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Neil S Roskell,1 Antonio Anzueto,2 Alan Hamilton,3 Bernd Disse,4 Karin Becker5 1Statistics, Bresmed Health Solutions Ltd, Sheffield, UK; 2School of Medicine, University of Texas Health Science Center, San Antonio, TX, USA; 3Medical Department, Boehringer Ingelheim (Canada) Ltd, Burlington, ON, Canada; 4Medical Department, Boehringer Ingelheim GmbH, Ingelheim am Rhein, Germany; 5Global Health Economics and Outcomes Research, Boehringer Ingelheim GmbH, Ingelheim am Rhein, Germany Purpose: In the absence of head-to-head clinical trials comparing the once-daily, long-acting beta2-agonists olodaterol and indacaterol for the treatment of chronic obstructive pulmonary disease (COPD), an indirect treatment comparison by systematic review and synthesis of the available clinical evidence was conducted. Methods: A systematic literature review of randomized, controlled clinical trials in patients with COPD was performed to evaluate the efficacy and safety of olodaterol and indacaterol. Network meta-analysis and adjusted indirect comparison methods were employed to evaluate treatment efficacy, using outcomes based on trough forced expiratory volume in 1 second (FEV1), Transition Dyspnea Index, St George’s Respiratory Questionnaire total score and response, rescue medication use, and proportion of patients with exacerbations. Results: Eighteen trials were identified for meta-analysis (eight, olodaterol; ten, indacaterol). Olodaterol trials included patients of all severities, whilst indacaterol trials excluded patients with very severe COPD. Concomitant maintenance bronchodilator use was allowed in most olodaterol trials, but not in indacaterol trials. When similarly designed trials/data were analyzed for change from baseline in trough FEV1 (liters), the following mean differences (95% confidence interval) were observed: trials excluding concomitant bronchodilator: indacaterol 75 mcg versus olodaterol 5 mcg, –0.005 (–0.077 to 0.067), and indacaterol 150 mcg versus olodaterol 5 mcg, 0.020 (–0.036 to 0.077); trials with concomitant tiotropium: indacaterol 150 mcg versus olodaterol 5 mcg, 0.000 (–0.043 to 0.042). In sensitivity analyses of the full network, results for change from baseline in trough FEV1 favored indacaterol, but this dataset suffered from trial design heterogeneity. For the other endpoints investigated, no statistically significant differences were found when analyzed in the full network. Conclusion: When compared under similar trial conditions, olodaterol and indacaterol have similar efficacy in patients with COPD. This research highlights the importance of considering the concomitant COPD medication when evaluating treatment effects in COPD. Keywords: COPD, olodaterol, indacaterol, meta-analysis, systematic review, LABA

Abstract Objectives: Previous systematic reviews and meta-analyses of treatments in relapsing-remitting multiple sclerosis (RRMS) derived their findings from either placebo-controlled studies only or separately from head-to-head and comparative studies. The purpose of this study is to compare annualized relapse rates (ARR) of fingolimod versus all of the commonly used first-line treatments in RRMS using evidence from both placebo-controlled and head-to-head studies. In absence of the head-to-head data between fingolimod and the other treatments, these comparisons were formed using meta-analysis techniques for indirect treatment comparisons. Methods: A systematic literature review was conducted by searching MEDLINE, EMBASE, and the Cochrane Library with no limitations applied on publication language or dates. Included studies were randomized controlled trials evaluating one or more of fingolimod, interferon beta-1a, interferon beta-1b, or glatiramer acetate in RRMS populations. Primary outcome was ARR. Data extraction included author, year, treatment, dosage, mean age, percentage females, duration of disease, Expanded Disability Status Scale (EDSS) score at baseline, relapses in 2 years prior to baseline, trial duration, relapse-related outcome, and definition of relapse. The indirect treatment comparisons were performed using a mixed-treatment comparison framework. ARR was analyzed as a Poisson outcome. Results: The relative ARRs, for each treatment versus fingolimod, estimated from our meta-analyses were 1.43 (glatiramer acetate 20 mg), 1.51 (interferon beta-1b 250 mcg), 1.55 (interferon beta-1a 44 mcg), 1.67 (interferon beta-1a 22 mcg), 1.93 (interferon beta-1a 30 mcg), and 2.32 (placebo). None of the 95% confidence intervals for these estimates overlapped unity, implying statistical significance of these findings. Limitations: The key limitations of this study are the persisting heterogeneity even after adjusting for covariates and the variability in outcome definition across the included trials. Conclusions: Our study demonstrated that fingolimod significantly reduces relapse frequency in patients with RRMS compared with current first-line disease-modifying therapies. [ABSTRACT FROM AUTHOR]

