- Pregnant or lactating; history of presence of significant cardiovascular, pulmonary, hepatic, hematologic, gastrointestinal, endocrine, immunologic, musculoskeletal, dermatologic, neurologic, or psychiatric disease; positive at screening for HIV, HbsAg, or HCV; QTc >440 msec (male) or 450 msec (female) or PR >200 msec, sitting BP < 90/55, sitting radial pulse < 45 bpm at screening or baseline; history of G6PD deficiency, myasthenia gravis, or optic neuritis; hypersensitivity or idiosyncratic reaction to mefloquine or quinidine; recent/ongoing use of drugs or substances known to inhibit or induce CYP P450 enzymes and/or P-glycoprotein or quinine; hx of alcoholism or drug abuse within previous 2 years; donation of blood or plasma within 56 days prior to dosing; receipt of study medication in another clinical trial within 30 days of dosing