Donnatal was not pulled from the market for a single dramatic safety event. Instead, its story is more complicated: it has existed for decades in a regulatory gray area as an “unapproved” drug, and a combination of FDA enforcement pressure, safety concerns about one of its ingredients, and the availability of better alternatives has made it increasingly difficult to find. Many patients searching for Donnatal today are discovering that their pharmacy can no longer fill the prescription, or that the price has become prohibitively expensive.
Donnatal’s Unusual FDA Status
Donnatal is a combination of four active ingredients: phenobarbital (a barbiturate sedative), plus three belladonna alkaloids (hyoscyamine, atropine, and scopolamine) that work together to reduce intestinal muscle spasms and provide mild sedation. It has been prescribed for decades, primarily for irritable bowel syndrome and other gastrointestinal conditions involving cramping and spasm.
Here’s the part that surprises most people: Donnatal was never formally approved by the FDA. It predates the modern drug approval process. In 1962, Congress required the FDA to review the effectiveness of drugs that had already reached the market. This massive review effort, called the Drug Efficacy Study Implementation (DESI) program, flagged Donnatal under DESI proceeding 597 for anticholinergic/barbiturate combinations. That proceeding has never been finalized. The FDA’s own records list both Donnatal tablets and Donnatal Extentabs as part of open, unresolved DESI cases dating back to the mid-1970s.
Under FDA policy, drugs caught in these unresolved proceedings could remain on the market while the review was pending. For Donnatal, “pending” stretched across decades. The drug’s labeling on the National Library of Medicine’s DailyMed database carries a blunt disclaimer: “This drug has not been found by FDA to be safe and effective, and this labeling has not been approved by FDA.” Generic versions of the combination carry the same “unapproved drug” marketing status.
Why It Became Hard to Get
The FDA has periodically cracked down on unapproved drugs still circulating in the U.S. market. When the agency targets a category, manufacturers often stop production rather than invest in the expensive clinical trials needed to win formal approval. For a decades-old combination product like Donnatal, the economics rarely make sense: proving safety and efficacy through modern randomized trials costs hundreds of millions of dollars, and the drug’s patent protection expired long ago.
Supply disruptions and manufacturer decisions have made Donnatal increasingly scarce. When it is available, the cost reflects its niche status. Brand-name Donnatal tablets run around $1,436 for 100 tablets, or more than $14 per pill. The liquid formulation starts at roughly $430 for just 50 milliliters. Generic versions exist but have also faced availability problems, and the price gap between brand and generic has narrowed in ways that leave many patients paying far more than they expected.
Safety Concerns With Phenobarbital
Beyond the regulatory issues, Donnatal’s formulation raises safety flags that modern prescribing guidelines take seriously. Phenobarbital, the barbiturate component, is habit-forming. The drug’s own labeling warns that it should not be given to anyone with a history of physical or psychological dependence on drugs. Patients who take it regularly can develop tolerance and dependence, and abrupt withdrawal after habitual use can trigger delirium or seizures.
Phenobarbital also causes drowsiness and blurred vision significant enough that the labeling warns against driving or operating machinery. In some patients, it produces the opposite of its intended effect, causing restlessness or excitement rather than sedation. These risks are particularly concerning for a medication used to treat a chronic, non-life-threatening condition like IBS, where patients may take it daily for months or years.
Weak Evidence for IBS
The clinical evidence supporting Donnatal’s effectiveness is surprisingly thin. A review published through the National Institutes of Health noted that of the four active ingredients in Donnatal, only scopolamine has been studied in a controlled trial for IBS. The combination as a whole lacks the kind of rigorous, placebo-controlled data that modern drugs require.
The broader category of antispasmodic drugs for IBS has a mixed track record. A meta-analysis of 23 randomized controlled trials found that smooth muscle relaxants generally improved symptoms and reduced pain. But a second meta-analysis of 24 trials found that half the studies were negative. When researchers excluded lower-quality studies, very few individual antispasmodics held up as clearly effective for overall IBS symptom relief. Donnatal’s specific combination was not among those with strong evidence.
Alternatives Your Doctor May Suggest
If you’ve been taking Donnatal and can no longer get it, several FDA-approved options target the same symptoms without the barbiturate component. Hyoscyamine (one of Donnatal’s own ingredients) is available on its own as a standalone prescription, typically at 0.125 mg taken as needed up to four times daily, or in an extended-release form at 0.375 mg twice daily. It provides antispasmodic relief without the sedation and dependence risk of phenobarbital.
Dicyclomine is another widely prescribed antispasmodic that directly relaxes intestinal smooth muscle. It has a long track record and is available as an inexpensive generic. For patients whose IBS involves diarrhea, newer prescription options target the condition through different pathways entirely, working on serotonin receptors or bile acid absorption rather than simply blocking muscle contractions.
Peppermint oil capsules, taken in enteric-coated form so they dissolve in the intestines rather than the stomach, have shown benefit in controlled trials for IBS-related pain and cramping. They work through a similar smooth-muscle-relaxing mechanism and are available without a prescription. For many former Donnatal users, a combination of a modern antispasmodic plus dietary and lifestyle changes provides comparable or better symptom control without the risks of a barbiturate taken long-term.