Development and validation of a risk prediction model for linezolid-induced thrombocytopenia in elderly patients

OBJECTIVES

Linezolid is the first oxazolidinone antimicrobial agent developed for treating multi-drug-resistant gram-positive bacterial infections. The study aimed to investigate the risk factors of linezolid (LI)-induced thrombocytopenia (LI-TP) and to develop and validate a risk prediction model to identify elderly patients at high risk of developing LI-TP during linezolid therapy.

METHODS

A retrospective cohort study was performed at Zhongshan Hospital, FuDan University, China. The study involved elderly Chinese patients aged ≥65 years administered with linezolid (600 mg) twice a day between January 2015 and April 2021. We collected the patients' clinical characteristics and demographic data from electronic medical records, and compared the differences between LI-TP patients and those who had not developed thrombocytopenia (NO-TP) after linezolid treatment. The risk prediction model was developed based on the regression coefficient generated from logistic regression model.

RESULTS

A total of 343 inpatients were enrolled from January 2015 to August 2020 and were used as the training set. Among them, 67 (19.5%) developed LI-TP. Multivariate logistic regression analysis revealed that baseline platelet counts <150×109·L-1 (odds ratio (OR)=3.576; p<0.001), age ≥75 years (OR=2.258; p=0.009), estimated glomerular filtration rate (eGFR <60 mL·(min·1.73 m2)-1 (OR=2.553; p=0.002), duration of linezolid therapy ≥10 d (OR=3.218; p<0.001), intensive care unit (ICU) admittance (OR=2.682; p=0.004), concomitant piperacillin-tazobactam (OR=3.863; p=0.006) were independent risk factors for LI-TP in elderly patients. The LI-TP risk prediction model was established using a scoring method based on the regression coefficient and exhibited a good discriminative power, with an area under the curve (AUC) of 0.795 (95% confidence interval (CI) 0.740 to 0.851) and 0.849 (95% CI 0.760 to 0.939) in the training set (n=343) and validation set (n=90) respectively.

CONCLUSIONS

These findings indicate that duration of linezolid therapy, age, eGFR, ICU admittance, baseline platelet counts, concomitant piperacillin-tazobactam were significantly associated with LI-TP in elderly patients. A risk prediction model based on these risk factors showed a good discriminative performance and may be useful for clinicians to identify patients at high risk of developing LI-TP.

Oral Linezolid Induced Early Onset Hepatic Encephalopathy- A Case Report of 65-year Old Diabetic Female

INTRODUCTION

Linezolid is increasingly utilized to treat gram-positive bacteria that are resistant to other antibiotics like vancomycin-resistant Staphylococcus aureus, methicillinresistant Staphylococcus aureus as well as drug-resistant tuberculosis. It acts by inhibiting protein synthesis in bacteria. Although it is a relatively safe medicine, many reports of hepatotoxicity and neurotoxicity linked to long-term usage have been received but patients with pre-existing risk factors, such as diabetes and alcoholism, may have toxicity even after short-term use of linezolid.

CASE PRESENTATION

Here we are presenting a case of a 65-year-old female with diabetes who developed hepatic encephalopathy after one week of treatment with linezolid prescribed for nonhealing diabetic ulcer after a culture sensitivity test. After the use of linezolid 600 mg BD for 8 days patient developed altered sensorium and breathlessness and had high bilirubin, SGOT, and SGPT. She was diagnosed with hepatic encephalopathy. Linezolid was withdrawn and after 10 days all laboratory parameters for liver function test were improved.

CONCLUSION

Care should be taken when prescribing linezolid in such patients with pre-existing risk factors as they are prone to develop hepatotoxic and neurotoxic adverse effects even after short-term use of linezolid.

A phase I study of the safety, tolerability, and pharmacokinetics of contezolid acefosamil after intravenous and oral administration in healthy Chinese subjects

Contezolid acefosamil (also known as MRX-4), a prodrug of contezolid, is under development for treatment of multidrug-resistant Gram-positive bacterial infections. A phase I single ascending dose (SAD) and multiple-dose placebo-controlled study was conducted to assess the safety, tolerability, and pharmacokinetics (PK) of contezolid acefosamil in healthy Chinese subjects following intravenous (IV) and oral administration. Adverse events (AEs) and PK parameters were assessed appropriately. All subjects (n = 70) completed the trial. Overall, 67 cases of treatment-emergent adverse events (TEAEs) were observed in 49.1% (27 of 55) of the subjects receiving contezolid acefosamil. All TEAEs were mild in severity. No serious AEs or deaths were reported. After IV SAD (500-2,000 mg), the corresponding C max of the active drug contezolid increased from 1.95 ± 0.57 to 15.61 ± 4.88 mg/L, AUC0-inf from 40.25 ± 10.12 to 129.41 ± 38.30 h·mg/L, median T max from 2.00 to 2.75 h, and mean t 1/2 from 13.33 to 16.74 h. Plasma contezolid reached steady state on day 6 after multiple IV doses, with an accumulation ratio of 2.20-2.96. Oral SAD of 500 and 1,500 mg resulted in contezolid C max of 8.66 ± 2.60 and 37.10 ± 8.66 mg/L, AUC0-inf of 30.44 ± 7.33 and 162.36 ± 47.08 h·mg/L, and median T max of 2.50 and 2.98 h. Contezolid reached steady state on day 5 after multiple oral doses of 1,500 mg without significant accumulation. Contezolid C max and AUC0-inf increased with the dose of contezolid acefosamil. The good safety and PK profiles in this SAD and multiple-dose study can support further clinical development of contezolid acefosamil.

Efficacy and safety of tedizolid for the treatment of ventilated gram-positive hospital-acquired or ventilator-associated bacterial pneumonia in Japanese patients: Results from a subgroup analysis of a phase 3, randomized, double-blind study comparing tedizolid and linezolid

INTRODUCTION

The results from the phase 3 study that evaluated the efficacy and safety of tedizolid phosphate, an oxazolidinone drug, for the treatment of gram-positive ventilated hospital-acquired bacterial pneumonia (vHABP)/ventilator-associated bacterial pneumonia (VABP) compared with linezolid (VITAL study), have been previously reported. We conducted a subgroup analysis to report the data obtained from Japanese patients enrolled in this study.

METHODS

Patients aged ≥18 years with vHABP/VABP likely to be caused by gram-positive cocci were randomized 1:1 to tedizolid phosphate 200 mg once daily for 7 days or linezolid 600 mg twice daily for 10 days. In both treatment groups, patients with concurrent gram-positive bacteremia were treated for 14 days. Primary efficacy endpoints were day 28 all-cause mortality (ACM) and investigator-assessed clinical response at test-of-cure (TOC) in the intention-to-treat population. Safety outcomes included assessment of treatment-emergent adverse events.

