PHARMACOLOGICAL ACTION: Tetracycline hydrochloride is a broad spectrum antibiotic produced by fermentation from a species of Streptomyces.
Sodium hexametaphosphate enhances the absorption of tetracycline from the gastro-intestinal tract. Tetracycline is excreted primarily by the kidneys.
Laboratory and clinical studies have shown that tetracycline is effective against Diplococcus pneumoniae, Neisseria gonorrhoea, Neisseria meningitidis, certain clostridia, Haemophilus influenza, Shigella, Klebsiella pneumoniae, and Enterobacter aerogenes.
Tetracycline is also effective against certain Rickettsia, large viruses of the lymphogranuloma-psittacosis-trachoma group and Mycoplasma pneumoniae (Eaton agent).
INDICATIONS: TETREX is indicated in the treatment of the following infections when due to sensitive organisms:
Infections of the respiratory tract, such as pneumonia, chronic bronchitis, sinusitis, laryngitis, pharyngitis and otitis media.
Infections of the gastrointestinal tract, such as bacterial gastro-enteritis (Gram negative coliform bacteria, Shigella, Bacteroides).
Infections of the genitourinary tract, such as gonorrhoea, lymphogranuloma inguinale and cystitis, urethritis and renal infections caused by tetracycline sensitive organisms.
Systemic infections, such as mixed infections, peritonitis, typhus infections (epidemic, endemic and scrub typhus) and other rickettsial infections (Mediterranean-boutonneuse fever, South African tick-bite fever, rickettsial pox, Q-fever).
Note: Resistance may develop to all tetracyclines (i.e. strains of pneumococci, E. coli and Shigellae). Indicated laboratory studies, including sensitivity tests should be performed in the case of resistant infections.
CONTRA-INDICATIONS: Renal Impairment:
This medicine is contra-indicated in individuals who have shown serious hypersensitivity to tetracycline.
WARNINGS: Tetracycline may form a stable calcium complex in any bone- forming tissue with no serious harmful effects reported thus far in humans. However, use of tetracycline during tooth development (last half of pregnancy, infancy and childhood to the age of 8 years) may cause permanent discoloration of the teeth (yellow-grey-brownish). This effect occurs mostly during long-term therapy, but it has been observed following short treatment courses. Enamel hypoplasia has been observed in a few children. Tetracycline therefore, should not be used in this age group unless other drugs are not likely to be effective or are contra-indicated.
Use with care in patients with liver function impairment.
Because the tetracyclines have been shown to depress plasma prothrombin activity, patients who are on anticoagulant therapy may require downward adjustment of their anticoagulant dosage.
Do not use concomitantly with hepatotoxic medicines.
In long-term therapy, periodic laboratory evaluation of organ systems, including haematopoietic, renal and hepatic studies should be performed. Usage in pregnancy: (See above warning about the use during tooth development).
Symptoms of myasthenia may be aggravated.
Results in animal studies indicate that tetracyclines cross the placenta, are found in foetal tissues and can have toxic effects on the developing foetus (often related to retardation of skeletal development). Evidence of embryo-toxicity has also been noted in animals treated early in pregnancy.
Pseudotumour cerebri may occur.
DOSAGE AND DIRECTIONS FOR USE:
Adults: The usual dose is 1 g per day in 4 divided doses of 250 mg each.
Severe infections require higher doses.
Treatment of uncomplicated gonorrhoea when penicillin is contra-indicated.
Males and females: 1,5 g initially, followed by 0,5 g 6 hourly for a total of 9 g.
In the treatment of gonorrhoea patients with a suspected lesion of syphilis should have dark-field examinations before receiving TETREX. In all other cases where concomitant syphilis is suspected, monthly serological tests should be made for a minimum of four months.
Pustular acne: The recommended dose is 250 mg, 4 times daily or 500 mg twice daily. Reduce dosage as soon as the pustular element is controlled.
Chronic bronchitis: The recommended dose is 250 mg four times daily or 500 mg twice daily. Higher doses may be required to control acute episodes. The maximum dose for adults should not exceed 3g per day.
Children: (See Warnings).
Children weighing more than 40 kg should be given the recommended adult dose.
The maximum dose for children should not exceed 50 mg/kg bodymass/day. Therapy for most infections should be continued for 24 - 48 hours after the patient has become asymptomatic or afebrile.
Oral dosage forms of tetracycline should be given at least one hour before or two hours following meals. Tetracycline should not be given with milk or calcium-containing food. Iron salts and antacids containing aluminium, calcium or magnesium impair absorption and should not be given to patients taking oral tetracycline.
SIDE-EFFECTS AND SPECIAL PRECAUTIONS: Anorexia, nausea, vomiting, diarrhoea, stomatitis, glossitis, dysphagia, enterocolitis, and pruritus ani may occur.
Maculopapular and erythematous rashes. Exfoliative dermatitis has been reported but is uncommon. Onycholysis and discoloration of the nails have been noted rarely.
Hypersensitivity reactions to tetracycline including urticaria angioneurotic oedema, anaphylaxis, anaphylactoid purpura, pericarditis and exacerbations of systemic lupus erythematosus have been reported.
Hypersensitive individuals have been reported to develop photodynamic reactions (usually allergic) during the use of tetracycline derivatives (particularly demethylchlortetracycline, occasionally chlortetracycline or oxytetracycline and rarely tetracycline).
Individuals with a history of photosensitivity should be instructed to avoid direct exposure to natural or artificial sunlight while under treatment with any tetracycline drug. Treatment should be discontinued at first evidence of skin discomfort.
Azotemia, which is apparently dose related, may occur. Cholestasis has been reported rarely and is usually associated with high dosage levels.
Haemolytic anaemia, thrombocytopenia, neutropenia and eosinophilia have been reported in patients treated with tetracycline.
Vitamin deficiencies may occur.
The possibility of the occurrence of superinfections with mycotic organisms or other pathogens should be kept in mind when using tetracycline. Raised intracranial pressure in adults may occur.
KNOWN SYMPTOMS OF OVERDOSAGE AND PARTICULARS OF ITS TREATMENT: See side-effects and special precautions. Treatment is symptomatic and supportive.
IDENTIFICATION: Orange opaque cap and yellow opaque body, imprinted Bristol on cap and body.
PRESENTATION: TETREX capsules are available in plastic containers, containing 100 capsules.
STORAGE INSTRUCTIONS: Store in a cool dry place.
Temperature should not exceed 25°C
Keep out of reach of children.
REGISTRATION NUMBER: E/20.1.1/235
NAME AND BUSINESS ADDRESS OF THE APPLICANT: Bristol-Myers Squibb (Pty) Ltd *
AMR Park, 1 Concorde Road East,
DATE OF PUBLICATION OF THE PACKAGE INSERT: July 1989