Mefloquine hydrochloride
Mefloquine hydrochloride (Lariam)
Mefloquine hydrochloride
(meh- FLOH-kwin)
Pregnancy Category: C Lariam (Rx)

Classification: Antimalarial

Action/Kinetics: Related chemically to quinine and acts as a blood schizonticide. It may increase intravesicular pH in acid vesicles of parasite. Mefloquine is a mixture of enantiomeric molecules that results in differences in the rates of release, absorption, distribution, metabolism, elimination, and activity of the drug. It shows myocardial depressant activity with about 20% of the antifibrillatory activity of quinidine and 50% of the increase in the PR interval noted with quinine. t 1/2: 13-24 days (average 3 weeks). Is 98% bound to plasma proteins and is concentrated in blood erythrocytes (i.e., the target cells in treatment of malaria).

Uses: Mild to moderate acute malaria caused by mefloquine-susceptible strains of Plasmodium falciparum (both chloroquine susceptible and resistant strains) or P. vivax. Data are not available regarding effectiveness in treating P. ovale or P. malariae. Also, prophylaxis of P. falciparum and P. vivax infections, including prophylaxis of chloroquine-resistant strains of P. falciparum. NOTE: Clients with acute P. vivax malaria are at a high risk for relapse as mefloquine does not eliminate the exoerythrocytic (hepatic) parasites. Thus, these clients should also be treated with primaquine. NOTE: Strains of P. falciparum are reported to be resistant to mefloquine.

Contraindications: Hypersensitivity to mefloquine or related compounds.

Special Concerns: Use with caution during lactation and in those with psychiatric disturbances due to the possibility of emotional reactions. Safety and effectiveness have not been determined in children.

Side Effects: NOTE: At the doses used, it is difficult to distinguish side effects due to the drug from symptoms attributable to the disease itself. When used for treatment of acute malaria. G I: N&V;, diarrhea, abdominal pain, loss of appetite. CNS: Dizziness, fever, headache, fatigue, emotional problems, seizures. Miscellaneous: Myalgia, chills, skin rash, tinnitus, bradycardia, hair loss, pruritus, asthenia. When used for prophylaxis of malaria. C NS: Dizziness, syncope, encephalopathy of unknown etiology. Miscellaneous: Vomiting, extrasystoles. Postmarketing surveillance. C NS: Vertigo, psychoses, confusion, anxiety, depression, seizures hallucinations, insomnia, abnormal dreams, forgetfulness, motor and sensory neuropathy. CV: Hypertension, hypotension, tachycardia, palpitations. Dermatologic: Flushing, urticaria, Stevens-Johnson syndrome, erythema multiforme. Miscellaneous: Visual disturbances.

Laboratory Test Alterations: When used for prophylaxis: Transient transaminases, leukocytosis, thrombocytopenia. When used for treatment of acute malaria: Hematocrit, transient transaminases, leukocytosis, thrombocytopenia.

Overdose Management: Symptoms: Cardiotoxic effects, vomiting, diarrhea. Treatment: Induce vomiting and administer fluid therapy to treat vomiting and diarrhea.

Drug Interactions: Beta-adrenergic blocking agents / ECG abnormalities or cardiac arrest Chloroquine / Risk of seizures Quinidine / Risk of ECG abnormalities or cardiac arrest Quinine / Risk of seizures, ECG abnormalities, or cardiac arrest Valproic acid / Loss of seizure control and valproic acid blood levels

How Supplied: Tablet: 250 mg

Dosage
?Tablets Mild to moderate malaria caused by susceptible strains of P. falciparum or P. vivax.
1,250 mg (5 tablets) as a single dose with at least 8 oz of water (not to be taken on an empty stomach).
Prophylaxis of malaria.
250 mg (1 tablet) once a week for 4 weeks; then, 1 tablet every other week. The CDC recommends a single dose taken weekly starting 1 week before travel, continued weekly during travel, and for 4 weeks after leaving malarious areas. Pediatric, 15-19 kg: 1/4 tablet (62.5 mg) weekly; 20-30 kg: 1/2 tablet (125 mg) weekly; 31-45 kg: 3/4 tablet (187.5 mg) weekly; over 45 kg: 1 tablet (250 mg) weekly. The CDC recommends a similar dosing schedule for children as for adults.