Pregnancy and fetal outcomes after exposure to mefloquine in the pre- and periconception period and during pregnancy.

BACKGROUND: Pregnant women who travel to malarious areas and their clinicians need data on the safety of malaria chemoprophylaxis. METHODS: The effect of exposure to mefloquine on pregnancy and offspring outcomes was evaluated using the F. Hoffmann-La Roche global drug safety database for the time frame 31 January 1986 through 26 October 2010. We investigated pregnancy and fetal outcomes in maternal, paternal, and both-parent exposure cases with a focus on congenital malformations and fetal loss. The main outcome measures were birth defect prevalence and types of malformations. RESULTS: A total of 2506 cases of mefloquine exposure during pregnancy or in the pre- and periconception period were evaluated. Most cases were maternal prospective (outcome of the pregnancy unknown at the time of reporting; n = 2246 [89.6%]) followed by maternal retrospective cases (outcome of the pregnancy known at the time of reporting; n = 227 [9.0%]), with small numbers of paternal and both-parent exposure cases. Of the total 2246 mefloquine maternal prospective exposures (95.2%), 2139 occurred before conception and/or during the first trimester. Of 1383 maternal prospective cases with known outcome, 978 (70.7%) resulted in delivery, 405 (29.3%) resulted in abortion (112 spontaneous, 293 therapeutic), and 43 resulted in birth defects, corresponding to a birth defect prevalence of 4.39% (43 of 978). Prospective cases overall showed no specific pattern of birth malformations. CONCLUSIONS: 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 rates.

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

BACKGROUND: Use of anti-malarial medication in children is hampered by a paucity of dosage, pharmacokinetic and tolerability data. METHODS: Data on the use of mefloquine in children, particularly in young children weighing less than 20 kg, were reviewed using PubMed literature and reports on file. RESULTS: Chemoprophylaxis data: Two studies with a total of 170 children were found. A simulated mefloquine plasma profile showed that doses to achieve protective chemoprophylaxis blood concentration of mefloquine of approximately 620 ng/mL (or 1.67 µmol/L) in children should be at least 5 mg/kg. This simulated plasma profile in children corresponds to that seen in adult travellers using a weekly prophylaxis dose of 250 mg. This reinforces current practice of using weight-based dosage for children. Clearance per body weight is higher in older children. For children who travel to malaria risk areas tablets can be broken and crushed as required. It is necessary to disguise the bitter taste of the drug. Treatment data: Mefloquine treatment (alone or in combination) data are available for more than 6000 children of all age and weight categories. The stereoselectivity and pharmacokinetic profile of mefloquine in children is similar to that observed in adults. There is higher clearance in older children (aged 5-12 years) compared to younger children (aged 6-24 months). Mefloquine treatment is well tolerated in infants (5-12 kg) but vomiting is a problem at high doses. This led to the use of a "split dose" regimen with 15 mg/kg initially, followed 12 hours later by 10 mg/kg. Mefloquine 125 mg has been used as intermittent preventive treatment (IPT) and was found to be efficacious in reducing episodes of malaria in a moderate-transmission setting but vomiting was a problem in 8% of children aged 2-11 months. Mefloquine is also used as a component of artemisinin combination therapy (ACT) in small children. The combination artesunate plus mefloquine is a WHO approved first-line treatment for uncomplicated malaria in Africa. CONCLUSION: 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.

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 tolerability 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.

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

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Antimalarial chemoprophylaxis and the risk of neuropsychiatric disorders.

BACKGROUND: Case reports and epidemiological studies have associated the use of mefloquine with neuropsychiatric adverse events. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.