Products
Mefloquine is commercially available in the form of film-coated tablets (generic: mephaquine). The active ingredient was approved in many countries in 1984. Distribution of the original Lariam (Roche) was discontinued in 2014 for commercial reasons.
Structure and properties
Mefloquine (C17H16F6N2O, Mr = 378.3 g/mol) is a fluorinated quinoline and piperidine derivative and an analog of quinine. It is present in drugs as mefloquine hydrochloride, a racemate and white to pale yellow crystalline powder that is very sparingly soluble in water. Mefloquine has a bitter and slightly burning taste.
Effects
Mefloquine (ATC P01BC02) has antiparasitic (schizontocidal) properties against the malaria parasites , , and . It has a long half-life of two to four weeks.
Indications
For the prevention, treatment, and emergency treatment of malaria. Off-label use:
- In 2020, mefloquine was investigated for the treatment of covid-19, infection with the new coronavirus.
Dosage
According to the professional information. For prevention, tablets are taken once a week on the same day after a meal. Chemoprophylaxis is started at least one week before travel and continued for up to four weeks after travel.
Contraindications
- Hypersensitivity to mefloquine or related substances.
- Prophylaxis in patients with a history of psychiatric illness or convulsions
- Combination with halofantrine, St. John’s wort, and rifampicin.
Full details of precautions and interactions can be found in the drug label.
Interactions
Mefloquine is a substrate of CYP3A4 and a substrate and inhibitor of P-glycoprotein. Corresponding drug-drug interactions are possible, for example with ketoconazole and rifampicin. Related antimalarials such as halofantrine or quinine may cause QT interval prolongation and convulsions. Other interactions have been described with drugs that affect cardiac conduction, anticonvulsants, and typhoid vaccines, among others.
Adverse effects
The most common potential adverse effects include drowsiness, impaired balance, headache, drowsiness, sleep disturbances, abnormal dreams, dizziness, nausea, vomiting, abdominal pain, and diarrhea. Mefloquine can potentially cause numerous side effects, including, for example, cardiovascular disturbances, visual disturbances, blood count disturbances, and severe skin rashes. It can cause psychiatric symptoms such as anxiety, paranoia, depression, hallucinations, and psychosis. Suicidal ideation and suicides have also been reported.
