Minocycline is a semi-synthetic tetracycline derivative which is well absorbed and distributed in body tissues and is suitable for twice daily administration. It appears to be as generally effective as other tetracyclines and analogues, but also to be effective in infections due to tetracycline-resistant staphylococci. Side-effects are typical of those of other tetracyclines, but minocycline has been associated with a high incidence of vertigo in some studies. On the other hand, minocycline appears to have little or no photosensitising potential. It is not yet clear whether minocycline can be safely used in patients with moderate or severe impairment of renal function, but if used in renal failure, the plasma urea concentration should be monitored.