Fair response with partial improvement was noted in 37% of male patients and 34% of female patients. No response was reported in 10% of male and 8% of female IBS patients. There were few side effects noted with 8% reporting dry mouth. Dosages were reduced in patients who reported drowsiness (10%) as well as 1 patient who reported visual disturbance. Otherwise, the formulation was well tolerated. Donnatal also is a common component of a GI cocktail used in emergency rooms. In 1976, Donnatal was one of the 25 most widely prescribed drugs in the U.S. It has since been displaced by H2 antagonists and proton pump inhibitors, which are more effective and lack many of the adverse effects of phenobarbital.A four-week multicenter, randomized placebo-controlled trial by Turner et al. compared Donnatal® tablets (hyoscyamine sulfate - 0.1037 mg; atropine sulfate - 0.0194 mg; scopolamine hydrobromide - 0.0065 mg and phenobarbital - 16.2 mg) to belladonna alkaloids alone (hyoscyamine sulfate - 0.1037 mg; atropine sulfate - 0.0194 mg; scopolamine hydrobromide - 0.0065 mg), phenobarbital alone (16.2 mg) and placebo. The intent-to-treat population of 204 IBS patients was evaluated for pain (cramping), nighttime and daytime pain severity, bowel movement frequency, and with a clinician global evaluation of improvement in response to treatment. The response for improvement of pain was mixed for all groups after 1 day.
On September 29, 2011, the FDA issued new guidance with regard to the DESI category. This effectively disallowed any new DESI formulations to enter the market. The FDA also has stated that DESI drugs do not have any therapeutic equivalent drugs listed in the “Orange Book”. In their description of therapeutic equivalence, the FDA specifically cites Donnatal®. Therefore, any so-called generic drugs on the market with similar formulation to DESI drugs, are considered illegal drugs as the FDA has not reviewed their composition or therapeutic equivalence. Donnatal, although containing phenobarbital, is exempt from the Controlled Substances Act due to the belladonna alkaloids present in the formulation. References
External links
"Donnatal Extended Release Tablet Information". Archived from the original on 2008-12-27.