Mefloquine Hydrochloride

Trade Names:Mefloquine HCl- Tablets 250 mg

Trade Names:Lariam- Tablets 250 mg

Pharmacology

Antimalarial agent that acts as a blood schizonticide. Mechanism of action is unknown.

Pharmacokinetics

Distribution

Mefloquine Vd is approximately 20 L/kg and the protein binding is 98%.

Metabolism

At least 1 metabolite has been identified.

Elimination

Metabolism of mefloquine is primarily hepatic. The total Cl is 30 mL/min and the t _½ is 13 to 24 days (mean, approximately 3 wk).

Indications and Usage

Treatment of mild to moderate malaria caused by mefloquine-susceptible strains of Plasmodium falciparum or P. vivax . Prevention of malaria caused by P. falciparum or P. vivax . Patients with acute P. vivax need subsequent treatment with 8-aminoquinolone to prevent relapse.

Contraindications

Acute depression; history of psychosis or convulsions; hypersensitivity to the drug or related compounds (eg, quinine, quinidine).

Dosage and Administration

PO 5 tablets (1,250 mg) as a single dose with food and at least 240 mL of water.

PO 20 to 25 mg/kg as a single dose or split into 2 doses 6 to 8 h apart with food and at least 240 mL of water.

PO 250 mg once weekly starting 1 wk before exposure and continuing 4 wk after with food and at least 240 mL of water.

PO 3 to 5 mg/kg once weekly starting with 1 wk before exposure and continuing 4 wk after. Take with food and at least 240 mL of water.

PO ¼ tablet.

PO ½ tablet.

PO ¾ tablet.

PO 1 tablet.

Storage/Stability

Store tablets at controlled room temperature (59° to 86°F).

Drug Interactions

Reduced seizure control.

Potential for QTc interval prolongation.

Concurrent use can cause potentially fatal QTc interval prolongation.

Increased risk of seizures and ECG abnormalities.

Reduced effectiveness.

Laboratory Test Interactions

Hematocrit, decrease; leukocytosis (during prophylactic treatment); leukopenia; thrombocytopenia; transaminase, transient increase.

Adverse Reactions

CNS

Dizziness; headache; somnolence.

GI

Nausea; vomiting; diarrhea; abdominal pain; loss of appetite.

Miscellaneous

Myalgia; fever; chills; rash; fatigue; tinnitus.

Precautions

Pregnancy

Category C .

Lactation

Eliminated in breast milk.

Children

Safety and efficacy in children younger than 6 mo of age not established.

Hepatic Function

Impaired elimination of mefloquine.

Special Risk Patients

Use caution in patients with acute depression or history of psychosis or convulsions.

CV

Risk of ECG alterations, sinus bradycardia, sinus arrhythmia, first degree AV block, prolonged QTc interval, and abnormal T waves.

Epileptic patients

Increased risk of seizures.

Patient Information

• Advise patient to take each prophylactic dose at the same time each day with food and at least 8 oz of water.
• Instruct patient taking mefloquine for prophylaxis that first dose should be taken 1 wk prior to arrival in malaria-infected area and that subsequent doses should be taken on the same day of the week while in the malaria-infected area and for 4 wk after leaving the malaria-infected area.
• Advise patient that protective clothing, insect repellants, and bednets are important components of malaria prophylaxis.
• Instruct patient taking prophylactic doses to discontinue drug and notify health care provider immediately if any of the following develop: acute anxiety, depression, restlessness, confusion, paranoia, hallucinations, or change in behavior. Alternative therapy will be necessary if mefloquine is discontinued.
• Advise patient to notify health care provider if severe or persistent vomiting or diarrhea develop, vomiting within 1 h of taking dose occurs often, other bothersome adverse reactions, or if therapy is prematurely discontinued for any reason.
• Advise patient that drug may cause dizziness or other nervous system disorders and to use caution while driving or performing other tasks requiring mental alertness until tolerance is determined.
• Advise women of childbearing potential to use effective contraception while taking mefloquine for malaria prophylaxis.
• Advise patient that if a febrile illness develops during or after return from a malaria-endemic area, seek health care and inform the doctor of possible malaria exposure.

Copyright © 2009 Wolters Kluwer Health.