BMA Concise Guide to Medicine & Drugs

Mefloquine

Brand name Lariam

Used in the following combined preparations None

QUICK REFERENCE

Drug group Antimalarial drug

Overdose danger rating High

Dependence rating Low

Prescription needed Yes

Available as generic No

GENERAL INFORMATION

Mefloquine is used for the prevention and treatment of malaria. It is principally recommended for use in areas where malaria is resistant to other drugs.

However, the use of mefloquine is limited by the fact that it can cause, in some patients, serious side effects that include depression, suicidal tendencies, anxiety, panic, confusion, hallucinations, paranoid delusions, and seizures.

As with all antimalarials, the use of mosquito repellents and a mosquito net at night are as important in preventing malaria as taking the drug itself.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets.

Frequency and timing of doses Prevention Once weekly, starting 2–3 weeks before entering endemic area, and continuing until 4 weeks after leaving. Treatment Up to 3 x daily every 6–8 hours, after food and with plenty of water.

Adult dosage range Prevention 250mg once weekly. Treatment 20–25mg/kg body weight up to a maximum dose of 1.5g.

Onset of effect 2–3 days.

Duration of action Over 1 week. Low levels of the drug may persist for several months.

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children.

Missed dose Take as soon as you remember. If your next dose is due within 48 hours (if taken once weekly for prevention), take a single dose now and skip the next. If vomiting occurs, within 30 minutes of taking a dose, take another.

Stopping the drug If you feel it necessary to stop taking the drug, consult your doctor about alternative treatment before the next dose is due.

OVERDOSE ACTION

Seek immediate medical advice in all cases. Take emergency action if collapse or loss of consciousness occurs.

POSSIBLE ADVERSE EFFECTS

Dizziness, vertigo, nausea, vomiting, headache, and abdominal pain are common adverse effects of mefloquine; discuss with your doctor if these are severe. Rarely, serious adverse effects on the nervous system can occur, including anxiety or panic attacks, depression, hallucinations, and paranoid delusions. if any of these occur, or if you develop hearing problems or palpitations, stop taking the drug and consult your doctor promptly.

INTERACTIONS

General note Mefloquine may increase the effects on the heart of drugs such as beta blockers, calcium channel blockers, and digitalis drugs. It may also affect live-vaccine immunization, which should be completed at least 3 days before the first dose of mefloquine.

Anticonvulsant drugs Mefloquine may decrease the effect of these drugs.

Other antimalarial drugs Mefloquine may increase the risk of adverse effects when taken with these drugs.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have long-term liver or kidney problems.

· You have had epileptic seizures.

· You have had depression or other psychiatric illness.

· You have had a previous allergic reaction to mefloquine or quinine.

· You have heart problems.

· You are taking other medicines.

Pregnancy Not usually prescribed. If unavoidable, the drug is given only after the first trimester. Pregnancy must be avoided during and for 3 months after mefloquine use.

Breast-feeding Not prescribed. The drug passes into the breast milk.

Infants and children Not used in infants under 3 months old. Reduced dose necessary in older children.

Over 60 Careful monitoring is necessary if liver or kidney problems or heart disease are present.

Driving and hazardous work Avoid such activities when taking mefloquine for prevention until you know how the drug affects you. Also avoid during treatment and for 3 weeks afterwards as the drug can cause dizziness or disturb balance.

Alcohol Keep consumption low.

PROLONGED USE

May be taken for prevention of malaria for up to one year.