Background: The aims of this study are to find the prevalence of potential drug-drug interactions (DDIs) in patients with Hemodialysis and identify factors associated with these interactions if present.

Methods: The study was an observational- retrospective cohort study that was conducted in ten hemodialysis units in the West bank, Palestine, between June and August 2015. The data collection form was completed by interviewing the patients in addition to reviewing their medical records. Potential DDIs were reviewed. SPSS program was used for data analysis.

Results: The study included 275 patients, a total of 930 potential interactions were identified in 245 (89.1 %) patients. Patients were prescribed 1-15 drugs with a mean (± SD) of 7.87 ± 2.44, calcium carbonate was the most common drug prescribed. The most common potential interaction in 114 (41.5 %) patients was Calcium Carbonate/Amlodipine followed by Calcium Carbonate/Aspirin in 76 (27.6 %) cases. Most patients (89.9 %) of the patients had one or more comorbid diseases; hypertension, diabetes and gout were the most common. Univariate analysis showed that the number of potential DDIs were related to the number of diseases, the number of prescribed drugs (P value <0.0001) and the age of the patient (P value = 0.015). The results of multiple linear regression showed a significant positive association between number of potential DDIs with the total number of medications (r = 0.242; p < 0.001).

Conclusion: The prevalence of potential drug- drug interactions among hemodialysis patients is very common; they are highly expected and depend on the number of drugs taken by the patients. Many of these potential interactions are considered as preventable drug- related problems, so screening for potential interactions and monitoring regularly is highly needed.