Evaluation of oral antidepressant drugs for adaptation to the simple suspension method

Objective: Gavage administration of antidepressant drugs is required for some depressed patients with dysphagia. In the recent years, a simple suspension method has drawn increasing attention as a method that prevents changes in the stability and safety of various drugs. However, only 59 of the 354 orally administered antidepressant drugs (16.7%) approved in Japan by April 2013 have been examined with this method. In this study, we investigated whether 44 oral antidepressant drugs, which have not previously been tested for effi cacy through gavage, could be adapted to the simple suspension method. Materials and Methods: Adaptability of antidepressants to the simple suspension method was assessed by incubating at room temperature a drug in 20 mL of warm water (at 55°C) in a 30 mL-syringe for 5 and 10 min. The ability of the decayed drugs to pass through the tubing was also examined. Results: Most of the 44 oral antidepressant drugs tested could be adapted to the simple suspension method. Unexpectedly, fl uvoxamine maleate tablets, milnacipran hydrochloride tablets, and Cymbalta® capsules required 10 min or longer to decay. Conclusion: We were able to qualitatively assess all 44 oral antidepressant drugs. These results provide useful information for administration of oral antidepressant drugs to depressed patients using a simple suspension method. Key words: Difficulty swallowing, gavage administration, generic drugs, oral antidepressant drugs, simple suspension method.