It is surprising how high the nonadherence rates for immunosuppressants is among renal transplant recipients, ranging from 15 to 40%, despite the potential impact of nonadherence and the degree of education provided to transplant recipients.
Nonadherence to immunosuppressive medications is associated with increased incidences of allograft rejection and a seven-fold increased risk of graft failure as compared to adherent patients. Approximately 20-25% of nonadherent renal transplant recipients develop a late rejection at five years posttransplant, frequently antibody-mediated, as compared to 5-8% of adherent patients. Even a short period of nonadherence to immunosuppressive medications can initiate the rejection process.
Identifying possible barriers to adherence and intervening accordingly is necessary for improving transplant outcomes. One of the well-studied barriers is the complexity of the immunosuppressive regimen. Choosing a simpler regimen among possible effective regimens is likely to provide convenience to patients and; therefore, improve adherence. In addition, forgetfulness is one of the most common causes of missed doses. Nonadherence is more prevalent in patients with comorbidities that can cause impaired cognitive function.
Some interventions to improve adherence include: associating medication administration times with a daily activity (such as meals, waking up, or going to bed), using pill boxes, and setting alarms or voice reminders that help patients remember to take their medications at the right times.
Ineffective communication may also increase the probability of intentional nonadherence due to a poor understanding of the benefits and risks associated with the patients’ prescribed medications. Most medications used in the transplant setting are preventive, and patients do not perceive the benefits of the medications immediately, which may facilitate nonadherence. Although fear of developing side effects can complicate patients’ nonadherence, patients are more likely to be adherent to a medication when they are aware of its possible adverse effects, which highlights the importance of educating patients. High drug costs can limit patients’ access to medications and increase nonadherence rates. Even with Medicare part B coverage, there are significant copays for patients without secondary insurance. Also, even if patients have prescription drug coverage, the high number of medications needed for some transplant patients can result in high monthly out-of-pocket expenses. This ongoing financial burden is substantial for most patients, and could act as a barrier to adherence when it is not addressed and adjusted.
It is imperative for renal transplant recipients to adhere to medication regimens, as it can directly affect outcomes. Clinicians should assess adherence at every follow-up and keep in mind possible barriers to medication adherence, in particular, complexity of regimen, financial burden and lack of knowledge of potential consequences of nonadherence.
Miae Kim, PharmD, PGY2 Resident in Transplant Pharmacy
Steven Gabardi PharmD, FCCP, BCPS, Organ Transplant Clinical Specialist at BWH