Background: Chloroquine plus proguanil is widely used for malaria chemoprophylaxis despite low effectiveness in areas where multidrug-resistant malaria occurs. Studies have shown that atovaquone and proguanil hydrochloride is safe and effective for prevention of falciparum malaria in lifelong residents of malaria-endemic countries, but little is known about non-immune travellers.Methods: In a double-blind equivalence trial, 1083 participants travelling to a malaria-endemic area were randomly assigned to two treatment groups: atovaquone-proguanil plus placebos for chloroquine and proguanil, or chloroquine, proguanil, and placebo for atovaquone-proguanil. Follow-up was by telephone 7 and 60 days after travel and at a clinic at 28 days. Serum samples were tested for antibodies to a malaria circumsporozoite protein. Blood and serum samples of participants with a potential malaria diagnosis were tested in a reference laboratory.Findings: 7 days after travel, at least one adverse event was reported by 311 (61%) of 511 participants who received atovaquone-proguanil and 329 (64%) of 511 who received chloroquine-proguanil. People receiving atovaquone-proguanil had a lower frequency of treatment-related gastrointestinal adverse events (59 [12%] vs 100 [20%], p=0.001), and of treatment-related adverse events of moderate or severe intensity (37 [7%] vs 56 [11%], p=0.05). There were fewer treatment-related adverse events that caused prophylaxis to be discontinued in the atovaquone-proguanil group than in the chloroquine-proguanil group (one [0.2%] vs ten [2%], p=0.015).Interpretation: Overall the two preparations were similarly tolerated. However, significantly fewer adverse gastrointestinal events were observed in the atovaquone-proguanil group in than in the chloroquine-proguanil group. [ABSTRACT FROM AUTHOR]

Background: Brexanolone injection, the first therapy approved by the US FDA for the treatment of postpartum depression (PPD) in adults, has been shown to produce a significantly greater decrease in the Hamilton Rating Scale for Depression (HAM-D) total score than placebo in randomised controlled trials (RCTs) of women with PPD., Objectives: Given the rapid effect of brexanolone injection (within 60 h) sustained throughout the length of the trials (30 days), we sought to compare its efficacy data against selective serotonin reuptake inhibitors (SSRIs), the class of antidepressants most commonly prescribed for PPD, using HAM-D and Edinburgh Postnatal Depression Scale (EPDS) outcomes from currently available RCTs., Methods: We extracted data from 26 studies identified in a systematic literature review of pharmacological and pharmacological/nonpharmacological combination therapies in PPD. Six studies were suitable to form evidence networks through which to perform indirect treatment comparisons (ITCs) of HAM-D and EPDS outcomes between brexanolone and SSRIs. Having assessed the comparability and suitability of the available evidence for analysis, we discovered significant heterogeneity in the study designs, most notably in the placebo arms of the trials. We therefore conducted matching-adjusted indirect comparisons (MAICs) between brexanolone and the placebo arms of comparator studies, subsequently using the MAIC results of brexanolone versus placebo, and results for SSRIs versus placebo, to form ITCs of brexanolone versus SSRIs at three separate time points-day 3, week 4 and last observation. ITCs were calculated as the differences in change from baseline (CFB) in HAM-D and, separately, CFB in EPDS, between treatments, and reported with 95% confidence intervals (CIs)., Results: For all time points, MAICs showed larger differences in CFB for brexanolone compared with SSRIs. Differences (95% CIs) between brexanolone and SSRIs were 12.79 (8.04-17.53) [day 3], 5.87 (- 1.62 to 13.37) [week 4] and 0.97 (- 6.35 to 8.30) [last observation] for the HAM-D. For the EPDS, the differences in CFB were 7.98 (5.32-10.64) [day 3], 6.35 (3.13-9.57) [week 4] and 4.05 (0.79-7.31) [last observation]. Other analytical approaches are also presented to demonstrate the similarity of results, using a network meta-analysis approach, and the importance of using the MAIC method to control for the important heterogeneity between placebo arms., Conclusions: Acknowledging the limitations of ITCs and this evidence base, when compared with SSRIs, these analyses suggest that brexanolone demonstrated larger differences in CFB for both patient- and clinician-reported PPD outcomes and at all investigated time points after adjusting for differences between placebos in the included studies.

