Probable Interaction between Trazodone and Carbamazepine

Abstract

The need to maintain long-term treatment of chronic pathologies makes the appearance of interactions possible when such therapies incorporate other drugs to deal with the aggravation of the same or other intercurrent pathologies. A case is presented in which the addition of trazodone to a chronic treatment with carbamazepine (CBZ) is associated with symptoms typical for intoxication by this antiepileptic, accompanied by a raised serum concentration. When the trazodone was suspended, these symptoms lessened and the concentration of CBZ decreased progressively, suggesting a probable interaction between the 2 drugs.

Key words

carbamazepine - trazodone - drug interaction

References

• 1 Horn JR, Hansten PD, Chan LN. Proposal for a new tool to evaluate drug interaction cases.  Ann Pharmacother. 2007;  41 674-680
• 2 Karch FE, Lasagna L. Toward the operational identification of adverse drug reactions.  Clin Pharmacol Ther. 1977;  21 247-254
• 3 Leite SAO, Leite PJM, Rocha GA. et al . Carbamazepine kinetics in cardiac patients before and during amiodarone.  Arq Neuropsiquiatr. 1994;  52 210-215
• 4 Naranjo CA, Busto U, Sellers EM. et al . A method for estimating the probability of adverse drug reactions.  Clin Pharmacol Ther. 1981;  30 239-245
• 5 Otani K, Ishida M, Kaneko S. et al . Effects of carbamazepine coadministration on plasma concentration of trazodone and its active metabolite, m-chloro-phenylpiperazine.  Ther Drug Monit. 1996;  18 164-167
• 6 Sánchez-Romero A, García-Delgado R, Flores-Peña M. Interaction between trazodone and carbamazepine.  Ann Pharmacother. 1999;  33 1370

Correspondence