RESULTS

Fifty-three Japanese patients were randomized at received study drug (tedizolid, n = 28; linezolid, n = 25). Demographics and characteristics were generally similar between treatment groups. Rates of day 28 ACM were 10.7% and 20.0% with tedizolid and linezolid, respectively (difference, 9.3%; 95% CI, -10.1 to 28.7). Rates of investigator-assessed clinical cure at TOC were 78.6% and 72.0% with tedizolid and linezolid, respectively (difference, 6.6%; 95% CI, -16.7 to 29.8). Tedizolid phosphate was generally well tolerated and no new safety concerns were observed in the Japanese subgroup.

CONCLUSION

The results from this subgroup analysis suggest generally favorable efficacy and safety of tedizolid in adult Japanese patients with vHABP/VABP. (ClinicalTrials.gov identifier: NCT02019420).

Long-term safety and efficacy of anacetrapib in patients with atherosclerotic vascular disease

AIMS

REVEAL was the first randomized controlled trial to demonstrate that adding cholesteryl ester transfer protein inhibitor therapy to intensive statin therapy reduced the risk of major coronary events. We now report results from extended follow-up beyond the scheduled study treatment period.

METHODS AND RESULTS

A total of 30 449 adults with prior atherosclerotic vascular disease were randomly allocated to anacetrapib 100 mg daily or matching placebo, in addition to open-label atorvastatin therapy. After stopping the randomly allocated treatment, 26 129 survivors entered a post-trial follow-up period, blind to their original treatment allocation. The primary outcome was first post-randomization major coronary event (i.e. coronary death, myocardial infarction, or coronary revascularization) during the in-trial and post-trial treatment periods, with analysis by intention-to-treat. Allocation to anacetrapib conferred a 9% [95% confidence interval (CI) 3-15%; P = 0.004] proportional reduction in the incidence of major coronary events during the study treatment period (median 4.1 years). During extended follow-up (median 2.2 years), there was a further 20% (95% CI 10-29%; P < 0.001) reduction. Overall, there was a 12% (95% CI 7-17%, P < 0.001) proportional reduction in major coronary events during the overall follow-up period (median 6.3 years), corresponding to a 1.8% (95% CI 1.0-2.6%) absolute reduction. There were no significant effects on non-vascular mortality, site-specific cancer, or other serious adverse events. Morbidity follow-up was obtained for 25 784 (99%) participants.

CONCLUSION

The beneficial effects of anacetrapib on major coronary events increased with longer follow-up, and no adverse effects emerged on non-vascular mortality or morbidity. These findings illustrate the importance of sufficiently long treatment and follow-up duration in randomized trials of lipid-modifying agents to assess their full benefits and potential harms.

TRIAL REGISTRATION

International Standard Randomized Controlled Trial Number (ISRCTN) 48678192; ClinicalTrials.gov No. NCT01252953; EudraCT No. 2010-023467-18.

Use of Pistia stratiotes for phytoremediation of water resources contaminated by clomazone

The Pistia stratiotes L. was tested for phytoremediation potential of the compound clomazone in water. Clomazone is a post-emergent herbicide marketed as Gamit^®. Five groups with four samples each were evaluated, a low concentration control (LCC: 37.86 mg L^-1), low concentration treatment (LCT: 38.16 mg L^-1), high concentration control (HCC: 54.71 mg L^-1), high concentration treatment (HCT: 54.33 mg L^-1), and a plant control group (PCG). Plant resistance to clomazone at determined concentrations and their ability to remove the herbicide from water by HPLC over 24 days were evaluated. The results demonstrate that P. stratiotes has high resistance to clomazone exposure and was able to eliminate up to 90% of the herbicide residues during the experimental period. Under dissipation by P. stratiotes in water, clomazone had a halflife of 19.6 days for in the control treatments, LCC and HCC, and 8.0 days in the treatment groups, LCT and HCT. This study indicates that Pistia stratiotes is an effective phytoremediation agent for the herbicide clomazone in water.

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND

Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization.

RESULTS

During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events.

CONCLUSIONS

Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .).

Linezolid for the Treatment of Patients with Central Nervous System Infection

Objective:

To review the available evidence regarding the use of linezolid for the treatment of patients with central nervous system (CNS) infections.

Data Sources:

Relevant studies were identified through searches of the PubMed, Current Contents, and Cochrane databases (publications archived until October 2006).

Study Selection and Data Extraction:

Case reports, case series, prospective and retrospective studies, and randomized controlled trials were eligible for inclusion in our review if they evaluated the effectiveness and safety of linezolid for the treatment of patients with CNS infections.

Data Synthesis:

In 18 (42.9%) of the 42 relevant cases identified, patients had undergone neurosurgical operations and/or had prosthetic devices. Meningitis was the most common CNS infection, accounting for 20 (47.6%) cases. Other CNS infections included brain abscesses (14; 33.3%), ventriculitis (5; 11.9%), and ventriculo-peritoneal shunt infection (3; 7.1%). In the 39 patients in whom the responsible pathogen was isolated, those predominantly responsible for the CNS infections were: penicillin–nonsusceptible Streptococcus pneumoniae (7; 17.9%), vancomycin-resistant enterococci (6; 15.4%), Nocardia spp. (5; 12.8%), methicillin-resistant Staphylococcus epidermidis (4; 10.3%), and methicillin-resistant Staphylococcus aureus (3; 7.7%). Of the 42 patients who received linezolid for the treatment of CNS infections, 38 (90.5%) were either cured or showed clinical improvement of the infection. The mean duration of follow-up was 7.2 months; no recurrent CNS infection was reported.

Conclusions:

The limited published data suggest that linezolid may be considered for the treatment of patients with CNS infections in cases of failure of previously administered treatment or limited available options.

LInezolid for the Treatment of Nocardia spp. Infections

Objective:

To review the available evidence regarding the use of linezolid for the treatment of Nocardia spp. infections.

Data Sources:

Data were identified through a search of MEDLINE (1966-May 2007), American Search Premier (1975-May 2007), International Pharmaceutical Abstracts (1960-2007), Science Citation Index Expanded (1996-2007), and Cochrane Databases (publications archived until May 2007) using the terms linezolid and Nocardia.

Study Selection and Data Extraction:

Prospective and retrospective studies, case reports, case series, and in vitro studies were eligible for inclusion if they used linezolid for nocardiosis regardless of site of infection and outcome.

