Lymecycline is a prodrug which is metabolized to tetracycline (active metabolite) and excreted in active form in urine. Tetracycline have shown to be a substrate and an inhibitor of CYP3A4, but this is probably to a minor degree and clinically insignificant. Tetracycline is not listed as an inducer or a mechanism-based inhibitor of any CYP enzymes. Lymecycline is therefore not suspected to be porphyrinogenic. Side effects such as nausea, vomiting and diarrhoea may be potentially porphyrinogenic through reduction in carbohydrate intake.

Broad spectrum antibiotic with alkyl amino group.

Lymecycline is indicated for the treatment of tetracycline sensitive aerobe and anaerobe Gram-positive and Gram-negative microorganisms. Nausea, vomiting and diarrhoea are reported as very common side effects.

Lymecycline is a prodrug which undergoes hydrolysis to tetracycline and inactive metabolites when it passes through the intestinal wall. Tetracycline is a substrate for P-glycoprotein (Kim 2002) and 60% of administered oral dose is excreted in active form in urine. Elimination half-life is 10-12 hours. In vitro studies have shown that tetracycline is a substrate and an inhibitor of CYP 3A4 (Zhao 1997, 1999). Tetracycline is not listed as a mechanism-based inhibitor or an inducer of CYP enzymes. In vivo studies have shown no interaction between tetracycline and oral contraceptives (Murphy 1991), indicating that the inhibition of CYP 3A4 is not clinically significant.

Thunell: A few observations of tolerance.