Generic ingredients: Phenobarbital with hyoscyamine sulfate, atropine sulfate, and scopolamine hydrobromide.

Other brand names: Barophen, Donnamor, Donnapine, Donna-Sed, Hyosophen, Malatal, Myphentol, Relaxadon, Spaslin, Spasmophen, Susano.

Donnatal is an anticholinergic/antispasmodic. It slows the action of the bowel and reduces the amount of stomach acid. 

Quick Facts About Donnatal


Used to treat cramps and stomach, intestinal, and bowel pain.

Donnatal Dosage

Take 1/2 hour to 1 hour before meals, as prescribed.

  • Usual adult dose: tablets or capsules — 1 or 2 tablets or capsules 3 or 4 times per day. Liquid — 1 or 2 teaspoonfuls 3 or 4 times per day. Donnatal Extentabs — 1 tablet every 8 or 12 hours as prescribed by your doctor.
  • Usual child dose: elixir is determined by body weight. Usual dosage is given every 4 to 6 hours.
  • Missed dose: take as soon as possible, unless almost time for next dose. In that case, do not take missed dose: go back to regular schedule. Do not double doses.

Donnatal Side Effects

Overdose symptoms:

blurred vision, central nervous system stimulation, difficulty swallowing, dilated pupils, dizziness, dry mouth, headache, hot and dry skin, nausea, vomiting. If you suspect an overdose, immediately seek medical attention.

More common side effects: agitation, allergic reaction, bloated feeling, blurred vision, constipation, decreased sweating, difficulty sleeping, difficulty urinating, dilation of the pupil of the eye, dizziness, drowsiness, dry mouth, excitement, fast or fluttery heartbeat, headache, hives, impotence, lessened sense of taste, muscular and bone pain, nausea, nervousness, rapid heartbeat, skin rash or hives, suppression of lactation, vomiting, weakness.

No known less common or rare Donnatal side effects.


Inform your doctor before combining Donnatal with:

antidepressants such as Elavil and Tofranil; antihistamines such as Benadryl; antispasmodics such as Bentyl and Cogentin; barbiturates such as Seconal; blood thinners such as Coumadin; diarrhea medications that contain either kaolin or attapulgite; digitalis (Lanoxin); MAO inhibitors such as Nardil and Parnate; narcotics such as Percocet; potassium supplements (Slow-K or K-Dur); steroids such as Medrol and Deltasone; tranquilizers such as Valium. Take antacids at least 1 hour before taking Donnatal.

Donnatal can intensify the effects of alcohol; check with your doctor before using alcohol. 

Special Cautions

If pregnant or planning to become pregnant, inform your doctor immediately. Not known if Donnatal appears in breast milk.

No special precautions apply to seniors.

Follow doctor’s instructions carefully for children.

  • Do not take if you have been drug dependent; Donnatal contains phenobarbital, which can be habit-forming.
  • Do not take if you have: glaucoma, diseases that block the urinary or gastrointestinal tract, or myasthenia gravis.
  • May cause drowsiness and impair your ability to drive a car or operate machinery. Do not take part in any activity that requires alertness.
  • Avoid use if you have: acute intermittent porphyria, hiatal hernia, intestinal atony, severe ulcerative colitis, or unstable cardiovascular status, or if phenobarbital makes you excited instead of calm.
  • Should not take if sensitive or allergic to this or similar medications.
  • Use with caution if you have: gastric ulcer, heart disease, high blood pressure, irregular or rapid heartbeat, kidney or liver disease, or overactive thyroid.
  • Monitor for heat prostration when in high temperatures, Donnatal can decrease sweating.
  • If you experience diarrhea, contact your doctor immediately, especially if you have an ileostomy or colostomy.

Note: provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Donnatal side effects, please contact your healthcare provider.