Data Synthesis:

We identified 11 published cases of linezolid use for Nocardia spp. infections. The predominant species isolated were N. asteroides (n=4; 36%) and N. farcinica (n= 3; 27%). Nocardiosis with central nervous system involvement (n= 7; 64%) or disseminated disease (n= 4; 36%) were most common. The main reason for discontinuation of previous antimicrobials was most often related to adverse effects (n= 5; 45%), followed by clinical failure (n = 3; 27%). Linezolid was associated with cure or improvement in all cases (n =11; 100%). However, the majority of patients developed serious complications that may have led to premature discontinuation of therapy with linezolid, including myelosuppression (n = 5; 45%) or possible/confirmed peripheral neuropathy (n = 2; 18%).

Conclusions:

The limited published data suggest that linezolid appears to be an effective alternative to trimethoprim/sulfamethoxazole for the treatment of nocardiosis. Unfortunately, the high cost and potentially serious long-term toxicities of linezolid appear to limit its use and relegate it to salvage therapy alone or in combination with other antimicrobials.

Linezolid-Associated Serotonin Syndrome After Concomitant Treatment With Citalopram and Mirtazepine in a Critically Ill Bone Marrow Transplant Recipient

Linezolid was initially discovered as an antidepressant because of its effect on blocking intracellular metabolism of serotonin, norepinephrine, and other biogenic amines. As time passed, it was realized that linezolid possessed antibacterial activity, and linezolid has been developed and marketed as such. In medicine we are quick to categorize drugs into specific classes as a mechanism to recall indication and use. By classifying linezolid as an antibacterial, it is common to forget about its antidepressant roots. A case report involving linezolid with citalopram and mirtazepine in the precipitation of serotonin syndrome in a critically ill bone marrow transplant patient is described in this article.

[Myocardial infarction in a patient free of coronary artery disease]

Triptans are widely used for treating migraine attacks. Their mechanism of action is attributable to cerebrovascular vasoconstriction. Vasoconstriction can occur also in the coronary arteries. Mild chest symptoms not related to myocardial ischemia have been reported among triptan users. Severe cardiovascular events have also been reported, but they are extremely rare. There are few observational studies focusing on the cardiovascular risks of triptans. Triptans are nevertheless considered contra-indicated in patients with coronary artery disease. We report a case of zolmitriptan-induced myocardial infarction in a patient free of coronary artery disease.

Nonclinical and pharmacokinetic assessments to evaluate the potential of tedizolid and linezolid to affect mitochondrial function

Prolonged treatment with the oxazolidinone linezolid is associated with myelosuppression, lactic acidosis, and neuropathies, toxicities likely caused by impairment of mitochondrial protein synthesis (MPS). To evaluate the potential of the novel oxazolidinone tedizolid to cause similar side effects, nonclinical and pharmacokinetic assessments were conducted. In isolated rat heart mitochondria, tedizolid inhibited MPS more potently than did linezolid (average [± standard error of the mean] 50% inhibitory concentration [IC50] for MPS of 0.31 ± 0.02 μM versus 6.4 ± 1.2 μM). However, a rigorous 9-month rat study comparing placebo and high-dose tedizolid (resulting in steady-state area under the plasma concentration-time curve values about 8-fold greater than those with the standard therapeutic dose in humans) showed no evidence of neuropathy. Additional studies explored why prolonged, high-dose tedizolid did not cause these mitochondriopathic side effects despite potent MPS inhibition by tedizolid. Murine macrophage (J774) cell fractionation studies found no evidence of a stable association of tedizolid with eukaryotic mitochondria. Monte Carlo simulations based on population pharmacokinetic models showed that over the course of a dosing interval using standard therapeutic doses, free plasma concentrations fell below the respective MPS IC50 in 84% of tedizolid-treated patients (for a median duration of 7.94 h) and 38% of linezolid-treated patients (for a median duration of 0 h). Therapeutic doses of tedizolid, but not linezolid, may therefore allow for mitochondrial recovery during antibacterial therapy. The overall results suggest that tedizolid has less potential to cause myelosuppression and neuropathy than that of linezolid during prolonged treatment courses. This, however, remains a hypothesis that must be confirmed in clinical studies.

Treatment of mediastinitis due to methicillin-resistant Staphylococcus aureus in a renal dysfunction patient undergoing adjustments to the linezolid dose

This study is the first case report of the treatment of methicillin-resistant Staphylococcus aureus (MRSA) mediastinitis using therapeutic drug monitoring of the serum and wound exudate concentrations of linezolid in a renal dysfunction patient. In the present study, the serum trough concentration of linezolid was maintained between 2 and 7 μg/mL. Therapeutic drug monitoring dosage adjustments may be especially useful in patients with renal dysfunction and severe MRSA infection.

[Antibiotics for treatment of infections by methicillin-resistant Staphylococcus aureus (MRSA)]

Over the last 50 years methicillin-resistant S. aureus (MRSA) spread globally. Vancomycin is still the most recommended antibiotic for MRSA-infections. Teicoplanin is an alternative glycopeptide with longer elimination half-life. Telavancin is a more recently developed derivative of vancomycin with similar clinical efficacy as vancomycin. It is not recommended for treatment of patients with renal insufficiency. Nephrotoxicity limits the therapeutic use of glycopeptide antibiotics. The oxazolidinone linezolid exhibits similar to superior therapeutic efficacy. Hematologic controls are necessary during treatment with this antibacterial agent. Neurotoxic effects have been observed mainly in patients who received prolonged linezolid treatment. Attention must be paid to possible interactions with concomitantly given drugs acting on the serotonergic system. New therapeutic options arise with ceftaroline, the first β-lactam antibiotic with activity against MRSA. However, controlled clinical trials with pulmonary MRSA infections have not been conducted with ceftaroline. Daptomycin, a lipopeptide, and tigecycline, a glycylcyclin are active in vitro against MRSA as well, but are also not indicated in pulmonary MRSA infections. These antibiotics show in an exemplary manner that antibacterial activity in vitro is an important prerequisite, but relevant data for a therapeutic decision should be derived from randomized controlled clinical double-blind trials.

Linezolid induced black hairy tongue: a rare side effect

Linezolid induced black hairy tongue is a rare benign reversible side effect of linezolid therapy. We report a case of a 61 year old diabetic lady who developed thrombocytopenia and black hairy discoloration of the tongue after being prescribed linezolid for foot osteomyelitis by the orthopaedic surgeon. Patient was encouraged to practice good oral dental hygiene, advised to use a soft tooth brush, regular mouth wash and baking soda containing tooth paste. The condition resolved four weeks after cessation of the antibiotic therapy.

