INDICATIONS     CONTRA-INDICATIONS     DOSAGE     SIDE-EFFECTS     PREGNANCY     OVERDOSE     IDENTIFICATION     PATIENT INFORMATION

Logo 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 patient acceptance, it has essentially replaced aminosalicylic acid.

CONTRA-INDICATIONS:
Ethambutol should be given in reduced dosage to patients with impaired kidney function. It should be given with care in patients with reduced visual acuity and its use is probably best avoided during pregnancy. Serum concentrations should not exceed 5 µg per mL.

DOSAGE AND DIRECTIONS FOR USE:
In the treatment of tuberculosis, serum concentrations of 3 to 5 µg of ethambutol per mL are considered necessary and they are generally attained with a dose of 15 to 25 mg per kg body weight daily. A single dose of 25 mg per kg may be given for 2 months and thereafter reduced to 15 mg per kg. It has been suggested that tests of visual acuity should be regularly performed on patients being treated with ethambutol.

SIDE-EFFECTS AND SPECIAL PRECAUTIONS:
The most important side-effect of ethambutol hydrochloride is optic neuritis, resulting in decrease of visual acuity and loss of ability to perceive the colour green. This is quite uncommon with a dose of 25 mg/kg per day, but occurs more often with 50 mg/kg per day. The intensity of the visual difficulty is related to the duration of the therapy after decrease in visual acuity first becomes apparent and it may be unilateral or bilateral. Recovery usually occurs when ethambutol is withdrawn; the time required is a function of the degree of visual impairment.
Ethambutol produces very few reactions. Daily doses of less than 25 mg/kg are minimally toxic. Among the side-effects that have been observed are dermatitis, pruritis, joint pain, gastro-intestinal upset, abdominal pain, fever, malaise, headache, dizziness, mental confusion, disorientation and possible hallucination. Numbness and tingling of the fingers due to peripheral neuritis are infrequent. Anaphylaxis and leukopenia are rare.
Ethambutol therapy results in an increased concentration of urate in the blood in about 50% of patients, due to decreased renal excretion of uric acid. The effects may be detectable as early as 24 hours after a single dose or as late as 90 days after treatment is started. This untoward effect is possibly enhanced by isoniazid and pyridoxine.

KNOWN SYMPTOMS OF OVERDOSAGE AND PARTICULARS OF ITS TREATMENT:
The symptoms of overdosage are those stated under side-effects above and in these cases the dosage should be reduced or the medicine discontinued.

CONDITIONS OF REGISTRATION OF THE DRUG (IF ANY) IMPOSED BY THE COUNCIL:
To be advertised to the professions only.

IDENTIFICATION:
100 mg Tablets:
Yellow biconvex film-coated tablets, 8 mm in diameter.
400 mg Tablets: Grey biconvex film-coated tablets, 12,5 mm in diameter.

PRESENTATION:
Packs of 100 and 1000 tablets.

STORAGE DIRECTIONS:
Store below 25 C, protected from light.
KEEP OUT OF REACH OF CHILDREN.

REGISTRATION NUMBER:
100 mg:
J/20.2 3/261
400 mg: J/20.2.3/262

NAME AND BUSINESS ADDRESS OF APPLICANT:
Pharmacare Limited, 7 Fairclough Road, PORT ELIZABETH 6020

DATE OF PUBLICATION OF THIS PACKAGE INSERT:
11/03/1977

        G442A

KOHLER C&P P.E.

SAEPI HOME PAGE      TRADE NAME INDEX      GENERIC NAME INDEX      FEEDBACK
Information presented by Malahyde Information Systems © Copyright 1996,1997,1998