Use of mefloquine in children - a review of dosage, pharmacokinetics and tolerability data

Currently available data provide a scientific basis for the use of mefloquine in small children in the chemoprophylaxis setting and as a part of treatment regimens for children living in endemic areas

Pregnancy and Fetal Outcomes After Exposure to Mefloquine in the Pre- and Periconception Period and During Pregnancy

Pregnant women who travel to malarious areas and their clinicians need data on the safety of malaria chemoprophylaxis. The drug safety database analysis of mefloquine exposure in pregnancy showed that the birth defect prevalence and fetal loss in maternal, prospectively-monitored cases were comparable to background rate

The position of mefloquine as a 21st century malaria chemoprophylaxis

BACKGROUND: Malaria chemoprophylaxis prevents the occurrence of the symptoms of malaria. Travellers to high-risk Plasmodium falciparum endemic areas need an effective chemoprophylaxis. METHODS: A literature search to update the status of mefloquine as a malaria chemoprophylaxis. RESULTS: Except for clearly defined regions with multi-drug resistance, mefloquine is effective against the blood stages of all human malaria species, including the recently recognized fifth species, Plasmodium knowlesi. New data were found in the literature on the tolerarability of mefloquine and the use of this medication by groups at high risk of malaria. DISCUSSION: Use of mefloquine for pregnant women in the second and third trimester is sanctioned by the WHO and some authorities (CDC) allow the use of mefloquine even in the first trimester. Inadvertent pregnancy while using mefloquine is not considered grounds for pregnancy termination. Mefloquine chemoprophylaxis is allowed during breast-feeding. Studies show that mefloquine is a good option for other high-risk groups, such as long-term travellers, VFR travellers and families with small children. Despite a negative media perception, large pharmaco-epidemiological studies have shown that serious adverse events are rare. A recent US evaluation of serious events (hospitalization data) found no association between mefloquine prescriptions and serious adverse events across a wide range of outcomes including mental disorders and diseases of the nervous system. As part of an in-depth analysis of mefloquine tolerability, a potential trend for increased propensity for neuropsychiatric adverse events in women was identified in a number of published clinical studies. This trend is corroborated by several cohort studies that identified female sex and low body weight as risk factors. CONCLUSION: The choice of anti-malarial drug should be an evidence-based decision that considers the profile of the individual traveller and the risk of malaria. Mefloquine is an important, first-line anti-malarial drug but it is crucial for prescribers to screen medical histories and inform mefloquine users of potential adverse events. Careful prescribing and observance of contraindications are essential. For some indications, there is currently no replacement for mefloquine available or in the pipeline

Eye disorders reported with the use of mefloquine (Lariam(®)) chemoprophylaxis--A drug safety database analysis

BACKGROUND Between 80 and 90 million travellers visit malaria endemic areas annually and many require malaria chemoprophylaxis. The characterization of the risk and nature of eye disorders occurring during the use of malaria chemoprophylaxis is relevant for travel medicine advisors. METHODS We did a database analysis on eye disorder adverse events reported for mefloquine (as Lariam®) using the F. Hoffmann-La Roche global drug safety database for the time frame February 1984 to January 18th, 2011. These adverse event reports were reviewed by a trained ophthalmologist. The analysis focused on 3 categories of eye disorders--Category 1: visual acuity; Category 2: anatomical parts of the eye and Category 3: neuro-ophthalmic events. To put our analysis in context, an extensive literature search on "mefloquine" and "eye disorders" was conducted. RESULTS A total of 591 cases with 695 events assigned to the "Eye disorder" SOC in individuals exposed to mefloquine chemoprophylaxis were reported. The highest proportion of events (n = 493, 70.9%) was in Category 1: visual acuity (mainly visual impairment and blurred vision), followed by Category 3: neuro-ophthalmic events (n = 124, 17.8%). The majority of visual adverse events were non-serious but 37.7% (n = 223) of cases were classified as serious. Nine events of maculopathy were reported and 48 cases with 53 events described symptoms of optic neuropathy. CONCLUSIONS Mefloquine, like other anti-malarials, may be associated with eye disorders. Prescribers of anti-malarials should inform travellers regarding the risk of potential ocular side effects. Users of chemoprophylaxis who experience visual disorders should be referred to an ophthalmologist

Comparative benefit of malaria chemoprophylaxis modelled in United Kingdom travellers

