Medicine for acne: Oral antibiotics: Tetracycline

Tetracycline.
Tetracycline is the most widely prescribed oral antibiotic for acne. One major disadvantage is the requirement that tetracycline not be taken with food (particularly dairy products), certain antacids, and iron, all of which interfere with the intestinal absorption of the drug. Failure to adhere to these restrictions accounts for many of the reported therapeutic failures of tetracycline.
DOSING.
Efficacy and compliance are obtained by starting tetracycline administration at 500 mg twice each day and continuing this dosage until a significant decrease in the number of inflamed lesions occurs, usually in 3 to 6 weeks. Thereafter the dosage may be decreased to 250 mg twice each day or oral therapy may be discontinued in favor of topical antibiotics. Patients with severe pustular and cystic acne or those who do not respond to 1 gm/day might respond to a higher dosage of tetracycline (1.5 to 3.0 gm/day). These higher dosages may not be tolerated by some patients. Patients who do not respond after 6 weeks of adequate dosages of oral tetracycline should be introduced to an alternative treatment. For unknown reasons a significant number of patients who take tetracycline exactly as directed do not respond to high dosages, whereas others respond very favorably to 250 mg once a day or once every other day and flare when attempts are made to discontinue treatment.
ADVERSE EFFECTS.
The incidence of photosensitivity to tetracycline is low, but it increases when higher dosages are used. All females should be warned about the increased incidence of Candida albicans vaginitis that occurs while taking antibiotics. The package labeling of oral contraceptives warns that reduced efficacy and increased incidence of breakthrough bleeding may occur with tetracycline and other antibiotics. Although this association has not been proven, it is prudent to inform patients of this potential risk. Pseudotumor cerebri, a self-limited disorder in which the regulation of intracranial pressure is impaired, is a rare complication of tetracycline treatment. Increased intracranial pressure causes papilledema and severe headaches. Increased intraocular pressure can lead to progressive visual impairment and eventually blindness.