Background
Clinical trial protocols provide specific guidelines regarding the use of concomitant medications and complementary medicines. Patients enrolled in an oncology clinical trial are often taking multiple medicines for other co-morbidities. Experience with investigational medicines(s) may be limited and there may be safety concerns due to potential drug-drug interactions manifesting in reduced efficacy or increased toxicity. Clinical trial pharmacists are highly skilled in answering protocol specific medication-related enquiries and often receives ad-hoc requests from clinical trial nurses or doctors, however, this process does not systematically capture all at-risk patients and comprehensive medication lists are not provided.

Aims
To describe the type and complexity of medication-related enquiries for patients who are planned or enrolled in a clinical trial.

Methods
Clinical trial medication-related enquiries received by pharmacy over a 19 week period (31/3/2015 – 10/8/2015) were recorded and classified according to type and complexity, and whether an intervention occurred. All enquiries were assessed for possible interaction or compliance with concomitant medication requirements.

Results
Overall, a total of 42 enquiries, involving 98 medications were received by pharmacy. On average 25 minutes was spent reviewing each request. 95% of enquiries received were from hospital staff members. 20% of enquiries related to complimentary medicines. 35% of enquiries resulted in a recommendation by pharmacy to change therapy. 66% of the interventions made by pharmacy were considered high-risk due to either potential toxicity or protocol violation which could result in jeopardising patient enrolment in the clinical trial.

Conclusions
This work highlights that there is an unmet need for trial patients who would benefit from having a clinical trials pharmacist available to review all of their medications. Moving forward there is potential to expand the clinical trials pharmacist role to provide a pharmacy service in outpatient clinics where clinical trial patients can be referred for review.