Fluconazole-induced jaundice

Efficacy of Flavonoids in Combating Fluconazole Resistant Oral Candidiasis

BACKGROUND

Candida is an opportunistic fungus often present in the oral mucosa. In the compromised immune system, it may become pathogenic and cause oral candidiasis. This infection is more common with Candida albicans; though, non-albicans Candida spp also have significant relevance. Current treatment guidelines include polyenes, azoles and echinocandins, where fluconazole is the primary therapeutic option. However, both inherited and acquired resistance to fluconazole is exhaustively reported. The development of resistance has resulted in the worsening of the original and re-emergence of new fungal diseases. Thus, the development of an anti-candidiasis therapy with a satisfactory outcome is the urgent need of the hour.

OBJECTIVE

This review article aims to stimulate the research in establishing the synergistic efficacy of various flavonoids with fluconazole to combat the resistance and develop an effective pharmacotherapy for the treatment of oral candidiasis. Further, in this article, we discuss in detail the mechanisms of action of fluconazole, along with the molecular basis of development of resistance in Candida species.

METHOD

PubMed and other databases were used for literature search.

RESULTS

The designing of natural drugs from the plant- derived phytochemicals are the promising alternates in modern medicine. The challenge today is the development of alternative anti- oral candidiasis drugs with increased efficacy, bioavailability and better outcome which can combat azole resistance. Identifying the flavonoids with potential antifungal action at low concentrations seems to meet the challenges.

CONCLUSION

Phyto-active constituents, either alone or in combination with conventional antibiotics may be an effective approach to deal with global antimicrobial resistance. The efficacy of herbal therapy for decades suggests that bacteria, fungi, and viruses may have a reduced ability to adapt and resistance to these natural antimicrobial regimes.

Pre-Existing Liver Disease and Toxicity of Antifungals

Pre-existing liver disease in patients with invasive fungal infections further complicates their management. Altered pharmacokinetics and tolerance issues of antifungal drugs are important concerns. Adjustment of the dosage of antifungal agents in these cases can be challenging given that current evidence to guide decision-making is limited. This comprehensive review aims to evaluate the existing evidence related to antifungal treatment in individuals with liver dysfunction. This article also provides suggestions for dosage adjustment of antifungal drugs in patients with varying degrees of hepatic impairment, after accounting for established or emerging pharmacokinetic–pharmacodynamic relationships with regard to antifungal drug efficacy in vivo.

Antifungal agents and liver toxicity: a complex interaction

INTRODUCTION

The number of antifungal agents has sharply increased in recent decades. Antifungals differ in their spectrum of activity, pharmacokinetic/pharmacodynamic properties, dosing, safety-profiles and costs. Risk of developing antifungal associated hepatotoxicity is multifactorial and is influenced by pre-existing liver disease, chemical properties of the drug, patient demographics, comorbidities, drug-drug interactions, environmental and genetic factors. Antifungal related liver injury typically manifests as elevations in serum aminotransferase levels, although the clinical significance of these biochemical alterations is not always clear. Incidence rates of hepatotoxicity induced by antifungal therapy range widely, occurring most frequently in patients treated with azole antifungals for documented fungal infections.

AREAS COVERED

This review provides an update regarding the hepatotoxicity profiles of the modern systemic antifungals used in treatment of invasive fungal infections. Expert commentary: Understanding the likelihood and pattern of hepatotoxicity for all suspected drugs can aid the clinician in early detection of liver injury allowing for intervention and potential mitigation of liver damage. Therapeutic drug monitoring is emerging as a potential tool to assess risk for hepatotoxicity.

