Mefloquine Stats & Data

Boxed/major warnings emphasize that psychiatric symptoms (e.g., acute anxiety, depression, restlessness) or neurologic/vestibular symptoms (e.g., dizziness, loss of balance, tinnitus) can begin early and may persist; discontinue mefloquine at the first occurrence of such prodromal symptoms and do not re-challenge. Concomitant or closely timed use (up to ~15 weeks after last dose, reflecting the long half-life) with halofantrine or ketoconazole is specifically warned against due to life‑threatening QTc prolongation; other QT‑affecting drugs warrant caution. A history of major psychiatric disorders (depression, GAD, psychosis, schizophrenia) or seizures is a contraindication to prophylactic use; hypersensitivity to quinine/quinidine is also a contraindication. Due to vestibular and neuropsychiatric risks, use caution with activities requiring alertness and fine motor control (driving, piloting, operating machinery, diving). Start prophylaxis at least 1 week before travel (2 weeks often recommended when feasible) to assess tolerability; continue for 4 weeks after return. Food increases absorption (~40%); take weekly doses with food and water, and avoid alcohol around dosing to reduce CNS side effects. Mefloquine is primarily metabolized by CYP3A4 and is a P‑gp substrate/inhibitor; strong CYP3A4 inhibitors raise exposure and inducers (e.g., rifampin) lower exposure and may compromise efficacy. With chronic/long‑term use, liver enzyme elevations occur in a subset of users; periodic LFT monitoring is advised in prolonged courses and elimination is prolonged in hepatic impairment. Women and individuals with low BMI may be at higher risk for certain neuropsychiatric adverse effects in some cohorts; concurrent alcohol or other chronic medications has been associated with increased adverse event reporting. Breastmilk contains low mefloquine concentrations insufficient to protect an infant; breastfeeding infants require their own antimalarial prophylaxis where indicated.