CHLOROQUINE- chloroquine phosphate tablet
CHLOROQUINE- chloroquine phosphate tablet, coated
West-ward Pharmaceutical Corp
Rev. 05/10
Rx Only
For Malaria and Extraintestinal Amebiasis
DESCRIPTION
Chloroquine Phosphate, USP, is a 4-aminoquinoline compound for oral administration. It is a white, odorless, bitter tasting, crystalline substance, freely soluble in water.
Chloroquine Phosphate Tablets are an antimalarial and amebicidal drug.
Each tablet, for oral administration, contains 250 mg chloroquine phosphate (equivalent to 150 mg base) or 500 mg chloroquine phosphate (equivalent to 300 mg base).
Inactive ingredients 250 mg: Calcium Stearate, Colloidal Silicon Dioxide, Dibasic Calcium Phosphate, Microcrystalline Cellulose, and Talc.
Inactive ingredients 500 mg: Colloidal Silicon Dioxide, Corn Starch, Lactose Monohydrate, Magnesium Stearate, Microcrystalline Cellulose, Polyvinylpyrrolidone, Sodium Starch Glycolate, and Titanium Dioxide. Film Coating and Polishing Solution contains: D&C Red #27 Aluminum Lake, D&C Yellow #10 Aluminum Lake, FD&C Blue #1 Aluminum Lake, Hypromellose, Polyethylene Glycol, Polysorbate 80 and Titanium Dioxide.
Chemically, it is 7-chloro-4-[[4-(diethylamino)-1-methylbutyl]amino] quinoline phosphate (1:2) and has the following structural formula:
Structural Formula
(click image for full-size original)
CLINICAL PHARMACOLOGY
Chloroquine is rapidly and almost completely absorbed from the gastrointestinal tract, and only a small proportion of the administered dose is found in the stools. Approximately 55% of the drug in the plasma is bound to nondiffusible plasma constituents. Excretion of chloroquine is quite slow, but is increased by acidification of the urine. Chloroquine is deposited in the tissues in considerable amounts. In animals, from 200 to 700 times the plasma concentration may be found in the liver, spleen, kidney, and lung; leukocytes also concentrate the drug. The brain and spinal cord, in contrast, contain only 10 to 30 times the amount present in plasma.
Chloroquine undergoes appreciable degradation in the body. The main metabolite is desethylchloroquine, which accounts for one fourth of the total material appearing in the urine; bisdesethylchloroquine, a carboxylic acid derivative, and other metabolic products as yet uncharacterized are found in small amounts. Slightly more than half of the urinary drug products can be accounted for as unchanged chloroquine.
Microbiology
Mechanism of Action
Chloroquine is an antimalarial agent. While the drug can inhibit certain enzymes, its effect is believed to result, at least in part from its interaction with DNA. However, the mechanism of plasmodicidal action of chloroquine is not completely certain.