Looking beyond highly active antiretroviral therapy: drug-related hepatotoxicity in patients with human immunodeficiency virus infection

Management of human immunodeficiency virus (HIV) has become increasingly complex since the introduction of highly active antiretroviral therapy (HAART). Patients with HIV have become exposed to an increasing array of drugs to treat HIV, prevent opportunistic infections and immune dysfunction, and manage comorbid illnesses and therapeutic complications. Hepatic complications have become common and may lead to discontinuation of treatment and significant morbidity. Up to 90% of patients with acquired immunodeficiency syndrome (AIDS) receive at least one drug that can cause hepatotoxicity. Clinicians treating patients with HIV frequently face difficulty distinguishing abnormal liver transaminase levels and toxicities in patients receiving several drugs. Some potential causes of hepatic dysfunction are viral infections, alcohol and substance abuse, and hepatotoxic drugs such as HAART. Recent reports have focused on the hepatotoxicity of HAART and the role of hepatitis viruses to the exclusion of many other agents prescribed for patients with HIV. Many of the common antibiotics, antifungals, antivirals, and ancillary agents prescribed for patients with HIV are independently associated with hepatotoxicity. Clinicians should be aware of the potential non-antiretroviral hepatotoxic agents that are frequently administered in HIV management.

Cardiovascular consequences of sleep-related breathing disorders

Sleep-related breathing disorders (SRBDs) represent a spectrum of abnormalities that range from simple snoring to upper airway resistance syndrome to sleep apnea. The clinical presentation may include obesity, snoring, neuropsychological dysfunction, and daytime hypersomnolence and tiredness. The acute hemodynamic alterations of obstructive sleep apnea include systemic and pulmonary hypertension, increased right and left ventricular afterload, and increased cardiac output. Earlier reports attributed the coexistence of SRBDs with cardiovascular diseases to the shared risk factors such as age, sex, and obesity. However, recent epidemiologic data confirm an independent association between SRBDs and the different manifestations of cardiovascular diseases. Possible mechanisms may include a combination of intermittent hypoxia and hypercapnia, repeated arousals, sustained increase in sympathetic tone, reduced baroreflex sensitivity, increased platelet aggregation, and elevated plasma fibrinogen and homocysteine levels. The strength of the association, its pathogenesis, and the impact of treatment of SRBDs on the health outcome of patients with cardiovascular diseases are issues to be addressed in future studies.

Systemic antifungal therapy

Systemic antifungal therapy for superficial mycoses has advanced greatly since the introduction of griseofulvin in 1958. The discovery of the azole antifungal compounds, ketoconazole, itraconazole, and fluconazole, allowed for a broader spectrum of treatment and a shorter treatment duration. Terbinafine, through a unique mechanism of action, has a fungicidal power not seen previously in the other antifungals. It is important to use our knowledge of the pharmacology in combination with clinical experience and cost of therapy in order to select the proper drug. The search to identify new oral antifungal agents should continue, since none of the five currently used drugs fulfill the criteria of the "ideal" antifungal.

A cohort study on the risk of acute liver injury among users of ketoconazole and other antifungal drugs

AIMS

The aim of this cohort study was to estimate the risk of clinical acute liver injury among users of oral antifungals identified in the general population of the General Practice Research Database in UK.

METHODS

The cohort included 69 830 patients, 20-79 years old, free of liver and systemic disease, who had received at least one prescription for either oral fluconazole, griseofulvin, itraconazole, ketoconazole, or terbinafine between 1991 and 1996.

RESULTS

Sixteen cases of acute liver injury were identified and validated. Ten cases occurred during nonuse of oral antifungals with a background rate of 0.6 per 100,000 person-months (95% confidence interval 0.3,1.1). Five cases occurred during current use of oral antifungals. Two were using ketoconazole, another two itraconazole, and one terbinafine. Incidence rates of acute liver injury were 134.1 per 100 000 person-months (36.8,488.0) for ketoconazole, 10.4 (2.9-38.1) for itraconazole, and 2.5 (0.4,13. 9) for terbinafine. The remaining case was associated with past use of fluconazole. Ketoconazole was the antifungal associated with the highest relative risk, 228.0 (95% confidence interval 33.9,933.0), when compared with the risk among nonusers, followed by itraconazole and terbinafine with relative risks of 17.7 (2.6,72.6) and 4.2 (0.2, 24.9), respectively.

CONCLUSIONS

Ketoconazole and itraconazole were the two oral antifungal associated with a marked increase of clinical acute liver injury. The risk associated with ketoconazole should be taken into account when prescribing it as initial treatment for uncomplicated fungal infections.

