What is Donnatal?
Donnatal is a brand-name prescription drug that contains four active ingredients: the barbiturate phenobarbital and three belladonna alkaloids—hyoscyamine, atropine, and scopolamine. These components work together to treat specific gastrointestinal issues and are available in both tablet and liquid (elixir) forms. The medication provides a mild sedative effect from phenobarbital and antispasmodic action from the belladonna alkaloids.
How Donnatal Works
Donnatal's effectiveness comes from the combined actions of its ingredients. The belladonna alkaloids are anticholinergic and antispasmodic agents that block acetylcholine, a neurotransmitter involved in muscle contractions and secretions in the digestive system. This action helps relax stomach and intestinal muscles, slow gut movement, and reduce secretions, thereby alleviating cramping, spasms, and discomfort associated with conditions like IBS. Phenobarbital, a barbiturate sedative, acts on the central nervous system to provide a calming effect, which can be helpful for patients whose gastrointestinal symptoms are influenced by stress or anxiety.
Medical Uses
Donnatal is used as an adjunctive, or supplementary, treatment for certain gastrointestinal disorders. Its approved uses include managing symptoms of Irritable Bowel Syndrome (IBS), acute enterocolitis, and potentially duodenal ulcers, although its effectiveness for ulcer healing is considered “possibly effective” by the FDA.
Donnatal vs. Bentyl: A Comparison
Donnatal and Bentyl (dicyclomine) are both used for IBS treatment, but they differ in composition and effects.
| Feature | Donnatal (phenobarbital/belladonna alkaloids) | Bentyl (dicyclomine) |
|---|---|---|
| Composition | Combination of a barbiturate (phenobarbital) and three anticholinergics (hyoscyamine, atropine, scopolamine). | Single anticholinergic agent (dicyclomine). |
| Mechanism | Anticholinergic/antispasmodic and mild sedative effects. | Specifically blocks acetylcholine to relax smooth muscle in the gut. |
| FDA Status | Marketed before effectiveness laws; rated "possibly effective.". | FDA approved for the treatment of IBS. |
| Dependence Risk | Contains phenobarbital, which can be habit-forming. | Not known to be habit-forming. |
| Sedative Effect | Provides a mild sedative effect due to phenobarbital. | No sedative effect. |
| Common Side Effects | Dry mouth, blurred vision, dizziness, constipation, drowsiness. | Dry mouth, dizziness, blurred vision. |
| Cost | Can be more expensive, though generics are available at a lower cost. | Available as a lower-cost generic. |
Potential Side Effects and Risks
Donnatal can cause various side effects due to its ingredients.
Common side effects
Common side effects include dry mouth, blurred vision, dizziness, drowsiness, constipation, and reduced sweating.
Serious side effects and warnings
Serious risks include dependence and severe withdrawal symptoms if stopped suddenly, particularly due to the phenobarbital content. It can also increase the risk of heatstroke because it reduces sweating. Donnatal is not recommended during pregnancy as it may harm the fetus and can make hormonal birth control less effective. It is contraindicated in individuals with conditions like glaucoma, urinary or intestinal obstruction, myasthenia gravis, or severe ulcerative colitis.
Important Precautions and Interactions
It is crucial to discuss your medical history and all current medications with your doctor before taking Donnatal.
Medical history
Conditions to inform your doctor about include glaucoma, prostate problems, heart issues, liver or kidney disease, myasthenia gravis, porphyria, and a history of substance dependence.
Drug interactions
Donnatal can interact with many medications. Phenobarbital can reduce the effectiveness of blood thinners like warfarin and hormonal contraceptives. Combining Donnatal with alcohol, opioids, or other sedatives can increase drowsiness and breathing difficulties. Antacids should be taken at least 2 hours apart from Donnatal as they can affect its absorption.
Conclusion
Donnatal is a combination prescription medication used as an adjunctive therapy for conditions like IBS, acute enterocolitis, and duodenal ulcers. It contains phenobarbital for a sedative effect and belladonna alkaloids for antispasmodic action. While it can help manage symptoms, it carries risks such as dependence and various side effects. Its use requires careful consideration of contraindications, potential drug interactions, and strict medical supervision.
For more detailed prescribing information and FDA labeling, refer to the official DailyMed page(https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=11a48ba9-576b-4e8c-9536-6e83636d6930).
