Hi JB,
I believe that the drug you mention is the antimalarial "mefloquine" (e.g., Lariam, Mefliam).
This drug has a broad array of adverse reactions, and some of the neuropsychiatric ones are quite striking. The numbers obviously vary depending upon the study/source. One published work reports an incidence of serious neurological/neuropsychiatric side effects of one in 215 in those being treated for malaria with mefloquine, but only one in 13,000 in persons taking the medication for malaria prevention/prophylaxis. Concerning seizures specifically, on balance the incidence is low enough that describing them as "a well known and relatively common adverse event" is arguably exaggerated.
Mefloquine unarguably does, however, reduce seizure threshold, as do certain other antimalarials, and may have convulsant properties.
Response to this inquiry is impeded by some important missing information, including:
1. How long ago was the seizure?
2. Did the seizure occur during the actual treatment of malaria or during malaria chemoprophylaxis?
3. Was a neurological examination undertaken, including an EEG and did the EEG involve provocative techniques/inductions? If so, what were the findings?
4. Has mefloquine been taken subsequently without untoward event?
5. Did the individual have any medical conditions or was he taking other medication (e.g., an antidepressant or tranquilizer) that may have contributed to seizure activity?
6. Did other potential contributing factors exist, e.g., fever, sleep deprivation, alcohol use.
About 10% of the general population will have a single seizure during their lifetime, often associated with an illness causing a high fever. A single seizure occurring in an individual without a fever would be anticipated in about 2% of the general population. Do those affected have reduced seizure thresholds? Probably, but it remains uncertain without appropriate neurological evaluation. And even then it often remains uncertain.
Does the fact that an individual, while taking mefloquine, experiences a single seizure mean that he has a lowered seizure threshold? When a convulsion occurs that seems related to mefloquine use, it could be a consequence of the drug's properties on an entirely healthy brain or on brain tissue that is predisposed to the propagation of abnormal electrical activity, e.g., scar tissue. The rest of the answer is as immediately above.
Of more interest is the finding that an adult with a single seizure has a 30-40% chance of having another at some point in the future.
Were a diver with a such a history to continue SCUBA, it surely would be prudent to keep pp02 to the lowest feasible level.
Helpful?
DocVikingo
This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual, and should not be construed as such.