Once-weekly dalbavancin versus daily conventional therapy for skin infection

BACKGROUND

Dalbavancin, a lipoglycopeptide antibiotic agent that is active against gram-positive pathogens, has a long plasma half-life, allowing for once-weekly dosing. DISCOVER 1 and DISCOVER 2 were identically designed noninferiority trials of dalbavancin for the treatment of acute bacterial skin and skin-structure infection.

METHODS

We randomly assigned patients to receive dalbavancin intravenously on days 1 and 8 or vancomycin intravenously for at least 3 days with the option to switch to oral linezolid to complete 10 to 14 days of therapy. The primary end point, early clinical response, required the cessation of spread of infection-related erythema and the absence of fever at 48 to 72 hours. Secondary end points at the end of therapy included clinical status and investigator's assessment of outcome.

RESULTS

Analysis of the primary end point showed noninferiority of dalbavancin in both DISCOVER 1 and DISCOVER 2. In the pooled analysis, 525 of 659 patients (79.7%) in the dalbavancin group and 521 of 653 (79.8%) in the vancomycin-linezolid group had an early clinical response indicating treatment success (weighted difference, -0.1 percentage point; 95% confidence interval, -4.5 to 4.2). The outcomes were similar in the analyses by study and the pooled analyses of clinical status at the end of therapy and the investigator's assessment of outcome. For patients infected with Staphylococcus aureus, including methicillin-resistant S. aureus, clinical success was seen in 90.6% of the patients treated with dalbavancin and 93.8% of those treated with vancomycin-linezolid. Adverse events and study days with an adverse event were less frequent in the dalbavancin group than in the vancomycin-linezolid group. The most common treatment-related adverse events in either group were nausea, diarrhea, and pruritus.

CONCLUSIONS

Once-weekly intravenous dalbavancin was not inferior to twice-daily intravenous vancomycin followed by oral linezolid for the treatment of acute bacterial skin and skin-structure infection. (Funded by Durata Therapeutics; DISCOVER 1 and DISCOVER 2 ClinicalTrials.gov numbers, NCT01339091 and NCT01431339.).

Zolmitriptan for acute migraine attacks in adults

BACKGROUND

Migraine is a common, disabling condition and a burden for the individual, health services, and society. Zolmitriptan is an abortive medication for migraine attacks, belonging to the triptan family. These medicines work in a different way to analgesics such as paracetamol and ibuprofen.

OBJECTIVES

To determine the efficacy and tolerability of zolmitriptan compared to placebo and other active interventions in the treatment of acute migraine attacks in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and the Oxford Pain Relief Database, together with three online databases (www.astrazenecaclinicaltrials.com, www.clinicaltrials.gov, and apps.who.int/trialsearch) for studies to 12 March 2014. We also searched the reference lists of included studies and relevant reviews.

SELECTION CRITERIA

We included randomised, double-blind, placebo- or active-controlled studies, with at least 10 participants per treatment arm, using zolmitriptan to treat a migraine headache episode.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We used numbers of participants achieving each outcome to calculate risk ratios and numbers needed to treat for an additional beneficial effect (NNT) or harmful effect (NNH) compared with placebo or a different active treatment.

MAIN RESULTS

Twenty-five studies (20,162 participants) compared zolmitriptan with placebo or an active comparator. The evidence from placebo-controlled studies was of high quality for all outcomes except 24 hour outcomes and serious adverse events where only limited data were available. The majority of included studies were at a low risk of performance, detection and attrition biases, but did not adequately describe methods of randomisation and concealment.Most of the data were for the 2.5 mg and 5 mg doses compared with placebo, for treatment of moderate to severe pain. For all efficacy outcomes, zolmitriptan surpassed placebo. For oral zolmitriptan 2.5 mg versus placebo, the NNTs were 5.0, 3.2, 7.7, and 4.1 for pain-free at two hours, headache relief at two hours, sustained pain-free during the 24 hours postdose, and sustained headache relief during the 24 hours postdose, respectively. Results for the oral 5 mg dose were similar to the 2.5 mg dose, while zolmitriptan 10 mg was significantly more effective than 5 mg for pain-free and headache relief at two hours. For headache relief at one and two hours and sustained headache relief during the 24 hours postdose, but not pain-free at two hours, zolmitriptan 5 mg nasal spray was significantly more effective than the 5 mg oral tablet.For the most part, adverse events were transient and mild and were more common with zolmitriptan than placebo, with a clear dose response relationship (1 mg to 10 mg).High quality evidence from two studies showed that oral zolmitriptan 2.5 mg and 5 mg provided headache relief at two hours to the same proportion of people as oral sumatriptan 50 mg (66%, 67%, and 68% respectively), although not necessarily the same individuals. There was no significant difference in numbers experiencing adverse events. Single studies reported on other active treatment comparisons but are not described further because of the small amount of data.

AUTHORS' CONCLUSIONS

Zolmitriptan is effective as an abortive treatment for migraine attacks for some people, but is associated with increased adverse events compared to placebo. Zolmitriptan 2.5 mg and 5 mg benefited the same proportion of people as sumatriptan 50 mg, although not necessarily the same individuals, for headache relief at two hours.

Use of linezolid in children: an overview of recent advances

Linezolid is the first member of a new generation of antibiotics, the synthetic oxazolidinones, to become available, with a broad spectrum of in vitro activity against gram-positive organisms, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecalis and vancomycin-resistant E. faecium. Linezolid is showing great promise currently for the treatment of multiresistant gram-positive bacterial infections, especially complicated skin infections, catheter-induced bacteremia or nosocomial pneumonia both in the community and in a hospital setting, in children and in adults. Although most recent reports are favorable and anticipatory of a more extensive use of linezolid in appropriately selected pediatric population groups in the near future, following treatment failure of conventional antimicrobial agents, more clinical trials are, however, required to investigate the safety profile and tolerability of this new antibiotic in the pediatric population.

Zolmitriptan (Zomig®)

New triptans are being released in rapid succession with each addition demonstrating some specific pharmacokinetic properties, which may be translated into clinical advantages. Zolmitriptan (Zomig) offers a range of alternatives to migraine sufferers. The conventional tablet is consistently effective across a wide range of migraine subtypes. The orally disintegrating tablet offers an effective option for those migraineurs who are nauseated or need to take their medication earlier in the course of their migraine. Since it can be taken without fluid, the orally disintegrating tablet may be consistently used early in the migraine attack when the pain is still mild. The nasal spray aggregates all the benefits of the oral formulations and has a faster onset of action. The 5-mg dose of all three forms of zolmitriptan offers additional benefits over the 2.5-mg dose at early time points. The physician can now choose the optimum route of delivery of zolmitriptan to stop the headache, increase the likelihood of reducing disability and restore the patient to complete functionality.

