Difficult to swallow: patient preferences for alternative valproate pharmaceutical formulations

To determine the degree to which swallowing valproate (VP) tablets is an issue, the proportion of patients who would prefer an alternative formulation, and the predictors of preference.

A quantitative telephone survey of eligible adults (n = 400, >/=18 years old) who currently take (n = 236) or previously took (n = 164) VP tablets within the past 6 months was conducted.

More than half of the patients indicated that VP tablets were 'uncomfortable to swallow' (68.5%, n = 274) and were 'very interested' (65.8%, n = 263) in medications that were easier to swallow. When choosing conceptually between taking VP tablet once/day or an equally safe and effective but significantly smaller soft gel capsule twice per day, the 82.8%, (n = 331) preferred the soft gel capsule. In the multivariate regression analysis, perceiving soft gel capsules to be easier to swallow (OR = 73.54; 95% CI = 15.01 to 360.40) and taking VP more frequently (OR = 2.02; 95% CI = 1.13 to 3.61) were significant predictors of soft gel capsule treatment preference.

VP users would prefer a formulation that is easier to swallow, even if it is needed to be taken twice per day. When choosing between medications with similar efficacy and safety, physicians can consider patient preferences to optimize conditions for medication adherence.