Safety and tolerability of fluconazole in children

The safety profile of fluconazole was assessed for 562 children (ages, 0 to 17 years) comprising 323 males and 239 females. The data are derived from 12 clinical studies of fluconazole as prophylaxis or treatment for a variety of fungal infections in predominantly immunocompromised patients. Most children received multiple doses of fluconazole in the range of 1 to 12 mg/kg of body weight; a few received single doses. Administration was mainly by oral suspension or intravenous injection. Overall, 58 (10.3%) children reported 80 treatment-related side effects. The most common side effects were associated with the gastrointestinal tract (7.7%) or skin (1.2%). Self-limiting, treatment-related side effects affecting the liver and biliary system were reported in three patients (0.5%). Overall, 18 patients (3.2%) discontinued treatment due to side effects, mainly gastrointestinal symptoms. Dose and age did not appear to influence the incidence and pattern of side effects. Treatment-related laboratory abnormalities were uncommon, the most frequent being transient elevated alanine aminotransferase (4.9%), aspartate aminotransferase (2.7%), and alkaline phosphatase (2.3%) levels. Although 98.6% of patients were taking concomitant medications, no clinical or laboratory interactions were observed. The safety profile of fluconazole was compared with those of other antifungal agents, mostly oral polyenes, by using a subset of data from five controlled studies. Side effects were reported by more patients treated with fluconazole (45 of 382; 11.8%) than by those patients treated with comparable agents (25 of 381; 6.6%); vomiting and diarrhea were the most common events in both groups. The incidence and type of treatment-related laboratory abnormalities were similar for the two groups. In conclusion, fluconazole was well tolerated by the pediatric population, many of whom were suffering from severe underlying disease and were taking a variety of concurrent medications. The safety profile of fluconazole in children mirrors the excellent safety profile seen in adults.

Oropharyngeal candidiasis in immunocompromised children: a randomized, multicenter study of orally administered fluconazole suspension versus nystatin. The Multicenter Fluconazole Study Group

OBJECTIVE

To compare the efficacy, safety, and tolerance of fluconazole suspension versus nystatin in the treatment of oropharyngeal thrush in immunocompromised children.

DESIGN

Multicenter, randomized, observer-masked trial.

SETTING

Thirty-two centers participated, including hospitals and ambulatory care clinics.

PATIENTS

We enrolled 182 immunocompromised infants and children, ages 5 months to 14 years, with signs of oral thrush and presence of yeasts on potassium hydroxide- or gram-stained preparations. Subjects were randomly assigned to receive a single daily dose of fluconazole suspension, 2 to 3 mg/kg per day, or nystatin, 400,000 units four times daily for 14 days; 159 patients, who had culture confirmation of thrush and received at least 7 days of study drug, were evaluated for efficacy; all patients were evaluated for safety.

RESULTS

Clinical cure was demonstrated in 91% of the subjects in the fluconazole group and 51% of the subjects in the nystatin group (p < 0.001), and eradication of the organism cultured at entry occurred in 76% and 11% (p < 0.001), respectively. Gastrointestinal conditions developed in six patients who received fluconazole and in three who received nystatin; two fluconazole recipients were subsequently withdrawn from the study. Laboratory abnormalities occurred with equal frequency in both groups. Clinical relapse rates were similar in both groups at 2 weeks (18% and 24% for fluconazole and nystatin, respectively) and 1 month (28% and 27%, respectively) after the completion of study drug.

CONCLUSIONS

Fluconazole suspension is more effective than nystatin in the treatment of thrush in immunocompromised children. Both regimens were well tolerated.

