Mef-Q

Indications

Mefloquine is an antimalarial medicine. It is used to prevent malaria in travellers visiting areas where malaria, including chloroquine-resistant Plasmodium falciparum, is common, and to treat mild to moderate malaria, usually in combination with an artemisinin such as Artesunate.

How It Works

Mefloquine kills the blood stages of the malaria parasite that cause symptoms. It is thought to interfere with how the parasite handles haemoglobin and to block its protein-making machinery, so the parasites inside red blood cells die. It does not kill the dormant liver stages of vivax malaria.

Dosage and Administration

Prevention in adults: 250 mg once a week, on the same day each week, starting 1 to 3 weeks before travel, continuing during the stay and for 4 weeks after leaving the malaria area, or as prescribed. Treatment doses are based on body weight and are given as prescribed, often with Artesunate. Take tablets after a meal with a full glass of water. Children's doses are based on weight.

Interactions

• Quinine, Quinidine and Chloroquine: higher risk of seizures and heart rhythm problems; leave a gap after quinine treatment as advised.
• Halofantrine and Ketoconazole: dangerous QT prolongation; Halofantrine must not be given with or after Mefloquine.
• Other medicines that prolong the QT interval, such as some antiarrhythmics, antipsychotics and antibiotics.
• Antiepileptics (Valproate, Carbamazepine, Phenytoin): seizure control may worsen.
• Rifampicin: lowers Mefloquine levels.
• Live oral typhoid vaccine: complete vaccination at least 3 days before the first Mefloquine dose.

Contraindications

• Allergy to Mefloquine, Quinine or Quinidine.
• Current or past depression, anxiety disorder, psychosis, schizophrenia or other serious mental illness, or suicidal thoughts (for prevention).
• Epilepsy or a history of seizures.
• Severe liver disease, and a history of blackwater fever.
• Recent treatment with Halofantrine.

Side Effects

Common effects include nausea, vomiting, diarrhoea, stomach pain, dizziness, headache, sleep problems and vivid or abnormal dreams. It can cause neuropsychiatric effects such as anxiety, depression, restlessness, confusion and hallucinations, and nervous system effects such as dizziness, loss of balance and ringing in the ears, which in rare cases can last for months or longer after stopping.

Get urgent medical help, and stop the medicine if used for prevention, if you develop anxiety, depression, restlessness, confusion, unusual behaviour, thoughts of suicide, hallucinations, dizziness or loss of balance, ringing in the ears, a seizure, a fast or irregular heartbeat, fainting, or signs of a severe allergic reaction or rash.

Pregnancy and Lactation

Malaria is very dangerous in pregnancy. Mefloquine may be used in all trimesters when travel to a high-risk area cannot be avoided and the doctor considers it suitable. Women should avoid becoming pregnant for 3 months after the last dose if possible. Small amounts pass into breast milk; it is generally considered acceptable during breastfeeding, but ask your doctor. The infant also needs its own protection.

Precautions and Warnings

Read the patient alert card if one is given. Start prevention early enough to check how you tolerate it. Avoid driving, climbing, diving or operating machinery if you feel dizzy or unsteady. Tell your doctor about heart, liver, eye or mental health problems. Long-term users may need eye and liver checks. Also use mosquito nets and repellents, because no medicine gives full protection.

Overdose

Overdose may cause severe nausea, vomiting, dizziness, confusion, seizures and dangerous heart rhythm problems. Seek emergency medical help at once.

Therapeutic Class

Antimalarial (quinoline methanol).

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.