Long-term use of tetracycline

We recently saw a 21-year-old woman who died of tetracycline-associated fatty liver at 38 weeks of pregnancy and in whom we demonstrated gross and microscopic fluorescence of tetracycline in bone. Tissue extraction and quantitative chemical analysis showed 60 mg of tetracycline per gram of wet bone tissue. Initially, we could elicit no history of tetracycline ingestion from the patient's records and family. Approximately eight months after the death of the patient, a nurse who had taken care of her related that the patient's husband had once told her that the patient had been using tetracycline for acne. However, she had suspended its use during pregnancy. This case points out the possibility that tetracycline may be released from the bone after its incorporation there in the remote past and that it might cause hepatotoxicity in a vulnerable woman at the time of pregnancy. The drug may be stored in the bone in the form of loose complexes with calcium apatite and protein matrix. Such conditions as pregnancy, hyperparathyroidism, acidosis, and osteomalacia might cause bone turnover and the drug molecules may be chelated and released in sufficient quantities to damage an already vulnerable liver.