Patients' perspective on their drug therapy after bariatric surgery: A quantitative, cross-sectional interview study.

Drug therapy in patients who have undergone bariatric surgery is challenging. We aimed to investigate the patients' perspective on their drug therapy. This should allow deriving tailored measures to better support patients and their healthcare professionals with drug therapy after bariatric surgery. We conducted a quantitative telephone-based interview study with patients who have undergone bariatric surgery. The interview consisted of assessments in three parts: (i) current drug therapy: prescription, administration and adherence, (ii) changes after bariatric surgery and (iii) adverse events. (i) The 105 enrolled patients were taking a median of 10 (range: 3-30) drugs. In 1017 of 1080 drugs (94%), expectations in drug effectiveness were (rather) met. Of the 105 patients, 27% reported difficulties in drug administration, 44% forgot to take their drugs at least one time and 20% reported deviations from the prescription. (ii) Sixteen percent of the patients observed changes in drug effectiveness or tolerability-additionally to therapy adjustment by physicians. (iii) Seventy-four percent recognised at least one adverse event right before and/or after bariatric surgery, most frequently in gastrointestinal disorders. Patients who have undergone bariatric surgery have to deal with many difficulties in drug handling and adverse events. Our study emphasises the need for better and more individual support for patients with their drug therapy after bariatric surgery and, therefore, suggests a multidisciplinary approach that includes pharmacists. The stronger involvement of the patients' perspective seems to be a valuable source in research and practice.