BACKGROUND: Chemoprophylaxis against falciparum malaria is recommended for travellers from non-endemic countries to malarious destinations, but debate continues on benefit, especially with regard to mefloquine. Quantification of benefit for travellers from the United Kingdom (UK) was modelled to assist clinical and public health decision making. METHODS: The model was constructed utilising: World Tourism Organization data showing total number of arrivals from the UK in countries with moderate or high malaria risk; data from a retrospective UK Clinical Practice Research Datalink (CPRD) drug utilisation study; additional information on chemoprophylaxis, case fatality and tolerability were derived from the travel medicine literature. Chemoprophylaxis with the following agents was considered: atovaquone-proguanil (AP), chloroquine with and without proguanil (C ± P), doxycycline (Dx), mefloquine (Mq). The model was validated for the most recent year with temporally matched datasets for UK travel destinations and imported malaria (2007) against UK Health Protection Agency data on imported malaria. RESULTS: The median (mean) duration of chemoprophylaxis for each agent in weeks (CPRD) was: AP 3.3 (3.5), C ± P 9 (12.1), Dx 8 (10.3), Mq 9 (12.3): the maximum duration of use of all regimens was 52 weeks. The model correctly predicted falciparum malaria deaths and gave a robust estimate of total cases - model: 5 deaths from 1118 cases; UK Health Protection Agency: 5 deaths from 1153 cases. The number needed to take chemoprophylaxis (NNP) to prevent a case of malaria considered against the 'background' reported incidence in non-users of chemoprophylaxis deemed in need of chemoprophylaxis was: C ± P 272, Dx 269, Mq 260, AP 252; the NNP to prevent a UK traveller malaria death was: C ± P 62613, Dx 61923, Mq 59973, AP 58059; increasing the 'background' rate by 50% yielded NNPs of: C ± P 176, Dx 175, Mq 171, AP 168. The impact of substituting atovaquone-proguanil for all mefloquine usage resulted in a 2.3% decrease in estimated infections. The number of travellers experiencing moderate adverse events (AE) or those requiring medical attention or drug withdrawal per case prevented is as follows: C ± P 170, Mq 146, Dx 114, AP 103. CONCLUSIONS: The model correctly predicted the number of malaria deaths, providing a robust and reliable estimate of the number of imported malaria cases in the UK, and giving a measure of benefit derived from chemoprophylaxis use against the likely adverse events generated. Overall numbers needed to prevent a malaria infection are comparable among the four options and are sensitive to changes in the background infection rates. Only a limited impact on the number of infections can be expected if Mq is substituted by AP

Antimalarial chemoprophylaxis and the risk of neuropsychiatric disorders

Case reports and epidemiological studies have associated the use of mefloquine with neuropsychiatric adverse events.; We used the General Practice Research Database to conduct a follow-up study with a nested case-control analysis. We assessed the risk of developing first-time anxiety, stress-related disorders/psychosis, depression, epilepsy or peripheral neuropathies in patients using mefloquine, chloroquine and/or proguanil, or atovaquone/proguanil for malaria chemoprophylaxis, as compared to unexposed travelers.; Compared to non-users of antimalarials, the adjusted odds ratio in the nested case-control analysis for users of mefloquine, chloroquine and/or proguanil, or atovaquone/proguanil were 0.71 (95% CI 0.56-0.90), 1.04 (95% CI 0.74-1.46), and 0.73 (95% CI 0.61-0.86) for anxiety or stress-related disorders combined, 0.54 (95% CI 0.41-0.71), 1.06 (95% CI 0.71-1.59), and 0.75 (95% CI 0.62-0.91) for depression, 0.69 (95% CI 0.35-1.36), 1.41 (95% CI 0.54-3.67), and 0.75 (95% CI 0.42-1.36) for epilepsy, and 1.22 (95% CI 0.50-2.99), 1.59 (95% CI 0.41-6.15), and 1.05 (95% CI 0.54-2.03) for neuropathies, respectively. The risk of all outcomes was higher in females than in males across all exposure categories.; The risk of neuropsychiatric disorders was similar for users and for non-users of anti-malarial chemoprophylaxis, with evidence for elevated risks in some subgroups

Use of anti-malarial drugs and the risk of developing eye disorders

Ocular toxicity was described in the late 1950s for some anti-malarial drugs, but only limited information is available on the comparison of ocular toxicity of different anti-malarials.; We conducted a follow-up study with a nested case-control analysis using the General Practice Research Database to compare the risk of developing a first-time diagnosis of an eye disorder during exposure of mefloquine, chloroquine and/or proguanil or atovaquone/proguanil use to non-users. We calculated incidence rates with 95% confidence intervals (CI) and odds ratios using multivariate conditional logistic regression analyses.; We included 83,148 patients and identified 652 cases with an incident eye disorder. The incidence rates with 95% CI of all eye disorders combined in users of mefloquine, chloroquine and/or proguanil, atovaquone/proguanil or travellers not using anti-malarials were 5.3 (4.3-6.5), 7.1 (5.0-9.9), 6.3 (5.6-7.2) and 5.1 (4.6-5.7), per 1000 person-years, respectively. As compared to non-users of anti-malarials, the adjusted odds ratio with 95% CI in the nested case-control analysis for users of mefloquine, chloroquine and/or proguanil, or atovaquone/proguanil were 1.33 (1.01-1.75), 1.61 (1.06-2.45), and 1.25 (1.03-1.52), respectively.; The study provides evidence that there was an increased risk of eye disorders in users of all anti-malarials compared to non-users of anti-malarials