivity and skin disorders, and hepatic toxicity. Package inserts for the fluoroquinolones in Europe and the US contain warnings regarding these risks. US package inserts also carry 'black-box' warnings regarding the risk of tendon rupture and joint disorders with these agents; however, there is a substantial body of evidence to indicate that there are marked differences in the tolerability profiles of the individual agents within the fluoroquinolone class. These differences may be explained, at least in part, by structural differences: all fluoroquinolones share a basic quinolone core, with differences in specific side chains underlying the adverse event relationships. Furthermore, many of the fluoroquinolone-associated adverse effects and toxicities occur more frequently in patients with pre-existing risk factors, or in certain subpopulations. Notably, package inserts for the fluoroquinolones carry warnings regarding use in the elderly, paediatric patients and patients with pre-existing, or factors predisposing to, seizure disorders. Because of this, many adverse reactions with these agents could be prevented by improving patient screening and education. The recent withdrawal of gatifloxacin due to dysglycaemia makes it timely to review the safety and tolerability of the individual agents in this class. Overall, it appears that levofloxacin is relatively well tolerated, with low rates of clinically important adverse events such as CNS toxicity, cardiovascular toxicity and dysglycaemia.

Death caused by toxic epidermal necrolysis (Lyell syndrome)

Toxic epidermal necrolysis (TEN) is characterized by fever, scalded appearance of the skin, and epidermolysis associated to blister formation and exfoliation, and it is caused by hypersensitivity reaction to a drug. The authors report two cases of death as a result of TEN; both referred to old aged women treated with a polytherapy including allopurinol. Both patients displayed erythematous skin lesions similar to scald burns and epidermolysis at the face, chest, and abdomen and died shortly after hospitalization. Autopsy findings and histological examinations revealed epidermal necrolysis and confirmed the clinical diagnosis. A strict time-correlation between allopurinol administration and symptoms was evidenced. Because of its iatrogenic origin, TEN often arises suspicions of medical liability; however, because of its unpredictable nature, the occurrence of this syndrome cannot be ascribed to the medical staff whose main task is the rapid diagnosis and the correct management.

Hepatotoxicity of antibacterials: Pathomechanisms and clinical

Drug-induced hepatotoxicity is a frequent cause of liver disease and acute liver failure, particularly in patients treated with multiple drugs. Several antibacterial drugs have the potential to cause severe liver injury and failure. This article aims to increase the awareness and understanding of drug induced liver injury (DILI) due to antibacterial drugs. It reviews the pattern of antibacterial DILI and provides details on molecular mechanisms and toxicogenomics, as well as clinical data based on epidemiology studies. Certain antibacterial drugs are more frequently linked to hepatotoxicity than others. Therefore, the hepatotoxic potential of tetracyclines,sulfonamides, tuberculostatic agents, macrolides, quinolones,and beta-lactams are discussed in more detail. Efforts to improve the early detection of DILI and the acquisition of high-quality epidemiological data are pivotal for increased patient safety.

Modification of innervation pattern by fluoroquinolone treatment in the rat salivary glands

Fluoroquinolone antibiotics (FQAs) are widely used in dental and medical therapy. Despite their known severe adverse actions on the central and peripheral nervous system, little attention has been directed toward the potential toxic side effects of these compounds on the oral tissues. As the saliva secretion is controlled by the nervous system and neuropeptides, the neurotoxic effect of pefloxacin (PEF), a representative member of FQAs, was studied in rats in the present work. Previously, we demonstrated a significant weight loss of parotid gland tissue, a marked decrease in 3H-thymidine incorporation, a decreased volume of saliva and amylase activity of the glandular tissue in response to PEF. Animals received intraperitoneal injection of PEF (20 mg/100 g body weight daily) for 3 and 7 days. Normal histology, and neurofilament 200, substance P (SP) and calcitonin gene-related polypeptide (CGRP) containing nerve fibers were detected with immunohistochemical methods. A marked decrease of the weights in salivary glands and the acinar diameters were measured. Similarly, a strong and significant decrease of the number of SP and CGRP containing nerve fibers were detected. These findings suggest that the impaired morphology and innervation pattern of salivary glands is related to the neurotoxic adverse effect of FQA treatment.