MEFLOQUINE HYDROCHLORIDE- mefloquine hydrochloride tablet
Roxane Laboratories, Inc.
WARNING
Mefloquine may cause neuropsychiatric adverse reactions that can persist after mefloquine has been discontinued. Mefloquine should not be prescribed for prophylaxis in patients with major psychiatric disorders. During prophylactic use, if psychiatric or neurologic symptoms occur, the drug should be discontinued and an alternative medication should be substituted (see WARNINGS).
DESCRIPTION
Mefloquine hydrochloride USP is an antimalarial agent available as 250 mg tablets of mefloquine hydrochloride USP (equivalent to 228 mg of the free base) for oral administration.
Mefloquine hydrochloride USP is a 4-quinolinemethanol derivative with the specific chemical name of (R*,S*)-(�)-?-2-piperidinyl-2,8-bis(trifluoromethyl)-4-quinolinemethanol hydrochloride. It is a 2-aryl substituted chemical structural analog of quinine. The drug is a white to almost white crystalline compound, slightly soluble in water.
Mefloquine hydrochloride USP has a calculated molecular weight of 414.78
CLINICAL PHARMACOLOGY
Pharmacokinetics
Absorption
The absolute oral bioavailability of mefloquine has not been determined since an intravenous formulation is not available. The bioavailability of the tablet formation compared with an oral solution was over 85%. The presence of food significantly enhances the rate and extent of absorption, leading to about a 40% increase in bioavailability. In healthy volunteers, plasma concentrations peak 6 to 24 hours (median, about 17 hours) after a single dose of mefloquine. In a similar group of volunteers, maximum plasma concentrations in mcg/L are roughly equivalent to the dose in milligrams (for example, a single 1000 mg dose produces a maximum concentration of about 1000 mcg/L). In healthy volunteers, a dose of 250 mg once weekly produces maximum steady-state plasma concentrations of 1000 to 2000 mcg/L, which are reached after 7 to 10 weeks. INDICATIONS AND USAGE
Treatment of Acute Malaria Infections
Mefloquine Hydrochloride Tablets USP are indicated for the treatment of mild to moderate acute malaria caused by mefloquine-susceptible strains of P. falciparum (both chloroquine-susceptible and resistant strains) or by Plasmodium vivax. There are insufficient clinical data to document the effect of mefloquine in malaria caused by P. ovale or P. malariae.
Note: Patients with acute P. vivax malaria, treated with mefloquine, are at high risk of relapse because mefloquine does not eliminate exoerythrocytic (hepatic phase) parasites. To avoid relapse, after initial treatment of the acute infection with mefloquine, patients should subsequently be treated with an 8-aminoquinoline derivative (e.g., primaquine).
Prevention of Malaria
Mefloquine Hydrochloride Tablets USP are indicated for the prophylaxis of P. falciparum and P. vivax malaria infections, including prophylaxis of chloroquine-resistant strains of P. falciparum.
DOSAGE AND ADMINISTRATION
Malaria Treatment in Adults
Treatment of mild to moderate malaria in adults caused by mefloquine-susceptible strains of P. falciparum or by P. vivax: Dosage: Five tablets (1250 mg) mefloquine hydrochloride USP to be given as a single oral dose. The drug should not be taken on an empty stomach and should be administered with at least 8 oz (240 mL) of water.
If a full-treatment course with mefloquine does not lead to improvement within 48 to 72 hours, mefloquine should not be used for retreatment. An alternative therapy should be used. Similarly, if previous prophylaxis with mefloquine has failed, mefloquine should not be used for curative treatment (see INDICATIONS AND USAGE).
Note: Patients with acute P. vivax malaria, treated with mefloquine, are at high risk of relapse because mefloquine does not eliminate exoerythrocytic (hepatic phase) parasites. To avoid relapse after initial treatment of the acute infection with mefloquine, patients should subsequently be treated with an 8-aminoquinoline derivative (e.g., primaquine).
Malaria Prophylaxis in Adults
Dosage: One 250 mg mefloquine hydrochloride tablet once weekly.
Prophylactic drug administration should begin 1 week before arrival in an endemic area. Subsequent weekly doses should be taken regularly, always on the same day of each week, preferably after the main meal. To reduce the risk of malaria after leaving an endemic area, prophylaxis must be continued for 4 additional weeks to ensure suppressive blood levels of the drug when merozoites emerge from the liver. Tablets should not be taken on an empty stomach and should be administered with at least 8 oz (240 mL) of water.
In certain cases, e.g., when a traveler is taking other medication, it may be desirable to start prophylaxis 2 to 3 weeks prior to departure, in order to ensure that the combination of drugs is well tolerated (see PRECAUTIONS: Drug Interactions).