Generic Name: BELLADONNA ALKALOIDS/PHENOBARBITAL - ORAL
Pronounced: (bell-a-DON-a al-KA-loyd/FEE-noe-BAR-bi-tal)

Donnatal Oral Interactions

See also the How to Use section.

The effects of some drugs can change if you take other drugs or herbal products at the same time. This can increase your risk for serious side effects or may cause your medications not to work correctly. These drug interactions are possible, but do not always occur. Your doctor or pharmacist can often prevent or manage interactions by changing how you use your medications or by close monitoring.

To help your doctor and pharmacist give you the best care, be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products) before starting treatment with this product. While using this product, do not start, stop, or change the dosage of any other medicines you are using without your doctor's approval.

Some products that may interact with this drug include:

• etravirine
• potassium tablets/capsules
• rilpivirine
• sodium oxybate
• drugs that are affected by slowed gut movement (such as metoclopramide, pramlintide)

This medication may affect the absorption of other products such as levodopa, griseofulvin, certain azole anti-fungal drugs (ketoconazole, itraconazole), slowly dissolving forms of digoxin, among others.

Many other drugs that also cause dry mouth and constipation may interact with anticholinergics/antispasmodics such as belladonna alkaloids. Tell your doctor or pharmacist about all the products you take, including:

• amantadine
• other anticholinergic drugs (such as atropine, glycopyrrolate, scopolamine)
• other antispasmodic drugs (such as clidinium, dicyclomine, hyoscyamine, propantheline)
• certain drugs used to treat Parkinson's disease (such as benztropine, trihexyphenidyl)
• certain drugs used to treat irregular heart rhythms (such as disopyramide, quinidine)
• MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, selegiline, tranylcypromine)
• phenothiazines (such as chlorpromazine)
• tricyclic antidepressants (such as amitriptyline)

Other medications can affect the removal of phenobarbital from your body, which may affect how this product works. Examples include disulfiram, drugs to treat seizures (such as phenytoin, valproic acid), St. John's wort, among others.

Phenobarbital can speed up the removal of many other medications from your body, which may affect how they work. Examples of affected drugs include cyclosporine, doxycycline, estrogens, metronidazole, ranolazine, "blood thinners" such as warfarin, corticosteroids such as prednisone, calcium channel blockers such as felodipine/nimodipine, among others.

This medication may decrease the effectiveness of hormonal birth control such as pills, patch, or ring. This could cause pregnancy. Discuss with your doctor or pharmacist if you should use additional reliable birth control methods while using this medication. Also tell your doctor if you have any new spotting or breakthrough bleeding, because these may be signs that your birth control is not working well.

Tell your doctor or pharmacist if you are taking other products that cause drowsiness or slow/shallow breathing including alcohol, antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants, and narcotic pain relievers (such as codeine).

Check the labels on all your medicines (such as allergy or cough-and-cold products, diet aids) because they may contain ingredients that cause drowsiness or a fast heartbeat. Ask your pharmacist about using those products safely.

This medication may interfere with certain laboratory tests (including gastric secretion tests), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.

This document does not contain all possible drug interactions. Keep a list of all the products you use. Share this list with your doctor and pharmacist to lessen your risk for serious medication problems.

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