Objective: Systematically review and synthesize the clinical evidence of treatments for attention deficit hyperactivity disorder (ADHD) by indirectly comparing established treatments in the UK with a drug recently approved in Europe (lisdexamfetamine [LDX])., Population: children and adolescents., Setting: Europe. Comparators: methylphenidate (MPH), atomoxetine (ATX), and dexamphetamine (DEX). Electronic databases and relevant conference proceedings were searched for randomized, controlled clinical trials evaluating efficacy and safety of at least one of the comparators and LDX. Quality assessments for each included trial were performed using criteria recommended by the Centre for Reviews and Dissemination. Network meta-analysis methods for dichotomous outcomes were employed to evaluate treatment efficacy., Main Outcome Measures: Response, as defined by either a reduction from baseline of at least 25% in the ADHD Rating Scale [ADHD-RS] total score or, separately, as assessed on the Clinical Global Impression-Improvement [CGI-I] scale, and safety (all-cause withdrawals and withdrawal due to adverse events)., Results: The systematic review found 32 trials for the meta-analysis, including data on LDX, ATX, and different formulations of MPH. No trials for DEX meeting the inclusion criteria were found. Sufficient data were identified for each outcome: ADHD-RS, 16 trials; CGI-I, 20 trials; all-cause withdrawals, 28 trials; and withdrawals due to adverse events, 27 trials. The relative probability of treatment response for CGI-I (95% confidence intervals [CI]) for ATX versus LDX was 0.65 (0.53-0.78); for long-acting MPH versus LDX, 0.82 (0.69-0.97); for intermediate release MPH versus LDX, 0.51 (0.40-0.65); and for short-acting MPH versus LDX, 0.62 (0.51-0.76). The relative probabilities of ADHD-RS treatment response also favored LDX., Conclusions: For the treatment of ADHD, the synthesis of efficacy data showed statistically significant better probabilities of response with LDX than for formulations of MPH or ATX. The analysis of safety data proved inconclusive due to low event rates. These results may be limited by the studies included, which only investigated the short-term efficacy of medications in patients without comorbid disorders.

Aims: Clinical trials have shown that anticoagulation with vitamin K antagonists (VKAs), e.g. warfarin, decreases the risk of stroke in patients with atrial fibrillation (AF); however, increased bleeding risk is one of the safety concerns. The primary objective was to conduct a systematic review of the published literature, assessing the risk of major bleeding and mortality in patients with AF treated with VKAs., Methods and Results: Online searches of MEDLINE, EMBASE, BIOSIS, and the Cochrane Library were performed to a pre-specified protocol from 1960 to March 2012 for randomized controlled trials (RCTs) and from January 1990 to March 2012 for observational studies. A total of 47 studies (16 RCTs and 31 observational studies) were included. Cumulative follow-up was 61,563 patient-years for RCTs and 484 241 patient-years for observational studies. The overall median incidence of major bleeding was 2.1 per 100 patient-years (range, 0.9-3.4 per 100 patient-years) for RCTs and 2.0 per 100 patient-years (range, 0.2-7.6 per 100 patient-years) for observational studies. With study year as a proxy for changing management patterns, some evidence of bleeding rates and/or their reporting increasing over time was noted. Mortality rates from observational studies were inadequately reported to allow comparison with those from RCT data., Conclusion: The median rate of major bleeding in observational studies and RCTs is similar. The larger heterogeneity in bleeding rates observed in a real-life setting could reflect a high variability in standard of care of patients on VKAs and/or methodological differences between observational studies and/or variability in data sources.

