Chronic intoxication by doxycycline use for more than 12 years.

We report the clinical case of a 12-years' intoxication by doxycycline. A patient with a depersonalization and derealization syndrome took 1 g doxycycline per day. In addition to hepatocellular necrosis with cholestasis, nephrotoxicity, leukopenia, anaemia and skin hyperpigmentation he suffered from hitherto unreported adverse cardiac events as intermittent supraventricular tachycardia and sporadic Wenckebach heart block. Despite a long period of self-medication these side-effects were reversible.