Minocycline: Side Effects
See also Tetracyclines
Minocycline, in common with doxycycline, is more lipo-philic than other tetracyclines. It is well absorbed after oral administration. Its half-life is 16-18 hours. Its higher affinity for fatty tissues improves its effectiveness and changes its adverse effects profile. Local gastrointestinal irritation and disturbance of the intestinal bacterial flora occur less often than with the more hydrophilic drugs, which have to be given in higher oral doses for sufficient absorption.
Nevertheless, its toxic effects are similar to those of other tetracyclines and arise from accumulation in fatty tissues. Accumulation in a third compartment and the resulting long half-life may contribute to an increased incidence of various toxic adverse effects during long-term treatment, even if lower daily doses are used. This seems also to be the case for pigmentation disorders and possibly for neurological disturbances.
Minocycline is predominantly eliminated by the liver and biliary tract (70-90%). Therefore, no change in dose is needed in patients with impaired renal function. However, it should be considered that hepatic elimination of doxycycline might be accelerated by co-administration of agents that induce hepatic enzymes.
Adverse effects of minocycline are reported far more often than adverse effects of other tetracycline derivatives. Whatever the mechanisms underlying this larger number of reports might be, they continue to appear. With increasing use of minocycline in acne and other conditions, adverse reactions may become increasingly common; early recognition is important to prevent further deterioration, to hasten recovery, and to avoid invasive investigations and treatment. The authors of this review recommended that safer alternatives be considered in the treatment of acne.
Minocycline: Organs and Systems
Susceptibility Factors
Renal disease
Minocycline is almost completely eliminated via the liver and the biliary tract and is therefore safe in patients with pre-existing renal insufficiency.
Drug Administration
Drug administration route
The use of minocycline as an agent for inducing chemical pleurodesis has been reported in only a few patients and there is little information regarding its adverse effects. In a retrospective study, 51 patients with primary spontaneous pneumothorax treated by video-assisted thoracoscopic surgery followed by instillation of minocycline hydrochloride 7 mg/kg into the pleural space through a thoracostomy tube were compared with 51 who underwent surgery only. Chest pain was a common complaint after minocycline pleurodesis, but the total doses of analgesics were comparable. The rate of prolonged air leaks was significantly lower after minocycline (7 versus 18%). Patients treated with minocycline had shorter periods of postoperative chest drainage and hospitalization. The ipsilateral recurrence rate was also significantly lower (2.9 versus 9.8%).
Drug-Drug Interactions
Phenothiazines
Black galactorrhea was described in a breastfeeding woman during treatment with minocycline and a phenothiazine.