Jeremy is a 66-year-old man who was scheduled to have surgery for a recurring kidney cancer. Jeremy needed surgery to operate on the cancer. Before the end of the procedure, he was given tramadol intravenously to help manage postoperative pain.
In the recovery room, Jeremy was in severe pain and was given two more doses of tramadol within 35 minutes. After 10.5 hours, Jeremy was unresponsive, had abnormally slow breathing, narrow pupils and was not reacting to painful stimuli.
A pharmacogenetic test revealed that Jeremy was an ultra-rapid metabolizer of tramadol, meaning that he had an increased conversion of tramadol to morphine and had a higher risk of side effects when taking tramadol. The morphine was over-accumulating in his blood stream causing him to have an adverse drug reaction.
Crews, K.R. et al. (2012) Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines for codeine therapy in the context of cytochrome P450 2D6 (CYP2D6) genotype. Clin Pharmacol Ther 91, 321-6.
PharmGKB. Dutch Pharmacogenetics Working Group Guideline for tramadol and CYP2D6. https://www.pharmgkb.org/guideline/PA166104959. Accessed October, 2013.
Stamer, U.M. et al. (2008) Respiratory depression with tramadol in a patient with renal impairment and CYP2D6 gene duplication. Anesth Analg 107, 926-9.