Objective: This meta-analysis compared efficacy (pain response) of drugs that are licensed or commonly used in the treatment of fibromyalgia. A meta-analysis of safety measured via discontinuation because of adverse events was also performed., Methods: We conducted a meta-analysis of 21 clinical trials to estimate treatment differences vs. placebo, separately, for duloxetine, fluoxetine, gabapentin, milnacipran, pramipexole, pregabalin, either of two tricyclic antidepressants, and tramadol plus paracetamol. Indirect treatment comparisons using mixed treatment comparisons methodology were conducted for all pairwise comparisons. Pain response was analyzed as improvement of at least 30%, and separately of 50%, from baseline., Results: When compared with placebo, statistically significant pain responses (improvement of 30% and 50%) were observed for patients treated with duloxetine, milnacipran 200 mg/day, pregabalin 300 or 450 mg/day, and tramadol plus paracetamol. Treatment with fluoxetine, gabapentin, or milnacipran 100 mg/day resulted in significant findings for the 30% improvement in pain response. The meta-analysis showed a statistically increased risk of discontinuation because of adverse events for milnacipran 100 and 200 mg/day (both P < 0.001), and pregabalin 300 and 450 mg/day (P = 0.009 and P < 0.001, respectively). All other treatments, except fluoxetine, showed numerically increased risk over placebo for discontinuation because of adverse events. In the indirect comparisons, no pairwise comparison of active treatments reached statistical significance for either pain response end point., Conclusion: All eight active treatments displayed evidence suggesting improvement over placebo in the treatment of pain in patients suffering from fibromyalgia. Indirect comparison of active treatments found no strong differences., (© 2011 RTI Health Solutions. Pain Practice © 2011 World Institute of Pain.)

Aims: To report the persistence of glaucoma medical therapy in a database of 1006 patients with ocular hypertension (OHT), normal tension glaucoma (NTG) and primary open-angle glaucoma (POAG) attending the Glaucoma Clinic at Glasgow Royal Infirmary, Glasgow, UK., Method: Analyses have been carried out using specially written queries to generate reports relating to initial treatment choice and persistence for individual drugs. Queries were investigated in the database time period from 16 February 1982 to 11 February 2009. When investigating drug persistence, the results from the database were split into two distinct time periods from 1997 to 2001 and from 2002 to 2009 to reflect the available treatment options used., Results: The number of patients with each diagnosis was as follows: POAG 608; OHT 246; NTG 152. The Kaplan-Meier estimate for mean persistence from 1997 to 2001 (time to treatment discontinuation) of latanoprost was 58.8 ± 1.95 months, timolol was 41.8 ± 3.94 months, brimonidine was 24.1 ± 3.05 months, and betaxolol was 22.9 ± 2.04 months. The Kaplan-Meier estimate for mean persistence from 2002 to 2009 of latanoprost (time to treatment discontinuation) was 52.0 ± 2.26 months, bimatoprost was 25.8 ± 2.89 months, and travoprost was 23.0 ± 1.27 months. The Kaplan-Meier estimate for mean persistence of latanoprost (time to treatment change) was 37.5 ± 2.47 months, travoprost was 30.2 ± 2.70 months, and bimatoprost was 17.5 ± 2.88 months., Conclusion: The introduction of the first prostaglandin analogue, latanoprost, dramatically improved treatment persistence for glaucoma patients. In the current prostaglandin-rich treatment environment, these data do not show any significant differences between prostaglandins with respect to treatment persistence.