Role of linezolid in the treatment of complicated skin and soft tissue infections

Staphylococcus aureus is the most common cause of complicated skin and soft tissue infections (cSSTIs). Antibiotic choices for these infections continue to evolve. History has seen penicillin progress to antistaphylococcal penicillins and cephalosporins, but these drugs are now giving way to drugs that are effective against methicillin-resistant S. aureus (MRSA). While vancomycin has been the gold standard to treat MRSA infections, newer therapeutic options have been developed over the last 5 years. These include quinupristin-dalfopristin, daptomycin, tigecycline and linezolid, which is the focus for this review. Linezolid is efficacious in the treatment of cSSTIs (including diabetic foot infections) caused by Gram-positive organisms (including MRSA), with a well-defined safety profile and straightforward dosing. It is also approved for nosocomial pneumonia, community-acquired pneumonia and uncomplicated skin and skin structure infections. Linezolid has an oral and parenteral formulation, which are equivalent. The oral formulation has the potential to offer economic benefits as compared with other therapies. Currently, there are only a few new antibiotics in development with MRSA activity. The proper use of all antibiotics, including these newer agents, is increasingly important if we are to slow the evolution of microbial resistance.

Cholesteryl ester transfer protein inhibitors in the treatment of dyslipidemia: a systematic review and meta-analysis

Cholesteryl ester transfer protein (CETP) inhibitors are gaining substantial research interest for raising high density lipoprotein cholesterol levels. The aim of the research was to estimate the efficacy and safety of cholesteryl ester transfer protein inhibitors as novel lipid modifying drugs. Systematic searches of English literature for randomized controlled trials (RCT) were collected from MEDLINE, EBASE, CENTRAL and references listed in eligible studies. Two independent authors assessed the search results and only included the double-blind RCTs by using cholesteryl ester transfer protein inhibitors as exclusively or co-administrated with statin therapy irrespective of gender in enrolled adult subjects. Two independent authors extracted the data by using predefined data fields. Of 503 studies identified, 14 studies met the inclusion criteria, and 12 studies were included into the final meta-analysis. Our meta-analysis revealed that CETP inhibitors increased the HDL-c levels (n = 2826, p<0.00001, mean difference (MD) = 20.47, 95% CI [19.80 to 21.15]) and total cholesterol (n = 3423, p = 0.0002, MD = 3.57, 95%CI [1.69 to 5.44] to some extent combined with a reduction in triglyceride (n = 3739, p<0.00001, MD = -10.47, 95% CI [-11.91 to -9.03]) and LDL-c (n = 3159, p<0.00001, MD = -17.12, 95% CI [-18.87 to -15.36]) irrespective of mono-therapy or co-administration with statins. Subgroup analysis suggested that the lipid modifying effects varied according to the four currently available CETP inhibitors. CETP inhibitor therapy did not increase the adverse events when compared with control. However, we observed a slight increase in blood pressure (SBP, n = 2384, p<0.00001, MD = 2.73, 95% CI [2.14 to 3.31], DBP, n = 2384, p<0.00001, MD = 1.16, 95% CI [0.73 to 1.60]) after CETP inhibitor treatment, which were mainly ascribed to the torcetrapib treatment subgroup. CETP inhibitors therapy is associated with significant increase in HDL-c and decrease in triglyceride and LDL-c with satisfactory safety and tolerability in patients with dyslipidemia. However, the side-effect on blood pressure deserves more consideration in future studies.

Pancytopenia and lactic acidosis associated with linezolid use in a patient with empyema

OBJECTIVE

To describe a patient who developed pancytopenia and lactic acidosis after receiving linezolid therapy.

CASE SUMMARY

A 32-year-old man with past medical history of heart failure, hypertension received a 14-day course of linezolid for treatment of empyema with broncho-pleural fistula. During his follow up visit, he was found to be septic and further evaluation showed pancytopenia, acidosis and elevated liver enzymes. With the exclusion of other possible etiologies, the time course to development of these laboratory abnormalities correlated with the use of linezolid. Antibiotics were switched subsequently and the labs improved after reaching a nadir on the fourth day after stopping linezolid.

DISCUSSION

Linezolid was noted to cause time and dose-dependent reversible myelosuppression in preclinical studies. There are several case reports of throinbocytopenia occurring with linezolid use, but only few cases of pancytopenia and lactic acidosis are reported. Exact mechanism of toxicity is unknown, but many hypothesize it to be similar to chloramphenicol marrow toxicity because of the cross-reactivity to mitochondrial ribosomes.

CONCLUSIONS

Clinicians should be aware of linezolid as a drug capable of causing pancytopenia, lactic acidosis and elevated liver enzymes. While recovery is usually complete following withdrawal of the drug, we need to still monitor for these rare but severe complications; and consider treating only for a shorter duration, if possible.

Linezolid: A New Antibiotic for Newborns and Children?

Staphylococcus aureus remains one of the most common and troublesome microorganisms causing disease in humans, despite the development of effective antibiotics. Linezolid is a member of a new class of synthetic antibiotics called oxazolidinones, introduced into therapy due to the increasing resistance of Gram-positive pathogens to traditional antibiotics. Information about the pharmacokinetics and tolerability profile of linezolid in the pediatric population mostly derive from adult studies and especially in the neonatal field relatively few data are available. Here we summarize linezolid's characteristics and report data available in the literature regarding linezolid use in newborns and children. For this purpose, a Medline search was performed between 1990 and 2006 involving the term "linezolid" combined with the terms "newborn", "infant", "child", "pediatrics". Additional information was obtained from Reactions Weekly.

The Effectiveness and Safety of Oral Linezolid for the Primary and Secondary Treatment of Osteomyelitis

The pharmacokinetic profile of oral linezolid makes it an attractive alternative for the treatment of osteomyelitis. Few studies have described the efficacy of linezolid in the treatment of osteomyelitis. A retrospective, observational analysis was conducted at Edward Hines, Jr. VA Hospital. Patients who received oral linezolid from June 2000 to December 2002 were identified from pharmacy records. Forty-two patients who received oral linezolid for osteomyelitis at our institution were identified. Only patients who had received at least six weeks of linezolid therapy were evaluated for clinical effectiveness. Patients were also evaluated for adverse drug reactions due to linezolid. The clinical cure rate was 55% for the 20 patients who received at least six weeks of therapy. Adverse events included gastrointestinal disturbances (15%), thrombocytopenia (10%), anemia (10%), neutropenia (5%) and rash (5%). The authors conclude that oral linezolid is an alterative to intravenous antibiotics for the treatment of osteomyelitis.

