Country: South Africa
Language: English
Source: South African Health Products Regulatory Authority (SAHPRA)
Lennon
PURDERAL® P 100 mg TABLETS PURDERAL® P 400 mg TABLETS SCHEDULING STATUS: S3 PROPRIETARY NAME (and dosage form): PURDERAL ® P 100 mg TABLETS PURDERAL ® P 400 mg TABLETS COMPOSITION: Each tablet contains 100 mg (400 mg) of Ethambutol Hydrochloride. PHARMACOLOGICAL CLASSIFICATION: A 20.2.3 Tuberculostatics PHARMACOLOGICAL ACTION: About 75% to 80% of an orally administered dose of ethambutol is absorbed from the gastro-intestinal tract. Plasma concentrations are maximal in man 2 to 4 hours after the medicine is taken and are proportional to the dose. A single dose of 25 mg/kg produces a plasma concentration of about 5 µg/mL at 2 hours. The medicine has a relatively long half-life; about 50% of the peak concentration is present in the blood at 8 hours and less than 10% at 24 hours. The medicine enters erythrocytes with ease; 1 hour after an intravenous dose two to three times as much ethambutol is present in the erythrocytes as in the plasma. Red blood cells thereby serve as a depot from which the medicine slowly enters the plasma. Within 24 hours 50% of an ingested dose of ethambutol is excreted unchanged in the urine; up to 15% is excreted in the form of two metabolites, an aldehyde and a dicarboxylic acid is excreted by tubular secretion or solely by glomerular filtration, the latter is thought to play the primary role. INDICATIONS: Ethambutol hydrochloride is a tuberculostatic agent. It is reported to be inhibitory to mycobacterium tuberculosis in concentrations of 0,5 to 2 µg per mL. Cross-resistance with other anti-tuberculous medicines has not been reported. It should only be used in conjunction with other tuberculostatic agents such as isoniazid. Because of greater tuberculostatic activity, lower incidence of toxic side-effects, and better patien Read the complete document