MEH-flow-kwin

Therapeutic Classification: antimalarials

Pharmacologic Classification: quinine analogues

• Treatment of mild to moderate acute malaria caused by susceptible strains of Plasmodium falciparum or P. vivax, including chloroquine-resistant strains.
• Prevention of malaria caused by Plasmodium falciparum or P. vivax.

• Eradicates the blood schizonticidal stage of malaria.

• Resolution/prevention of malaria.

Absorption: Well absorbed following oral administration.

Distribution: Extensive tissue distribution including parasitized erythrocytes.

Protein Binding: 98%.

Metabolism/Excretion: Extensively metabolized by the liver primarily by the CYP3A4 isoenzyme; metabolites do not have antimalarial activity. Excreted mostly in bile and feces as metabolites. Small amounts excreted in urine.

Half-life: 2–4 wk.

(plasma concentrations)

Contraindicated in:

• Hypersensitivity (cross sensitivity with quinine and quinidine may occur)
• Depression, generalized anxiety disorder, psychosis, schizophrenia, major psychiatric disorder, or seizures (prophylaxis only)
• Life-threatening malaria (initial treatment should be with an intravenous drug)
• Lactation: Lactation.

Use Cautiously in:

• Malaria caused by P. vivax (relapse rates are high, subsequent treatment with and 8-aminoquinoline is required)
• History of suicide attempt or ideation
• History of cardiovascular disease (may ↑ risk of adverse cardiovascular reactions)
• Psychiatric disorders
• Hepatic impairment (may ↑ risk of adverse reactions)
• OB: Use during pregnancy only if potential maternal benefit justifies potential fetal risk
• Pedi: Children <6 mo (safety and effectiveness not established)
• Geri: Older adults may have ↑ risk of adverse cardiovascular reactions.

CV: arrhythmias (including sinus bradycardia, sinus arrhythmia, first degree AV block, abnormal T waves), ECG changes, syncope.

Derm: rash.

EENT: tinnitus.

GI: abdominal pain, diarrhea, vomiting (↑ in children), nausea.

Neuro: dizziness, vertigo, fatigue, neuropsychiatric symptoms.

Drug-Drug:

• Concurrent use of ketoconazole or other CYP3A4 inhibitors may ↑ levels and the risk QTc prolongation and serious cardiovascular adverse reactions.
• Concurrent use with quinidine or quinine may ↑ risk of seizures.
• Risk of QTc prolongation may be ↑ by concurrent use of antiarrhythmics, beta-blockers, some antihistamines, tricyclic antidepressants or phenothiazines.
• May ↓ antibody response to live-virus vaccines (vaccinations should be completed 3 days prior to mefloquine.
• Concurrent use of CYP3A4 inducers, including rifampin, may ↓ levels and effectiveness.
• May ↓ levels and effectiveness of anticonvulsants including carbamazepine, phenobarbital, phenytoin or valproates.
• Effects of drugs that are P-glycoprotein substrates or P-glycoprotein inhibitors may affect or be affected by mefloquine.

• PO (Adults): Mild to moderate malaria: 1250 mg (5 tablets as a single dose), patients with acute P. vivax should also be subsequently treated with an 8-aminoquinoline; prophylaxis: 250 mg once weekly beginning one wk before arrival in endemic area (sooner if concurrent medications decrease tolerance) and continued for 4 wk after returning.
• PO (Children 20 kg): Mild to moderate malaria: 20–25 mg/kg (may be split into two doses 6–8 hr apart, if vomiting occurs, all or part of the dose may be repeated); patients with acute P. vivax should also be subsequently treated with an 8-aminoquinoline; prophylaxis: 5 mg/kg once weekly (for patients >45 kg: use one 250 mg tablet, if 30–45 kg: use ¾ tablet, if 20–30 kg: use ½ tablet) beginning one wk before arrival in endemic area (sooner if concurrent medications decrease tolerance) and continued for 4 wk after returning.

• Tablets: 250 mg;

• Assess patient for improvement in signs and symptoms of malaria daily throughout course of therapy.

• Monitor hepatic function periodically during prolonged prophylactic therapy.
  • May cause ↓ hematocrit and transient ↑ AST and ALT, leukopenia, and thrombocytopenia.

• There are no antidotes. Monitor cardiac function (ECG) and neuropsychiatric status for at least 24 hr. Treat symptomatically.

• Do not confuse mefloquine with Malarone.
• PO: Administer with food, preferably after eating main meal, and at least 8 ounces of water. May be crushed and mixed with small amount of water, milk, or other beverage for children or others unable to swallow whole.

• Instruct patient to take medication exactly as directed and continue full course of therapy even if feeling better. Advise patient to read Medication Guide before starting therapy and with each Rx refill in case of changes.
• Malaria Prophylaxis: Review methods of minimizing exposure to mosquitoes with patients receiving mefloquine prophylactically (use repellent, wear long-sleeved shirt and long trousers, use screen or netting).
  • Advise patient to notify health care professional if fever develops while traveling or within 2 mo of leaving an endemic area.
  • Advise patient taking mefloquine for a year of longer to have eye exams, especially if vision changes occur.
• May cause dizziness and loss of balance. Caution patient to avoid driving and other activities requiring alertness and fine motor coordination until response to medication is known.
• Advise patient to tell health care professional what medications they are taking and to avoid taking new Rx, OTC, vitamins, or herbal products without consulting health care professional.
• Advise females of reproductive potential to use effective contraception during malaria prophylaxis with mefloquine and for 3 mo after last dose and to avoid breastfeeding during therapy.
• Advise patient to carry a wallet card containing information about mefloquine and potential side effects at all times during therapy.

• If no improvement within 48 to 72 hr, do not use mefloquine for retreatment. If mefloquine for prophylaxis failed, use another agent for curative treatment.

Lariam