ABSTRACT
The ability of erythromycin to inhibit the hepatic metabolism of carbamazepine causes carbamazepine toxicity. The severity of this drug interaction has been proposed to be related to the dose of erythromycin. The introduction of oral erythromycin produces a two- to fourfold increase in the carbamazepine serum concentration and the resultant toxic manifestations. Carbamazepine toxicity and a more marked increase in carbamazepine serum concentration were observed in a patient treated with intravenous erythromycin.
Subject(s)
Carbamazepine/adverse effects , Erythromycin/adverse effects , Adult , Drug Interactions , Erythromycin/administration & dosage , Humans , Injections, Intravenous , MaleABSTRACT
Among the various medications that have been associated with the development of syndrome of inappropriate antidiuretic hormone secretion (SIADH) are the tricyclic antidepressants. A 69-year-old man admitted for treatment of a depressive disorder that had not responded to trazodone was prescribed imipramine. Twenty-two days after initiation of therapy, the patient developed hyponatremia. The patient also had depressed serum osmolality and elevated urine sodium concentrations consistent with SIADH. With the discontinuation of imipramine, fluid restriction, and several doses of furosemide, normal serum sodium concentrations were attained. As antidepressant therapy was indicated, doxepin was selected. The patient maintained normal electrolyte values and water balance over the next two months of follow-up. No reports of doxepin-related SIADH were found in the literature; therefore, this agent may be considered as an alternative therapy in patients developing SIADH during antidepressant drug therapy.