Linezolid versus vancomycin for skin and soft tissue infections

BACKGROUND

The morbidity and treatment costs associated with skin and soft tissue infections (SSTIs) are high. Linezolid and vancomycin are antibiotics that are commonly used in treating skin and soft-tissue infections, specifically those infections due to methicillin-resistant Staphylococcus aureus (MRSA).

OBJECTIVES

To compare the effects and safety of linezolid and vancomycin for treating people with SSTIs.

SEARCH METHODS

In May 2013 we conducted searches of the following databases: Cochrane Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; and EBSCO CINAHL. We also contacted manufacturers for details of unpublished and ongoing trials. We scrutinised citations within all obtained trials and major review articles to identify any additional trials.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing linezolid with vancomycin in the treatment of SSTIs.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed risk of bias and extracted data. The primary outcomes were clinical cure, microbiological cure, and SSTI-related and treatment-related mortality. We performed subgroup analyses according to age, and whether the infection was due to MRSA.

MAIN RESULTS

We included nine RCTs (3144 participants). Linezolid was associated with a significantly better clinical (RR 1.09, 95% CI 1.03 to 1.16) and microbiological cure rate in adults (RR 1.08, 95% CI 1.01 to 1.16). For those infections due to MRSA, linezolid was significantly more effective than vancomycin in clinical (RR 1.09, 95% CI 1.03 to 1.17) and microbiological cure rates (RR 1.17, 95% CI 1.04 to 1.32). No RCT reported SSTI-related and treatment-related mortality. There was no significant difference in all-cause mortality between linezolid and vancomycin (RR 1.44, 95% CI 0.75 to 2.80). There were fewer incidents of red man syndrome (RR 0.04, 95% CI 0.01 to 0.29), pruritus (RR 0.36, 95% CI 0.17 to 0.75) and rash (RR 0.27, 95% CI 0.12 to 0.58) in the linezolid group compared with vancomycin, however, more people reported thrombocytopenia (RR 13.06, 95% CI 1.72 to 99.22), and nausea (RR 2.45, 95% CI 1.52 to 3.94) when treated with linezolid. It seems, from the available data, that length of stay in hospital was shorter for those in the linezolid group than the vancomycin group. The daily cost of outpatient therapy was less with oral linezolid than with intravenous vancomycin. Although inpatient treatment with linezolid cost more than inpatient treatment with vancomycin per day, the median length of hospital stay was three days shorter with linezolid. Thus, total hospital charges per patient were less with linezolid treatment than with vancomycin treatment.

AUTHORS' CONCLUSIONS

Linezolid seems to be more effective than vancomycin for treating people with SSTIs, including SSTIs caused by MRSA. The available evidence is at high risk of bias and is based on studies that were supported by the pharmaceutical company that makes linezolid. Further well-designed, independently-funded, RCTs are needed to confirm the available evidence.

Filgrastim therapy in a child with neutropenia induced by linezolid

We describe the case of a young child with multidrug-resistant tuberculosis, treated with linezolid. The child developed severe neutropenia after 5 months of treatment. Filgrastim was used, a drug that officially is not indicated for non-cytostatic drug-induced neutropenia. This allowed the fast recovery of the patient’s neutrophil-count. However, more experience with the off-label use of filgrastrim is needed in the pediatric population.

Serious treatment related adverse drug reactions amongst anti-retroviral naïve MDR-TB patients

BACKGROUND

Globally treatment outcomes for multidrug-resistant Mycobacterium tuberculosis (MDR-TB) remain poor and this is compounded by high drug toxicity. Little is known about the influence of adverse drug reactions (ADRs) on treatment outcomes in South Africa.

METHODS

We evaluated the impact of severe ADRs among a prospective cohort of MDR-TB patients in South Africa (2000-2004). The HIV-infected study participants were anti-retroviral naïve.

RESULTS

Of 2,079 patients enrolled, 1,390 (66.8%) were included in this analysis based on known HIV test results (39.1% HIV-infected). At least one severe ADR was reported in 83 (6.9%) patients with ototoxicity being the most frequent ADR experienced (38.9%).

CONCLUSIONS

We found that being HIV-infected but antiretroviral naïve did not increase occurrence of SADRs in patients on second-line anti-tuberculosis drugs. Early screening and proactive management of ADRs in this patient population is essential, especially given the rollout of decentralized care and the potential for overlapping toxicity of concomitant MDR-TB and HIV treatment.

Linezolid: Pharmacokinetic and Pharmacodynamic Evaluation of Coadministration with Pseudoephedrine HCl, Phenylpropanolamine HCl, and Dextromethorphan HBr

Linezolid is a novel oxazolidinone antibiotic with mild reversible monoamine oxidase inhibitor (MAOI) activity. The potential for interaction with over-the-counter (OTC) medications requires quantification. The authors present data evaluating the pharmacokinetic and pharmacodynamic responses to coadministration of oral linezolid with sympathomimetics (pseudoephedrine and phenylpropanolamine) and a serotonin reuptake inhibitor (dextromethorphan). Following coadministration with linezolid, minimal but statistically significant increases were observed in pseudoephedrine and phenylpropanolamine plasma concentrations; a minimal but statistically significant decrease was observed in dextrorphan (the primary metabolite of dextromethorphan) plasma concentrations. Increased blood pressure (BP) was observed following the coadministration of linezolid with either pseudoephedrine or phenylpropanolamine; no significant effects were observed with dextromethorphan. None of these coadministered drugs had a significant effect on linezolid pharmacokinetics. Minimal numbers of adverse events were reported. Potentiation of sympathomimetic activity by linezolid was judged not to be clinically significant, but patients sensitive to the effects of increased BP due to predisposing factors should be treated cautiously. No restrictions are indicated for the coadministration of dextromethorphan and linezolid.

