Role of the Pharmacist in Managing Antidepressant Drug Interactions in the Solid Organ Transplant Population

In transplant patients, Major Depressive Disorder (MDD) is the most prevalent psychiatric disorder and is associated with reduced quality of life, with prevalence rates of MDD in up to 25% of solid organ transplant (SOT) patients [1]. MDD can lead to medication nonadherence, which can cause rejection of the transplant organ. Additionally, antidepressant medications have a range of unique side effects and potential for pharmacokinetic and pharmacodynamic interactions. Many of the transplant medications are metabolized by cytochrome P450 3A4 enzymes, putting them at risk for pharmacokinetic drug interactions. In addition, these medications can have pharmacodynamic interactions with antidepressants. Corticosteroids can cause weight gain, leading to diabetes and obesity. Cyclosporine causes hypertension in 50% of kidney transplant patients. Tacrolimus and cyclosporine have been reported to have central nervous toxicity in one-third of patients. Corticosteroids, sirolimus, and cyclosporine have been associated with hyperlipidemia [2]. Hence, these interactions with antidepressants can result in altered concentrations of immunosuppressants or additive untoward side effects (Table 1).