Bethanechol

Early signs of overdosage are abdominal discomfort, salivation, flushing of the skin (“hot feeling”), sweating, nausea, and vomiting.

Atropine Sulfate is a specific antidote. The recommended dose for adults is 0.6 mg. Repeat doses can be given every two hours, according to clinical response. The recommended dosage in infants and children up to 12 years of age is 0.01 mg/kg (to a maximum single dose of 0.4 mg) repeated every two hours as needed until the desired effect is obtained or adverse effects of atropine preclude further usage. Subcutaneous injection of atropine is preferred except in emergencies when the intravenous route may be employed.

The oral LD50 of bethanechol chloride is 1510 mg/kg in the mouse.

Frequency Not Defined

Abdominal cramps

Belching

Borborygmi colicky pain

Bronchial constriction

Diarrhea

Flushing

Increased gastric motility

Headache

Hypotension

Lacrimation

Miosis

Nausea

Vomiting

Salivation

Urinary urgency

Before taking bethanechol, tell your doctor if you are taking any of the following medicines:

• donepezil (Aricept);

• tacrine (Cognex);

• quinidine (Cardioquin, others); or

• procainamide (Pronestyl, Procan SR).

You may not be able to take bethanechol, or you may require a dosage adjustment or special monitoring during treatment if you are taking any of the medicines listed above.

Drugs other than those listed here may also interact with bethanechol. Talk to your doctor and pharmacist before taking or using any other prescription or over-the-counter medicines.

• It is used to treat patients who are not able to pass urine the right way.
• It may be given to you for other reasons. Talk with the doctor.

General

In urinary retention, if the sphincter fails to relax as Bethanechol contracts the bladder, urine may be forced up the ureter into the kidney pelvis. If there is bacteriuria, this may cause reflux infection.

Information for Patients

Bethanechol chloride tablets should preferably be taken one hour before or two hours after meals to avoid nausea or vomiting. Dizziness, lightheadedness or fainting may occur, especially when getting up from a lying or sitting position.

Drug Interactions

Special care is required if this drug is given to patients receiving ganglion blocking compounds because a critical fall in blood pressure may occur. Usually, severe abdominal symptoms appear before there is such a fall in the blood pressure.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Long-term studies in animals have not been performed to evaluate the effects upon fertility, mutagenic or carcinogenic potential of Bethanechol chloride.

Pregnancy

Pregnancy Category C. Animal reproduction studies have not been conducted with Bethanechol chloride. It is also not known whether Bethanechol chloride can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Bethanechol chloride should be given to a pregnant woman only if clearly needed.

Nursing Mothers

It is not known whether this drug is secreted in human milk. Because many drugs are secreted in human milk and because of the potential for serious adverse reactions from Bethanechol chloride in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Pediatric Use

Safety and effectiveness in pediatric patients have not been established.

Dosage must be individualized, depending on the type and severity of the condition to be treated.

Preferably give the drug when the stomach is empty. If taken soon after eating, nausea and vomiting may occur.

The usual adult oral dose ranges from 10 to 50 mg three or four times a day. The minimum effective dose is determined by giving 5 to 10 mg initially and repeating the same amount at hourly intervals until satisfactory response occurs, or until a maximum of 50 mg has been given. The effects of the drug sometimes appear within 30 minutes and are usually maximal within 60 to 90 minutes. The drug effects persist for about one hour.

If necessary, the effects of the drug can be abolished promptly by atropine (see OVERDOSAGE).

A 1 mg/mL solution may be made with tablets. Crush twelve 10 mg tablets in a mortar and reduce to a fine powder. Add small portions of sterile water and mix to a uniform paste; mix while adding sterile water in incremental proportions to almost 120 mL; transfer to a calibrated bottle, rinse mortar with sterile water, and add quantity of sterile water sufficient to make 120 mL. Label “shake well” and “refrigerate”. Stable for 30 days (Schlatter, 1997).

A 5 mg/mL suspension may be made with tablets and either a 1:1 mixture of Ora-Plus® and Ora-Sweet® or Ora-Plus® and Ora-Sweet® SF or 1:4 concentrated cherry syrup and simple syrup, NF mixture. Crush twelve 50 mg tablets in a mortar and reduce to a fine powder. Add small portions of chosen vehicle and mix to a uniform paste; mix while adding the vehicle in incremental proportions to almost 120 mL; transfer to a calibrated bottle, rinse mortar with vehicle, and add quantity of vehicle sufficient to make 120 mL. Label “shake well” and “refrigerate”. Stable for 60 days refrigerated (preferred) or at room temperature (Allen, 1998; Nahata, 2004).

Concerns related to adverse effects:

• Reflux infection: If patient has bacteriuria, there is potential for reflux infection if the sphincter fails to relax as bethanechol contracts the bladder.

Bethanechol stimulates your bladder to empty.

Bethanechol is used to treat urinary retention (difficulty urinating), which may occur after surgery, after delivering a baby, and in other situations.

Bethanechol may also be used for purposes other than those listed in this medication guide.

Applies to bethanechol: compounding powder, oral tablet, subcutaneous solution

General

Adverse reactions occur more commonly following subcutaneous administration of bethanechol than with oral administration.

Cholinergic overstimulation with symptoms of circulatory collapse, fall in blood pressure, abdominal cramps, bloody diarrhea, shock, or sudden cardiac arrest has been reported rarely with subcutaneous administration of bethanechol. Atropine sulfate should be available to treat symptoms of toxicity when bethanechol is administered subcutaneously. The adult dose of atropine is 0.6 mg administered subcutaneously every 2 hours, according to patient response.[Ref]

Cardiovascular

Cardiovascular side effects have included decreased blood pressure with reflex tachycardia and vasomotor response.[Ref]

Nervous system

Nervous system side effects have included headache and seizure. Hypothermia has been reported. An acute dystonic reaction associated with the treatment of gastroesophageal reflux during bethanechol therapy in an infant has been reported.[Ref]

Gastrointestinal

Gastrointestinal side effects have included abdominal cramps, colicky pain, nausea, vomiting, diarrhea, salivation, and borborygmi.[Ref]

Ocular

Ocular side effects have included lacrimation and miosis.[Ref]

Renal

Renal side effects have included urinary urgency.[Ref]

Respiratory

Respiratory side effects have included aggravation of asthma and bronchial constriction.[Ref]

Dermatologic

Dermatologic side effects have included warmth/heat, flushing, and sweating. A case of miliaria crystallina associated with the use of bethanechol in a diabetic patient with autonomic bladder neuropathy has been reported.[Ref]

Some side effects of bethanechol may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Oral: 10 to 50 mg 3 to 4 times a day.

Subcutaneous: 2.5 to 5 mg 3 to 4 times a day. Doses up to 7.5 to 10 mg every 4 hours have been used for neurogenic bladder. Such large doses may cause severe reactions and should only be used after adequate trial of single doses (2.5 to 5 mg) has established that smaller doses are not sufficient.

Data not available