The efficacy and safety of linezolid and glycopeptides in the treatment of Staphylococcus aureus infections

To assess the effectiveness and safety of linezolid in comparison with glycopeptides (vancomycin and teicoplanin) for the treatment of Staphylococcus aureus infections, we conducted a meta-analysis of relevant randomized controlled trials. A thorough search of Pubmed and other databases was performed. Thirteen trials on 3863 clinically assessed patients were included. Linezolid was slightly more effective than glycopeptides in the intent-to-treat population (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01–1.10), was more effective in clinically assessed patients (OR 95% CI: 1.38, 1.17–1.64) and in all microbiologically assessed patients (OR 95% CI: 1.38, 1.15–1.65). Linezolid was associated with better treatment in skin and soft-tissue infections (SSTIs) patients (OR 95% CI: 1.61, 1.22–2.12), but not in bacteraemia (OR 95% CI: 1.24, 0.78–1.97) or pneumonia (OR 95% CI: 1.25, 0.97–1.60) patients. No difference of mortality between linezolid and glycopeptides was seen in the pooled trials (OR 95% CI: 0.98, 0.83–1.15). While linezolid was associated with more haematological (OR 95% CI: 2.23, 1.07–4.65) and gastrointestinal events (OR 95% CI: 2.34, 1.53–3.59), a significantly fewer events of skin adverse effects (OR 95% CI: 0.27, 0.16–0.46) and nephrotoxicity (OR 95% CI: 0.45, 0.28–0.72) were recorded in linezolid. Based on the analysis of the pooled data of randomized control trials, linezolid should be a better choice for treatment of patients with S. aureus infections, especially in SSTIs patients than glycopeptides. However, when physicians choose to use linezolid, risk of haematological and gastrointestinal events should be taken into account according to the characteristics of the specific patient populations.

[Incidence of drug-induced thrombocytopenia in hospitalized patients]

OBJECTIVE

To find out the incidence of drug-induced thrombocytopenia and which medications are implicated, and to establish pharmaceutical activity for its prevention and resolution.

METHODS

A prospective study was conducted between June and December 2009 in hospitalized patients over 18 years of age with thrombocytopenia. The medications considered to be associated with thrombocytopenia were included in a database drawn up from the bibliography. In a suspected case, the doctor was recommended to discontinue, decrease the dosage or keep the drug under observation; and a follow-up of the patient's platelet count was made in order to classify the relationship between the drug and thrombocytopenia.

RESULTS

273 patients were included (61.5% men) with a mean age of 60 ± 15 years. Mean stay was 18 ± 17 days. TCP incidence was 2.26%. The services most involved were Haematology (56), Intensive Care Medicine (48) and Oncology (40). TCP was moderate in 69% of cases, mild in 26 % and severe in 5%. There were 8 cases of drug-induced thrombocytopenia (0.063% incidence), which were resolved in an average of 7.6 days. The medications related were enoxaparin (2), linezolid (2), tacrolimus (2), thymoglobulin (1) and heparin (1). The doctor was recommended to discontinue the drug (2), decrease the dosage (3) or keep it under observation (3), with 100% acceptance.

CONCLUSIONS

Pharmaceutical validation must incorporate an assessment of the platelet count, as it may contribute both to early identification of thrombocytopenia, and to following up platelet counts in patients receiving therapy with thrombocytopenia related drugs.

Safety of CETP inhibition

PURPOSE OF REVIEW

Cholesteryl ester transfer protein (CETP)-inhibiting drugs effectively raise HDL cholesterol. In 2007, the CETP inhibitor torcetrapib unexpectedly showed increased fatality and cardiovascular events, possibly related to increased blood pressure and aldosterone levels caused by torcetrapib. Since then, novel CETP inhibiting drugs have been investigated. This review will discuss the safety of the CETP-inhibiting drugs.

RECENT FINDINGS

The novel CETP inhibitors dalcetrapib, evacetrapib and anacetrapib did not show harmful effects on blood pressure or aldosterone levels. Ultrasound brachial artery flow-mediated vasodilation, carotid MRI and (18)F-fluordeoxyglucose PET imaging studies, showed that dalcetrapib therapy had neither harmful nor beneficial effects on endothelial function, atherosclerosis progression, or vessel wall inflammation. Recently, the clinical endpoint study investigating dalcetrapib was announced to be terminated early, after the second interim analysis showed that dalcetrapib lacked clinically meaningful efficacy.

SUMMARY

Dalcetrapib, evacetrapib and anacetrapib did not show the harmful effects on aldosterone and blood pressure that were exhibited by torcetrapib, indicating that CETP inhibition is well tolerated. So far CETP inhibition did not show beneficial effects on clinical outcome. The phase III study with anacetrapib will give final answers on whether CETP inhibition can reduce cardiovascular events.

Linezolid for treatment of chronic extensively drug-resistant tuberculosis

BACKGROUND

Linezolid has antimycobacterial activity in vitro and is increasingly used for patients with highly drug-resistant tuberculosis.

METHODS

We enrolled 41 patients who had sputum-culture-positive extensively drug-resistant (XDR) tuberculosis and who had not had a response to any available chemotherapeutic option during the previous 6 months. Patients were randomly assigned to linezolid therapy that started immediately or after 2 months, at a dose of 600 mg per day, without a change in their background regimen. The primary end point was the time to sputum-culture conversion on solid medium, with data censored 4 months after study entry. After confirmed sputum-smear conversion or 4 months (whichever came first), patients underwent a second randomization to continued linezolid therapy at a dose of 600 mg per day or 300 mg per day for at least an additional 18 months, with careful toxicity monitoring.

RESULTS

By 4 months, 15 of the 19 patients (79%) in the immediate-start group and 7 of the 20 (35%) in the delayed-start group had culture conversion (P=0.001). Most patients (34 of 39 [87%]) had a negative sputum culture within 6 months after linezolid had been added to their drug regimen. Of the 38 patients with exposure to linezolid, 31 (82%) had clinically significant adverse events that were possibly or probably related to linezolid, including 3 patients who discontinued therapy. Patients who received 300 mg per day after the second randomization had fewer adverse events than those who continued taking 600 mg per day. Thirteen patients completed therapy and have not had a relapse. Four cases of acquired resistance to linezolid have been observed.

CONCLUSIONS

Linezolid is effective at achieving culture conversion among patients with treatment-refractory XDR pulmonary tuberculosis, but patients must be monitored carefully for adverse events. (Funded by the National Institute of Allergy and Infectious Diseases and the Ministry of Health and Welfare, South Korea; ClinicalTrials.gov number, NCT00727844.).