Fluconazole. An update of its antimicrobial activity, pharmacokinetic properties, and therapeutic use in vaginal candidiasis

Fluconazole is a bis-triazole antifungal drug which has a pharmacokinetic profile characterised by its high water solubility, low affinity for plasma proteins, and metabolic stability. After a single 150 mg oral dose, therapeutic concentrations in vaginal secretions are rapidly achieved and are sustained for a duration sufficient to produce high clinical and mycological responses in nonimmunocompromised patients with vaginal candidiasis (candidosis). At this dosage, clinical and mycological responses have compared favourably with responses achieved after multiple dose regimens of other oral and intravaginal antifungal agents. Clinical efficacy rates have ranged between 92 and 99% at short term evaluation (5 days post-treatment). At 80 to 100 days post-treatment clinical efficacy rates of 91% have been reported. In addition, limited data indicate that fluconazole is more effective than placebo as prophylactic treatment of frequently recurring vaginal candidiasis. Single oral doses of fluconazole 150 mg are well tolerated. Most frequently observed adverse events are gastrointestinal symptoms, which are generally mild and transient in nature. Thus, fluconazole is a valuable alternative to established systemic and intravaginal azole antifungal drugs which are used to treat vaginal candidiasis. Moreover, in view of its favourable patient acceptability and compliance profile compared with alternative treatments, single-dose oral fluconazole should be considered as a first-line therapeutic choice for the treatment of women with vaginal candidiasis.

Worsening of liver function with fluconazole and review of azole antifungal hepatotoxicity

OBJECTIVE

To report a case of fluconazole worsening of liver dysfunction.

CASE SUMMARY

A patient with hepatitis experienced worsening of her liver function when treated with fluconazole for a Candida infection in her urine. Elevations in aspartate aminotransferase, alanine aminotransferase, and total bilirubin concentrations along with increased prothrombin time and activated partial thromboplastin time were noted as early as the second day of therapy. After discontinuation of the fluconazole, the liver parameters returned to their normal baseline level.

DISCUSSION

Hepatotoxicity associated with azole antifungal therapy is reviewed. This patient experienced elevations in liver function enzymes; the literature relating to this topic is evaluated.

CONCLUSIONS

It is probable that fluconazole therapy was involved in the worsening of this patient's liver function. Liver function should be monitored during the course of fluconazole therapy in patients with underlying liver dysfunction. It appears from the published reports that HIV-positive patients may be at risk for hepatotoxicity with fluconazole.

Candida and oral candidosis: a review

Candida species are the most common fungal pathogens isolated from the oral cavity. Their oral existence both as a commensal and an opportunist pathogen has intrigued clinicians and scientists for many decades, and recent investigations have revealed many attributes of this fungus contributing to its pathogenicity. In addition, the advent of the human immunodeficiency virus infection and AIDS has resulted in a resurgence of oral Candida infections. Clinicians are witnessing not only classic forms of the diseases but also newer clinical variants such as erythematous candidosis, rarely described hithertofore. Therefore, this review is an attempt at detailing the current knowledge on Candida and oral candidoses together with the newer therapeutic regimes employed in treating these mycoses.

Fluconazole. Review and situation among antifungal drugs in the treatment of opportunistic mycoses of human immuno-deficiency virus infections

Fluconazole is a novel triazole antifungal drug chiefly used in the treatment of opportunistic mycoses in immuno-compromised patients, particularly those with the acquired immuno-deficiency syndrome (AIDS). In comparison with other antifungal drugs, fluconazole has outstanding physical and pharmacokinetic properties, such as an excellent aqueous solubility allowing a parenteral formulation, high bioavailability by the oral route, even distribution throughout the tissues, including the central nervous system and the cerebro-spinal fluid, a long half-life (permitting once daily administration), and low binding to plasma proteins. It is excreted mainly as unchanged drug in the urine. Fluconazole is a broad-spectrum antifungal agent, especially effective against Candida spp., Cryptococcus neoformans and dermatophytes. Its antifungal efficacy was mainly proved by testing in animal models, since there is no relationship between in vitro and in vivo activities. It possesses a low toxicity and it is well-tolerated. Fluconazole is currently marketed for the treatment of oropharyngeal candidiasis in immuno-compromised patients and of atrophic oral candidiasis. Its place in the treatment of opportunistic mycoses in human immuno-deficiency virus-positive patients, in particular cryptococcal meningitis, is still under investigation but is promising.