Halofantrine hydrochloride
Halofantrine hydrochloride (Halfan)
Halofantrine hydrochloride
( hal-oh- FAN-treen)
Pregnancy Category: C Halfan (Rx)

Classification: Antimalarial

Action/Kinetics: Blood schizonticide. Exact mechanism is unknown. At therapeutic doses, it prolongs QTc interval. The primary metabolite, n-butyl halofantrine, and the parent compound are equally active. Has wide interindividual variability in pharmacokinetics; probably due to erratic GI absorption. Peak plasma levels: 5-7 hr. When given with high fat foods, there is a 7-fold increase in peak plasma levels; a 3- to 5-fold increase in absorption seen if given 2 hr after a meal. t 1/2, distribution: 16 hr; t 1/2, terminal elimination: 6-10 days. Excreted through the feces.

Uses: Mild to moderate (100,000 or less parasites/mm ³) malaria due to Plasmodium falciparum or P. vivax.

Contraindications: Use in combination with drugs or clinical situations known to prolong QTc interval, family history of congenital QTc prolongation, in those who previously received mefloquine, or in those with known or suspected ventricular dysrhythmias, AV conduction disorders, or unexplained syncopal attacks. Lactation.

Special Concerns: The safety and efficacy in children, for use in prophylaxis of malaria, in cerebral malaria, or other complicated malaria forms have not been established. Clients with acute P. vivax are at risk of relapse because the drug does not eliminate the exoerythrocytic form; to eliminate the exoerythrocytic phase and avoid relapse, give the client an 8-aminoquinoline after initial halofantrine therapy.

Side Effects: GI: Abdominal pain, diarrhea, N&V;, anorexia, abdominal distention, constipation, dyspepsia, stomatitis. CNS: Dizziness, headache, asthenia, confusion, depression, paresthesia, sleep disorder, convulsions. CV: Chest pain, palpitations, postural hypotension. Musculoskeletal: Rigors, myalgias, arthralgia, back pain. Miscellaneous: Cough, pruritus, fatigue, malaise, rash, urinary frequency, abnormal vision, tinnitus, decreased consciousness.

Laboratory Test Alterations: Hepatic transaminases. Hematocrit and platelet counts. and WBC counts.

Overdose Management: Symptoms: GI distress with abdominal pain, vomiting, cramping, diarrhea, palpitations, dehydration. Treatment: Induce vomiting and institute supportive treatment, including ECG monitoring. Treat dehydration with IV fluids.

Drug Interactions: Use with drugs known to prolong the QTc interval further prolongation of the QTc interval due to the possibility of a fatal reaction.

How Supplied: Tablets: 250 mg, 500 mg

Dosage
?Tablets P. falciparum or P. vivax malaria.
Non-immune clients: 500 mg q 6 hr for 3 doses, followed by a repeat course given 7 days after the first. Semi-immune: Consider omitting the second course of therapy.