Background There are several studies at the international level analysing the cost of immunosuppressive treatment of kidney transplant patients. In Bulgaria pharmacotherapy of kidney transplant patients is provided by the hospital pharmacy and therefore it is important to know the amount paid for immunosuppression by the hospital providing the treatment.

Purpose To analyse the changes in the cost of pharmacotherapy for kidney transplant patients in Bulgaria during the period 2006–2011.

Materials and Methods A prospective cost study of the changes in pharmacotherapy of all adult kidney transplant patients in Bulgaria during the specified period. An analysis of prescribing practise was performed, cost of pharmacotherapy was calculated. Descriptive statistics and t-test analysis were performed to evaluate the changes in the prescribing practise and the cost of pharmacotherapy.

Results In total 21 therapeutic schemes were found prescribed. The number of patients on treatment varied for each year of the observation period because of patients dropping out of treatment. The total observed population for the period was 589 individuals. Most often, the prescribed therapeutic scheme was ciclosporin + mycophenolate; in 38% to 39% of all cases. A slow increase in the average monthly costs of pharmacotherapy was observed for the period 2007–2009, after which the cost declined from 172 EUR to 138 EUR per patient per month in 2010–2011. Those variations are mostly due to changes of pharmacotherapy. During the period 2007–2009 two new substances were introduced, tacrolimus and everolimus, which led to the increase in prescribing costs. For the period 2010–2011 generic immunosuppressants were introduced and the prescribing costs declined. The drug costs of kidney transplantation vary between 17.43% and 30.66% of the hospital’s drugs budget.

Conclusions To our knowledge this is the first Bulgarian study of prescribing practise and changes in the cost of drugs for kidney transplant patients. It reveals that prescribing costs are varying and dependent on the introduction of new molecules or generic products. The study shows that the introduction of the new immunosuppressive molecules leads to an increase in pharmacotherapy costs, while the introduction of generic products significantly reduces drug costs.

No conflict of interest.