Clinical efficacy of oral linezolid compared with intravenous vancomycin for the treatment of methicillin-resistant Staphylococcus aureus-complicated skin and soft tissue infections: a retrospective, propensity score-matched, case-control analysis

BACKGROUND

Linezolid is 100% bioavailable in oral and intravenous formulations. In a recent prospective, randomized, open-label, comparator-controlled, multicenter, phase 4 clinical trial in adults with complicated skin and soft tissue infections (cSSTIs) caused by methicillin-resistant Staphylococcus aureus (MRSA), linezolid achieved clinical and microbiologic success comparable to appropriately dosed intravenous vancomycin. Although patients were randomly assigned to receive linezolid or vancomycin, the protocol allowed patients to start therapy using oral or intravenous linezolid on the basis of investigator discretion and patient ability to tolerate oral medication.

OBJECTIVE

The objective of this study was to assess the efficacy and tolerability of linezolid when administered orally in adults with cSSTI caused by MRSA. In this retrospective analysis, we examined data collected from the aforementioned trial to compare outcomes in patients who received either oral linezolid or intravenous vancomycin therapy.

METHODS

This study analyzed outcomes in patients who received treatment for 7 to 14 days with either oral linezolid (600 mg q12h; n = 95) or intravenous vancomycin (15 mg/kg q12h, adjusted for creatinine clearance and trough concentration; n = 210). By design, these groups were not randomized. Propensity score matching on baseline variables was used to balance these groups by identifying a comparable group of patients who received vancomycin therapy and comparing them with patients who received oral linezolid therapy. Clinical and microbiologic success rates at the end of treatment and the end of the study (EOS) were then directly compared between the groups using matched-pair logistic regression. The tolerability of the 2 treatments (within this matched group) was also described.

RESULTS

Ninety-two patients with well-matched baseline characteristics were included in each treatment group. At EOS, the odds ratio for clinical success of oral linezolid therapy vs intravenous vancomycin therapy was 4.0 (95% CI, 1.3-12.0; P = 0.01), and the odds ratio for microbiologic success at EOS was 2.7 (95% CI, 1.2-5.7; P = 0.01). Overall rates of adverse events in each group were consistent with reported safety profiles for each drug.

CONCLUSION

A favorable clinical cure rate was achieved with oral linezolid therapy when compared with intravenous vancomycin therapy in propensity score-matched patients with cSSTI proved to be caused by MRSA. ClinicalTrials.gov Identifier: NCT00087490.

Safety and efficacy of linezolid in 16 infants and children in Japan

Linezolid, an oxazolidinone antibiotic, exhibits a broad spectrum of activity against Gram-positive bacteria. It has been licensed for adult use in Japan since 2006 for MRSA infections, and has also been used off-label for pediatric patients. At our university hospital, a total of 16 infants and children (including one non-Japanese Asian) were administered linezolid owing to infection with multidrug-resistant Gram-positive bacteria, after consent had been provided. All patients had severe underlying diseases or indications for surgery. Eighty-eight percent of the causal microorganisms were methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-resistant coagulase-negative Staphylococcus and all were sensitive to linezolid. Linezolid was administered because the antecedent anti-MRSA medications were ineffective or contraindicated, or intravenous-to-oral switch therapy was requested owing to cardiac or orthopedic surgical-site infections. The median duration of administration was 13 days (range 3-31 days). The overall efficacy was 91 % (10/11) in those for whom efficacy could be evaluated. Only two patients (both teen-aged) encountered linezolid-related adverse effects (13 %, 2/16). One patient showed elevation of liver enzymes (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), requiring that administration be withdrawn, but enzyme levels returned to normal after the patient had been switched to vancomycin. The other patient showed transiently decreased platelet counts. Linezolid is considered generally safe and effective for children in Japan, especially for those who cannot use other anti-MRSA medications or those who require oral antibiotics for infections with multidrug-resistant Gram-positive bacteria.

Randomized, double-blind, phase II, multicenter study evaluating the safety/tolerability and efficacy of JNJ-Q2, a novel fluoroquinolone, compared with linezolid for treatment of acute bacterial skin and skin structure infection

JNJ-Q2 is a fluoroquinolone with broad coverage including methicillin-resistant Staphylococcus aureus (MRSA). A double-blind, multicenter, phase II noninferiority study treated 161 patients for 7 to 14 days, testing the efficacy of JNJ-Q2 (250 mg, twice a day [BID]) versus linezolid (600 mg, BID) in patients with acute bacterial skin and skin structure infections (ABSSSI). The prespecified criterion for noninferiority was 15%. Primary intent-to-treat analysis was unable to declare noninferiority, as the risk difference lower bound of the 95% confidence interval between treatments was 19% at 36 to 84 h postrandomization for the composite end point of lesion assessment and temperature. Prespecified clinical cure rates 2 to 14 days after completion of therapy were similar (83.1% for JNJ-Q2 versus 82.1% for linezolid). Post hoc analyses revealed that JNJ-Q2 was statistically noninferior to linezolid (61.4% versus 57.7%, respectively; P = 0.024) based on the 2010 FDA guidance, which defines treatment success as lack of lesion spread and afebrile status within 48 to 72 h postrandomization. Despite evidence of systemic disease, <5% of patients presented with fever, suggesting fever is not a compelling surrogate measure of systemic disease resolution for this indication. Nausea and vomiting were the most common adverse events. Of the patients, 86% (104/121) had S. aureus isolated from the infection site; 63% of these were MRSA. The results suggest JNJ-Q2 shows promise as an effective treatment for ABSSSI, demonstrating (i) efficacy for early clinical response (i.e., lack of spread of lesions and absence of fever at 48 to 72 h), and (ii) cure rates for ABSSSI pathogens (especially MRSA) consistent with the historical literature.

Cholesteryl ester transfer protein inhibition to reduce cardiovascular risk: Where are we now?

Elevated low-density lipoprotein-cholesterol (LDL-C) and reduced high-density lipoprotein-cholesterol (HDL-C) are major risk factors for the development of cardiovascular disease. One approach to raising HDL-C is to inhibit the cholesteryl ester transfer protein (CETP), a plasma protein that promotes transfer of cholesteryl esters from HDL and other lipoprotein fractions. Drugs that inhibit CETP increase HDL-C and some lower LDL-C. However, the development of torcetrapib, the first CETP inhibitor to be tested in a human clinical outcomes trial, was terminated because it caused an excess of deaths and cardiovascular events. There is evidence, however, that torcetrapib had adverse off-target effects unrelated to CETP inhibition. This has opened the way for retesting of the hypothesis that CETP inhibitors will be anti-atherogenic in studies conducted with agents such as dalcetrapib and anacetrapib that do not share the off-target effects of torcetrapib. Clinical outcome trials with dalcetrapib and anacetrapib are currently under way.