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Professional Information — Donnatal

Full FDA prescribing details for healthcare professionals.

Last updated · May 16, 2026Source: DailyMed ↗
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Highlights of Prescribing InformationRevised: Oct 17, 2011

Manufactured For:
PBM Pharmaceuticals, Inc.
Gordonsville, VA 22942

Manufactured By:
West-ward Pharmaceutical Corp.
Eatontown, NJ 07724 Revised June 2007

Indications and Usage

Based on a review of this drug by the National Academy of Sciences - National Research Council and/or other information, FDA has classified the following indications as “possibly” effective:

For use as adjunctive therapy in the treatment of irritable bowel syndrome (irritable colon, spastic colon, mucous colitis) and acute enterocolitis.

May also be useful as adjunctive therapy in the treatment of duodenal ulcer.  IT HAS NOT BEEN SHOWN CONCLUSIVELY WHETHER ANTICHOLINERGIC/ANTISPASMODIC DRUGS AID IN THE HEALING OF A DUODENAL ULCER, DECREASE THE RATE OF RECURRENCES OR PREVENT COMPLICATIONS.

Dosage and Administration

The dosage of Donnatal Extentabs® should be adjusted to the needs of the individual patient to assure symptomatic control with a minimum of adverse reactions. The usual dose is one tablet every twelve (12) hours.  If indicated, one tablet every eight (8) hours may be given.

Contraindications

Glaucoma, obstructive uropathy (for example, bladder neck obstruction due to prostatic hypertrophy); obstructive disease of the gastrointestinal tract (as in achalasia, pyloroduodenal stenosis, etc.); paralytic ileus, intestinal atony of the elderly or debilitated patient; unstable cardiovascular status in acute hemorrhage; severe ulcerative colitis especially if complicated by toxic megacolon; myasthenia gravis; hiatal hernia associated with reflux esophagitis.

Donnatal Extentabs® is contraindicated in patients with known hypersensitivity to any of the ingredients.  Phenobarbital is contraindicated in acute intermittent porphyria and in those patients in whom phenobarbital produces restlessness and/or excitement.

Adverse Reactions

Adverse reactions may include xerostomia; urinary hesitancy and retention; blurred vision; tachycardia; palpitation; mydriasis; cycloplegia; increased ocular tension; loss of taste sense; headache; nervousness; drowsiness; weakness; dizziness: insomnia; nausea; vomiting; impotence; suppression of lactation; constipation; bloated feeling; musculoskeletal pain; severe allergic reaction or drug idiosyncrasies, including anaphylaxis, urticaria and other dermal manifestations; and decreased sweating. Acquired hypersensitivity to barbituates consists chiefly in allergic reactions that occur especially in persons who tend to have asthma, urticaria, angioedema and similar conditions. Hypersensitivity reactions in this category include localized swelling, particularly of the eyelids, cheeks, or lips, and erythematous dermatitis.  Rarely, exfoliative dermatitis (e.g. Stevens-Johnson syndrome and toxic epidermal necrolysis) may be caused by phenobarbital and can prove fatal. The skin eruption may be associated with fever, delirium, and marked degenerative changes in the liver and other parenchymatous organs. In a few cases, megaloblastic anemia has been associated with the chronic use of phenobarbital. Elderly patients may react with symptoms of excitement, agitation, drowsiness, and other untoward manifestations to even small doses of the drug.

Phenobarbital may produce excitement in some patients, rather than a sedative effect.  In patients habituated to barbiturates, abrupt withdrawal may produce delirium or convulsions.

Overdosage

The signs and symptoms of overdose are headache, nausea, vomiting, blurred vision, dilated pupils, hot and dry skin, dizziness, dryness of the mouth, difficulty in swallowing, and CNS stimulation. Treatment should consist of gastric lavage, emetics, and activated charcoal.  If indicated, parenteral cholinergic agents such as physostigmine or bethanechol chloride should be added.

Description

Each Donnatal Extentabs® tablet contains:

Phenobarbital, USP (3/4 gr.)    48.6 mg
Hyoscyamine Sulfate, USP    0.3111 mg
Atropine Sulfate, USP    0.0582 mg
Scopolamine Hydrobromide, USP    .0.0195 mg

Each Donnatal Extentabs® tablet contains the equivalent of three Donnatal® tablets. Extentabs are designed to release the ingredi¬ents gradually to provide effects for up to twelve (12) hours.

In addition, each tablet contains the following inactive ingredients: Anhydrous Lactose, Calcium Sulfate Granular, Colloidal Silicon Dioxide, Dibasic Calcium Phosphate, Lactose Monohydrate, Magnesium Stearate, and Stearic Acid. Film Coating and Polishing Solution contains: D and C Yellow #10 Aluminum Lake, FD and C Blue #1 Aluminum Lake, Hydroxypropyl Methylcellulose, Polydextrose, Polyethylene Glycol, Titanium Dioxide, and Triacetin.  The printing ink contains Titanium Dioxide.

How Supplied / Storage and Handling

Donnatal Extentabs® Tablets are supplied as: film coated green, round, compressed tablets printed “P421” in black ink.

Bottles of 100 tablets
Bottles of 500 tablets

Store at 20-25°C (68-77°F) [See USP Controlled Room Temperature].  Protect from light and moisture.

Dispense in a well-closed, light-resistant container as defined in the USP using a child-resistant closure.

Also available: Donnatal® Tablets in bottles of 100 and 1000 tablets and Donnatal® Elixir in 4 fl oz bottles and 1 pint bottles.

Sources

RxCUI: 1046999

Last fetched: May 16, 2026

Source: DailyMed ↗

⚠️ Disclaimer

This information is for educational purposes only and is not medical advice. Always consult your doctor, pharmacist, or other licensed healthcare professional before starting, stopping, or changing any medicine. Read full medical disclaimer.