Patients with atrial fibrillation at moderate to high risk of stroke are not always anticoagulated despite a lack of contraindications to vitamin K antagonists (VKAs) like warfarin. These patients are treated with aspirin, aspirin-clopidogrel combination therapy or even receive no thromboprophylaxis. The oral direct thrombin inhibitor, dabigatran etexilate 150 mg BID and 110 mg BID, might represent an alternative for these patients; however, no head-to-head clinical trial data exist versus these alternative treatments. A network meta-analysis (NMA) was performed to indirectly compare dabigatran etexilate with antiplatelets and placebo. Compared with placebo, dabigatran etexilate 150 mg BID was estimated to significantly reduce the risk of any stroke (ischaemic and haemorrhagic) by 75% (relative risk [RR] 0.25; 95% confidence interval [CI] 0.12-0.51), ischaemic stroke by 77% (RR 0.23; 95% CI 0.14-0.38), systemic embolism by 83% (RR 0.17; 95% CI 0.05-0.50) and mortality by 36% (RR 0.64; 95% CI 0.45-0.91). Dabigatran etexilate 150 mg BID was estimated to significantly reduce the risk of any stroke compared with aspirin monotherapy by 63% (RR 0.37; 95% CI 0.20-0.69) and aspirin plus clopidogrel by 61% (RR 0.39; 95% CI 0.21-0.72). Trends toward reduced risk with both dabigatran etexilate regimens were found for most clinical outcomes. Relative risk estimates of dabigatran etexilate versus adjusted-dose VKAs within the NMA were consistent with results from the head-to-head randomised trial of these two strategies. Indirect evidence suggests treatment with dabigatran etexilate offers benefit for the prevention of stroke, systemic embolism and mortality over antiplatelets and placebo. There was no indication of increased intracranial or extracranial haemorrhage with dabigatran etexilate compared to antiplatelet agents.

Oral dabigatran etexilate is indicated for the prevention of venous thromboembolism (VTE) in patients undergoing total knee replacement or total hip replacement. We investigated the cost-effectiveness of the 150 mg once daily (od) dose recommended for patients aged over 75 or with moderate renal impairment, from a United Kingdom National Health Service perspective. Dabigatran etexilate was compared with subcutaneous enoxaparin 40 mg od, using a decision model. Risks for VTE and bleeding were derived from subgroup analyses of the phase III trials. Dabigatran etexilate was less costly than enoxaparin; cost savings varied from pound62 to pound274 (base-case analyses) and were primarily due to differences in administration costs. Results were robust across a range of sensitivity analyses. Dabigatran etexilate 150 mg od is cost saving compared with enoxaparin 40 mg od in patients aged over 75years and in patients with moderate renal impairment, with comparable efficacy and safety.

Dabigatran etexilate has been investigated in three phase III trials for the prevention of venous thromboembolism (VTE). Health technology assessment agencies increasingly require meta-analyses of all relevant evidence for an intervention, if appropriate. The objective of this study was to perform a meta-analysis of efficacy and safety data for the recommended dose of dabigatran etexilate, 220 mg once daily (od), for VTE prophylaxis after total knee arthroplasty (TKA) and total hip arthroplasty (THA), and discuss the appropriateness of combining the data. Risk ratios (RR) for VTE and bleed end-points were estimated using fixed and random effects meta-analysis. Analyses were performed combining RE-MODEL and RE-NOVATE, which compared dabigatran etexilate with enoxaparin 40 mg od after TKA and THA, respectively, and also including RE-MOBILIZE, which compared dabigatran etexilate with enoxaparin 30 mg twice daily after TKA. Tests for statistical heterogeneity were performed using the Chi-squared statistic. No significant differences were detected between dabigatran etexilate and enoxaparin in any of the end-points analysed, either in the two trial analysis (all p > 0.15), or when all three trials were combined ( all p > 0.30). RRs (random effects) for the composite end-point total VTE and all-cause mortality were 0.95 [95% confidence intervals 0.82 - 1.10] and 1.05 [0.87 - 1.26] in the two and three trial analyses, respectively. Meta-analysis of RE-MODEL and RE-NOVATE supported the conclusions of the individual trials that dabigatran etexilate is non-inferior to enoxaparin 40 mg od, with a similar safety profile. Meta-analysis of all three trials found no significant differences between treatments in any of the end-points analysed. Heterogeneity between the trials cannot be ruled out.

