bethanechol

Therapeutic Classification: urinary tract stimulant

Pharmacologic Classification: cholinergics

Indications ⬆ ⬇

REMS

Postpartum and postoperative nonobstructive urinary retention or urinary retention caused by neurogenic bladder.

Action ⬆ ⬇

Stimulates cholinergic receptors. Effects include:
- Contraction of the urinary bladder,
- Decreased bladder capacity,
- Increased frequency of ureteral peristaltic waves,
- Increased tone and peristalsis in the GI tract,
- Increased pressure in the lower esophageal sphincter,
- Increased gastric secretions.

Therapeutic effects:

Bladder emptying.

Pharmacokinetics ⬆ ⬇

Absorption: Poorly absorbed after oral administration.

Distribution: Does not cross the blood-brain barrier.

Metabolism/Excretion: Unknown.

Half-Life: Unknown.

Time/Action Profile ⬆ ⬇

(response on bladder muscle)

ROUTE	ONSET	PEAK	DURATION
PO	30–90 min	1 hr	6 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Mechanical obstruction of the GI or GU tract.

Use Cautiously in:

History of asthma;
Ulcer disease;
Cardiovascular disease;
Epilepsy;
Hyperthyroidism;
Sensitivity to cholinergic agents or effects;
OB: Lactation: Safety not established.

Adv. Reactions/Side Effects ⬆ ⬇

CV: bradycardia, HEART BLOCK, hypotension, SYNCOPE/CARDIAC ARREST

EENT: lacrimation, miosis

GI: vomiting, abdominal discomfort, diarrhea, nausea, salivation

GU: urgency

Neuro: headache, malaise

Resp: bronchospasm

Misc: sweating, flushing, hypothermia

Interactions ⬆ ⬇

Drug-drug:

Quinidine and procainamide may antagonize cholinergic effects.
Additive cholinergic effects with cholinesterase inhibitors.
Use with ganglionic blocking agents may result in severe hypotension.
Do not use with depolarizing neuromuscular blocking agents.
Effectiveness will be decreased by anticholinergics.

Drug-Natural Products:

Cholinergic effects may be antagonized by angel's trumpet, jimson weed, or scopolia.

Route/Dosage ⬆ ⬇

PO (Adults ): 25–50 mg 3 times daily. Dose may be determined by administering 5–10 mg every 1–2 hr until response is obtained or total of 50 mg administered or by starting with 10 mg, giving 25 mg 6 hr later, then, if needed, 50 mg 6 hr later.
PO (Children ): 0.2 mg/kg 3 times daily or 0.15 mg/kg 4 times daily.

Availability ⬆ ⬇

(Generic available)

Tablets: 5 mg; 10 mg; 25 mg; 50 mg

Assessment ⬆ ⬇

Monitor BP, pulse, and respirations before administering and for at least 1 hr after SUBQ administration.
Monitor intake and output ratios. Palpate abdomen for bladder distention. Notify health care professional if drug fails to relieve condition for which it was prescribed. Catheterization may be ordered to assess postvoid residual.

Lab Test Considerations:

May cause an increase in serum AST, amylase, and lipase concentrations.

Toxicity and Overdose:

Observe for drug toxicity (sweating, flushing, abdominal cramps, nausea, salivation). If overdose occurs, treatment includes atropine sulfate (specific antidote).

Implementation ⬆ ⬇

A test dose is usually employed before maintenance to determine minimum effective dose.
- Oral and SUBQ doses are not interchangeable.
PO: Administer medication on an empty stomach, 1 hr before or 2 hr after meals, to prevent nausea and vomiting.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication exactly as directed. Missed doses should be taken as soon as possible within 2 hr; otherwise, return to regular dosing schedule. Do not double doses.
Caution patient to change positions slowly to minimize orthostatic hypotension.
Advise patient to report abdominal discomfort, salivation, sweating, or flushing to health care professional.
Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

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Pronunciation ⬇

Classifications ⬆ ⬇