propylthiouracil and Drug-Overdose

6-Mercaptopurine (6-MP), although an effective immunosuppressive when used in the treatment of certain cancers, can have devastating effects when ingested accidentally or used in excessive amounts. We report here the case of an unintentional ingestion of a large amount of 6-MP by a woman with hypothyroidism who was erroneously given this antimetabolic agent by her pharmacist instead the propylthiouracil (PTU) she was actually prescribed. This is one of several documented cases in which 6-MP has been dispensed instead of PTU. Because of the myelosuppressive and hepatotoxic effects of 6-MP, this case reinforces the need for both physicians and patients to understand the importance of examining their medications before ingestion.

Topics: Adult; Antimetabolites, Antineoplastic; Antithyroid Agents; Blepharoptosis; Drug Overdose; Female; Humans; Hyperthyroidism; Medication Errors; Mercaptopurine; Propylthiouracil

Topics: Abdominal Pain; Adolescent; Antithyroid Agents; Diagnosis, Differential; Drug Overdose; Female; Gastrointestinal Hemorrhage; Glomerular Mesangium; Graves Disease; Humans; IgA Vasculitis; Propylthiouracil; Vasculitis, Leukocytoclastic, Cutaneous; Vomiting

Clinical studies in thyrotoxicosis reveal a state of high bone turnover leading, eventually, to osteoporosis. Recently there has been concern that thyroxine (T4) treatment may have a similar effect on bone. Rat models have been used to study the effects of T4 on bone, but the majority of studies have looked at the effects of T4 after only 3 weeks of treatment. The aim of this study was to evaluate histomorphometric changes in rats after 12 weeks of thyroxine overtreatment or 12 weeks of hypothyroidism compared with untreated control animals. Animals received either T4 200 micrograms/kg per day, 0.1% propylthiouracil, or vehicle for 12 weeks. Tetracycline was administered 1 week and 3 weeks prior to killing. Iliac crest bone was used for histomorphometry. Serum T4 measurements (taken at killing) confirmed hyper- and hypothyroidism in the appropriate animal groups (between group difference p < 0.001 by ANOVA). In hyperthyroid animals there was an increase in mineral apposition rate (MAR; 0.94 vs. 0.59 microns/day, p < 0.001) and mineral formation rate (MFR/BS; 0.24 vs. 0.12 x 10(-2) micron3/micron2 per day, p < 0.001) and a slight increase in eroded surfaces (ES/BS%; 1.54 vs. 1.36, p < 0.05) compared with controls, consistent with previous in vitro and in vivo observations. In hypothyroid rats there was a marked reduction in osteoid surfaces (OS/BS%; 1.7 vs. 24.8, p < 0.001) and MAR (0.3 vs. 0.59 micrograms/day, p < 0.001), a reduction in ES/BS% (0.51 vs. 1.36, p < 0.05), and an increase in cancellous bone volume (BV/TV%; 30.29 vs. 19.6, p < 0.05), suggesting that thyroid hormones are a requirement for normal bone turnover.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Analysis of Variance; Animals; Body Weight; Calcinosis; Disease Models, Animal; Drug Overdose; Hyperthyroidism; Hypothyroidism; Ilium; Male; Propylthiouracil; Radioimmunoassay; Rats; Rats, Wistar; Tetracycline; Thyroid Function Tests; Thyroxine

Topics: Drug Overdose; Propylthiouracil; Thiouracil