Objective: This was an evaluation of the cost-effectiveness of oral dabigatran etexilate compared with subcutaneous low-molecular-weight heparin (enoxaparin) for the prevention of venous thromboembolism (VTE) after total knee replacement (TKR) and total hip replacement (THR) surgery from the perspective of the UK National Health Service., Methods: Dabigatran etexilate (220 mg once daily) was compared with enoxaparin (40 mg once daily) in patients undergoing TKR (duration of prophylaxis, 6-10 days) and THR (duration of prophylaxis, 28-35 days). The 10-week acute postsurgical phase was modeled using a decision tree. A Markov process (1-year cycle length) was used to model long-term events (recurrent VTE, postthrombotic syndrome, and consequences of intracranial hemorrhage) for patients' remaining lifetimes. Relative risks for VTE and bleeding events were derived from 2 Phase III studies that compared dabigatran etexilate with enoxaparin 40 mg once daily. The probabilities of long-term events were estimated using data from published longitudinal studies., Results: Rates of VTE and bleeding events did not differ significantly between dabigatran etexilate and enoxaparin. Dabigatran etexilate was less costly than enoxaparin in TKR and substantially less costly in THR, primarily due to differences in administration costs. The cost of prophylaxis for THR patients, including drugs and administration costs, was estimated at pound 137 for dabigatran etexilate and pound 237 for enoxaparin ( pound 7 for nursing time during the hospital stay, pound 91 for nurse home visits for administration after hospital discharge, and an additional pound 2 in drug costs). At a willingness-to-pay threshold of pound 20,000 per quality-adjusted life-year, the probability of cost-effectiveness for dabigatran etexilate was 75% in TKR and 97% in THR. These results were robust across a range of sensitivity analyses., Conclusion: From the perspective of the UK National Health Service, thromboprophylaxis with dabigatran etexilate was cost-saving compared with enoxaparin 40 mg once daily, with comparable efficacy and safety profiles.

Atovaquone-proguanil has been shown to be effective and well tolerated for malaria prophylaxis in residents of countries of endemicity and in nonimmune adult travelers, but data about traveling children are limited. In a randomized, open-label, multicenter prophylaxis trial, 221 nonimmune pediatric travelers (age, 2-17 years) received either atovaquone-proguanil or chloroquine-proguanil. Safety and clinical outcome were evaluated 7, 28, and 60 days after travel. By posttravel day 7, a total of 39 (35%) of 110 atovaquone-proguanil and 41 (37%) of 111 chloroquine-proguanil recipients reported > or =1 adverse event. The data indicate that, over the course of treatment, fewer atovaquone-proguanil recipients had treatment-related adverse events (8% vs. 14%), including gastrointestinal complaints (5% vs. 10%). Two subjects discontinued prophylaxis because of drug-related adverse events; both had received chloroquine-proguanil. Observed compliance with prophylaxis was similar before and during travel, but it was higher for atovaquone-proguanil in the posttravel period. No study participant developed malaria. Atovaquone-proguanil was well tolerated and is an important addition to the limited arsenal of prophylactic agents available to children.

Concerns about the tolerability of mefloquine highlight the need for new drugs to prevent malaria. Atovaquone-proguanil (Malarone; GlaxoSmithKline) was safe and effective for prevention of falciparum malaria in lifelong residents of malaria-endemic countries, but experience in nonimmune people is limited. In a randomized, double-blind study, nonimmune travelers received malaria prophylaxis with atovaquone-proguanil (493 subjects) or mefloquine (483 subjects). Information about adverse events (AEs) and potential episodes of malaria was obtained 7, 28, and 60 days after travel. AEs were reported by an equivalent proportion of subjects who had received atovaquone-proguanil or mefloquine (71.4% versus 67.3%; difference, 4.1%; 95% confidence interval, -1.71 to 9.9). Subjects who received atovaquone-proguanil had fewer treatment-related neuropsychiatric AEs (14% versus 29%; P=.001), fewer AEs of moderate or severe intensity (10% versus 19%; P=.001), and fewer AEs that caused prophylaxis to be discontinued (1.2% versus 5.0%; P=.001), compared with subjects who received melfoquine. No confirmed diagnoses of malaria occurred in either group. Atovaquone-proguanil was better tolerated than was mefloquine, and it was similarly effective for malaria prophylaxis in nonimmune travelers.

