Brand name: Donnatal

Generic name: It is a mixture of atropine, hyoscyamine, phenobarbitol, and scopolamine.

Preparation(s): tablet, liquid, suppositories

Uses for IBS
Donnatal is a mixture of atropine, hyoscyamine, phenobarbital and scopolamine, which means it has anticholinergic, antispasmodic, and sedative properties. Atropine, hyoscyamine, and scopolamine are anticholinergic agents and are used to decrease GI motility, or cramping, and for their antisecretory effects. Phenobarbital is a barbiturate agent used for its sedative actions. Donnatal has been around for the past 70 years and is currently being used to treat certain intestinal problems (irritable bowel syndrome, enterocolitis). It works by decreasing intestinal cramping and calming, or relaxing nerves.

The compounds atropine, hyoscyamine, scopolamine are active alkaloids found in the plant belladonna, which inhibit cholinergic and muscarinic receptors. These include the cholinergic receptors found in gastrointestinal and pulmonary smooth muscle, exocrine glands, the heart, and the eye. Blockage of the muscarinic receptors produce a reduction in salivary, bronchial, and sweat gland secretions; enlarged pupils; blurry vision; changes in heart rate; contraction of the bladder and gastrointestinal muscles, decreased gastric secretion; and decreased gastrointestinal motility. All three agents can inter the CNS, but scopolamine is the only one that causes CNS depression (drowsiness, euphoria, amnesia, fatigue, decreased REM sleep) at therapeutic doses.

Phenobarbital causes a sedative-hypnotic effect that lasts for several hours. However, other CNS effects, such as distorted judgment and impaired motor skills, can last for several days.

Because Donnatal is a mixture of several medications, it is contraindicated in situations where a drug-drug interaction may occur. The following drugs should not be taken in combination with Donnatal: potassium chloride, darunavir (HIV drug), pramlintide (Symlin, a diabetes drug), sodium oxybate (Xyrem or GHB), voriconazole (Vfen an antifungal drug), and etravirine (HIV drug).

Severe adverse reactions can occur if Donnatal is taken with: contraceptives, telithromycin (Ketek, an antibiotic), temsirolimus (anticancer drug), irinotecan (anticancer drug), posaconazole (Noxafil, an antifungal drug), erlotinib (Tarceva, anticancer drug), methoxyflurane (anesthetic), cyclosporine (immunosuppressant drug), and anticoagulants (heparin, warfarin, aspirin)

Adverse effects
The most frequent adverse effects are decreased sweating, dizziness, and drowsiness. Other less frequent effects are anxiety, blurred vision, reduction in breast milk, constipation, depression, fainting, headache, impaired cognition, insomnia, irritability, lethargy, nausea, nervousness, nightmares, vertigo, vomiting, and dry mouth.