Mefloquine

Oral
Prophylaxis of malaria

Oral
Malaria

Severe: Contraindicated.

Should be taken with food. Best taken w/ meals & a full glass of water.

Hypersensitivity to related compounds (e.g. quinine and quinidine); history of blackwater fever; prophylactic use in patients w/ history of psychiatric (including depression) or convulsive disorders; retreatment w/ mefloquine. Severe hepatic impairment. Concomitant use w/ halofantrine.

Patients w/ epilepsy, acute anxiety, restlessness or confusion, cardiac conduction disorders. Renal impairment. Pregnancy and lactation.

Diarrhoea, nausea, vomiting, pruritus, rash, abdominal pain, anorexia, dizziness or vertigo, loss of balance, somnolence and sleep disorders (e.g. insomnia and abnormal dreams). Neuropsychiatric disturbances including motor and sensory neuropathies, ataxia, tremor, visual disorders (e.g. retinal degeneration or optic neuropathy), tinnitus and hearing impairment, convulsions, anxiety, depression, hallucinations, confusion, panic attacks, emotional instability, aggression and agitation, and acute psychosis, suicidal ideation; hair loss, myalgia. Decreased haematocrit and increased transaminase value; thrombocytopenia and leucopenia.

PO: B

May impair ability to drive and operate machineries.

Periodic evaluation of liver function and ophthalmologic examinations (long-term prophylaxis). Neuropsychiatric symptoms; atypical behaviour (suicidal ideation and behaviour) during and after therapy.

Symptoms: Hallucinations, vertigo, nausea, dizziness, tachycardia, hypotension and seizures. Treatment: Symptomatic and supportive treatment. Induced emesis or gastric lavage may be used to empty the stomach. Monitor cardiac function (ECG if possible), neurological and psychiatric status for at least 24 hr.

Increased risk of ECG abnormalities w/ quinine or chloroquine, antihistamines, TCAs and phenothiazines. May increase risk of seizure w/ quinidine or quinine. Concomitant use w/ valproic acid, phenobarbital, carbamazepine and phenytoin may cause loss of seizure control and lower plasma levels of anticonvulsants. Increased risk of QT prolongation and arrhythmia w/ ketoconazole. Concomitant use w/ digoxin, Ca channel blockers, antiarrhythmics and β-blockers may increase the risk of cardiotoxicity. Increased risk of ventricular arrhythmias w/ amiodarone. Concomitant use w/ TCAs, SSRIs, buprion, antipsychotic, tramadol may increase the risk of convulsions. Increased plasma levels w/ metoclopromide. May compromise adequate immunisation by live typhoid vaccine. Vaccinations w/ attenuated live bacteria should be completed at least 3 days prior the 1st dose of mefloquine.
Potentially Fatal: Avoid concomitant use w/ halofantrine as potentially fatal cardiac arrhythmias may occur.

Description: Mefloquine is a 4-methanolquinine antimalarial agent and a blood schizontocide which acts by interfering w/ the parasite's ability to metabolise and utilise erythrocyte Hb. It is active against most Plasmodium spp and is used for prophylaxis and treatment against malaria.
Pharmacokinetics:
Absorption: Well absorbed from the GI tract. Food increases absorption. Time to peak plasma concentration: Approx 17 hr.
Distribution: Widely distributed; crosses placenta and enters breast milk (small amounts). Volume of distribution: Approx 20L/kg. Plasma protein binding: Approx 98%.
Metabolism: Undergoes hepatic metabolism via CYP3A4 isoenzyme to 2,8-bistrifluoromethyl-4-quinoline carboxylic acid (inactive) and other metabolites.
Excretion: Primarily via bile and faeces; urine (9% as unchanged drug, 4% as metabolites). Elimination half-life: Approx 3 wk.

Store at 25°C.

Antimalarials

Anon. Mefloquine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 19/11/2013.

Buckingham R (ed). Mefloquine. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 19/11/2013.

Joint Formulary Committee. Mefloquine. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 19/11/2013.

McEvoy GK, Snow EK, Miller J et al (eds). Mefloquine. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 19/11/2013.

Mefloquine Hydrochloride: Drug Safety Communication - Label Changes Due To Risk of Serious Psychiatric and Nerve Side Effects. U.S. FDA. https://www.fda.gov/. Accessed 19/11/2013.