We conducted a double-blind, placebo-controlled, parallel, dose-escalation trial to evaluate the pharmacokinetics and safety of single, oral doses of amprenavir (141W94; formerly VX-478), a potent inhibitor of human immunodeficiency virus (HIV) type 1 protease, administered as hard gelatin capsules in 12 HIV-infected subjects. The doses of amprenavir evaluated were 150, 300, 600, 900, and 1,200 mg. Amprenavir was rapidly absorbed, with the time to maximum concentration occurring within 1 to 2 h after dosing. On the basis of power model analysis, the increase in the maximum concentration of amprenavir in plasma (Cmax) was less than dose proportional, and the increase in the area under the concentration-time curve from time zero to infinity (AUC0-infinity) was greater than dose proportional; mean slopes (with 90% confidence intervals) were 1.25 (1.16 to 1.35) and 0.78 (0.78 to 0.86) for AUC0-infinity and Cmax, respectively. Amprenavir was eliminated slowly, with a terminal-phase half-life of 8 h. A second study was conducted to determine the bioavailability of the hard gelatin capsule relative to that of a subsequently developed soft gelatin capsule. The capsules were bioequivalent in terms of AUC0-infinity but not in terms of Cmax; geometric-least-squares means ratios (with 90% confidence intervals) were 1.03 (0.92 to 1.14) and 1.25 (1.03 to 1. 53) for AUC0-infinity and Cmax, respectively. Administration of soft gelatin capsules of amprenavir with a high-fat breakfast resulted in a 14% decrease in the mean AUC0-infinity (from 9.58 to 8.26 microg. h/ml), which is not likely to be clinically significant. The most common adverse events related to amprenavir were headache, nausea, and hypesthesia. Amprenavir appears to be safe and well tolerated over the dose range of 150 to 1200 mg. On the basis of the present single-dose studies, amprenavir is an HIV protease inhibitor with favorable absorption and clearance pharmacokinetics that are only minimally affected by administration with food.

The objective of this study was to determine the safety and efficacy of atovaquone and proguanil hydrochloride combination therapy for the prophylaxis of Plasmodium falciparum malaria in at-risk nonimmune subjects in South Africa. This open-label trial was conducted at research sites in South Africa during the main malaria transmission season, February through July. The study volunteers were temporarily living in, or traveling to, a malaria-endemic area. They received I tablet of 250 mg atovaquone and 100 mg proguanil hydrochloride once daily for up to 10 weeks. Subjects were monitored using sequential clinical and laboratory assessments. Thick blood smears were stained and evaluated by a central laboratory. An immunochromatographic test for P. falciparum was also used for on-site patient management. Prophylactic success was summarized using a 95% confidence interval for the proportion of subjects who did not develop parasitemia or who withdrew due to a treatment-related adverse event. A total of 175 subjects (15% women) were enrolled in the trial. The mean duration of drug exposure was 8.9 weeks. The combination of atovaquone and proguanil hydrochloride was well tolerated. The most frequently reported adverse events considered possibly related to study treatment were headache (7%), abdominal pain (2%), increased cough (2%), and skin disorder (2%). No serious adverse events were reported, and no treatment-emergent effects were noted for any laboratory variables. One subject who was noncompliant with therapy developed parasitemia, and 3 subjects withdrew due to a treatment-related adverse event (2 subjects with headache and 1 with nausea and dizziness). The prophylaxis success rate was 97%. In this study, atovaquone and proguanil hydrochloride combination therapy had an excellent safety and efficacy profile for prophylaxis of P. falciparum malaria in nonimmune subjects.

Malaria poses a major health risk to people who are exposed to infection in malaria-endemic areas. A randomized, double-blind, placebo-controlled study was conducted to determine the efficacy and safety of Malarone (250 mg of atovaquone/100 mg of proguanil hydrochloride per tablet) for the chemoprophylaxis of Plasmodium falciparum malaria in Zambia. Adult volunteers received a three-day treatment course of Malarone to eliminate pre-existing parasitemia and were then immediately randomized to treatment with either one Malarone tablet daily (n = 136), or one placebo tablet daily (n = 138) for at least 10 weeks. Malaria blood smears were prepared on a weekly basis and a failure of chemoprophylaxis was defined as any subject who had a positive blood smear, or who withdrew from the study due to a treatment-related adverse event. The prophylaxis success rates in the Malarone and placebo groups were 98% and 63%, respectively (P < 0.001). The most commonly reported adverse events with at least a possible causal relationship to study medication were headache and abdominal pain, which occurred with a higher incidence in the placebo group. No subjects were withdrawn from the study due to a treatment-related adverse event. Thus, Malarone appears to have an excellent safety and efficacy profile for the chemoprophylaxis of P. falciparum infection.