Drug Interactions

By:Robert Baird Baird




Tell your doctor or pharmacist if you are taking or if you are planning to take any over-the-counter or prescription medications or dietary supplements with gastrointestinal anticholinergics or antispasmodics. Doses of one or both drugs may need to be modified or a different drug may need to be prescribed. The following drugs and drug classes interact with gastrointestinal anticholinergics or antispasmodics.

Amantadine (eg, Symmetrel)

MAO Inhibitors (eg, Phenelzine)

Antacids (eg, Maalox)

Meperidine (eg, Demerol)

Anticholinergics, other (eg, bella donna alkaloids)

Metoclopramide (eg, Reglan)

Nitrates (eg, Nitroglycerin)

Benzodiazepines (eg, Diazepam)

Phenothiazines (eg, Promethazine)

Beta Blockers (eg, Atenolol)


Side Effects

Every drug is capable of producing side effects. Many anticholinergic or antispasmodic users experience no, or minor, side effects. The frequency and severity of side effects depend on many factors including dose, duration of therapy and individual susceptibility. Possible side effects include:

Digestive Tract: Nausea; vomiting; bloating; constipation; abdominal pain; appetite loss; difficulty swallowing.

Nervous System: Confusion; excitement; restlessness; hallucinations; headache; nervousness; drowsiness; dizziness; lightheadedness; tingling; numbness; difficulty moving; fainting; disorientation; short-term memory loss; slurred speech; incoordination; coma; exaggerated sense of well-being; decreased anxiety; tiredness; speech disturbance; weak­ness; sleeplessness; fever; tremor.

Circulatory System: Pounding in the chest (palpitations); fast or irregular heartbeat.

Respiratory System: Difficulty breathing; nasal stuffiness; nasal congestion.

Skin: Rash; itching; flushing; decreased sweating; hives; skin disorder.

Other: Difficult urination; muscle weakness; visual problems; blurred vision; dry mouth; taste changes; urinary retention; impotence; reduced breast milk production and flow; enlarged pupils; eye sensitivity to light; increased eye pressure.

Guidelines for Use

Take exactly as prescribed.


Take 30 minutes before meals. Take mepenzolate with meals and at bedtime.

If a dose is missed, take it as soon as possible. If several hours have passed or if it is nearing time for the next dose, do not double the dose to "catch up" (unless advised by your doctor). If more than one dose is missed or it is necessary to establish a new dosage schedule, contact your doctor or pharmacist.

May cause drowsiness, dizziness or blurred vision. Use caution when driving or performing other tasks requiring mental alertness, coordination or physical dexterity.

Notify your doctor if skin rash, flushing, rapid heartbeat, urinary retention, blurred vision or eye problems occur.

May cause dry mouth, difficulty in urination or constipation, or increased sensitivity to light. Notify your doctor if these effects persist or bec.ome severe.

If symptoms of fever, heatstroke and decreased sweating occur,discontinue the drug and contact a doctor immediately.

Signs of overdosage with these drugs include. Headache,nausea, vomiting, dizziness, dry mouth, blurred vision, rapid heartbeat rhythm, dry skin, fever, difficulty in swallowing, excitation tiredness stupor, coma, respiratory depression and paralysis doctor if these instances occur.

Avoid alcohol and medicines (eg, tranquilizers, that cause drowsiness.

Sucking on hard sugarless candy, drinking fluids and oral hygiene can relieve dry mouth.

Inform your doctor if you are pregnant, become to become pregnant or are breastfeeding.

Store at room temperature.

About the author:
The author also writes about precautions for drugs, uses and benefits of drugs and guidelines for using drugs.