Bethanechol

Bethanechol is used to help the bladder empty when it can't do so on its own. Bethanechol Chloride Tablets are approved for:

• Acute postoperative urinary retention — difficulty urinating after surgery, when there's no physical blockage
• Postpartum urinary retention — difficulty urinating after childbirth, when there's no physical blockage
• Neurogenic atony of the urinary bladder with retention — weak bladder muscle caused by nerve damage or dysfunction, leading to an inability to empty the bladder normally

Bethanechol works by mimicking the body's parasympathetic nervous system — the system that, among other things, signals the bladder to contract and empty. It activates the same receptors that the natural chemical acetylcholine would, causing the bladder muscle (called the detrusor) to tighten and squeeze. Unlike acetylcholine, bethanechol isn't broken down quickly by the body's enzymes, so its effects last longer and are more predictable.

Bethanechol focuses mainly on smooth muscle in the bladder and digestive tract. At normal doses, it has little effect on heart rate, blood pressure, or the brain — it doesn't cross the blood-brain barrier.

Bethanechol Chloride Tablets are taken by mouth, typically three or four times a day. The dose is tailored to the individual — your prescriber will find the lowest amount that works for you.

• Take on an empty stomach when possible; food — especially a recent meal — can trigger nausea and vomiting
• Effects usually begin within 30 minutes and peak within 60 to 90 minutes
• Each dose generally lasts about one hour

Always follow your prescriber's instructions and the directions on your label. Do not adjust your dose without checking first.

Most side effects with the oral tablet are uncommon, but they become more likely if the dose is too high. Common ones include:

• Nausea, belching, or vomiting (most often if taken with food)
• Abdominal cramps or colicky pain
• Diarrhea
• Flushing or warmth in the face
• Sweating
• Increased saliva
• Headache
• Urinary urgency

More serious reactions — such as wheezing or an asthma attack, a sudden drop in blood pressure with a racing heart, or a seizure — require immediate medical attention. Contact your doctor or emergency services right away if these occur.

• Do not use if there is any blockage in the bladder or digestive tract, or if you recently had bladder or bowel surgery — stimulating muscle contractions in these situations can be dangerous.
• Asthma: bethanechol can trigger bronchospasm (airway tightening) and asthma attacks. It should not be used by people with active or latent asthma.
• Heart and blood pressure conditions: bethanechol can lower blood pressure and should not be used in people with coronary artery disease, low blood pressure, slow heart rate, or unstable blood pressure.
• Other conditions where it must be avoided: hyperthyroidism, peptic ulcer, epilepsy, Parkinson's disease, and peritonitis (abdominal inflammation).
• Overdose: if too much is taken, atropine sulfate is the specific antidote. Early signs of too much include abdominal discomfort, heavy sweating, flushing, nausea, and vomiting — seek help immediately.

Bethanechol has a known interaction with one important class of medications:

• Ganglion-blocking drugs (older medications sometimes used for high blood pressure): taking these together with bethanechol can cause a severe, dangerous drop in blood pressure. Severe abdominal symptoms typically appear as a warning sign just before the pressure falls. Your care team should be aware of all medications you take.

This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.

• Tell your prescriber if you have or have ever had asthma — even if it is mild or not currently active
• Tell your prescriber if you have hyperthyroidism (overactive thyroid) or a peptic ulcer
• Tell your prescriber if you have coronary artery disease, a slow heart rate (bradycardia), low blood pressure, or unstable blood pressure
• Tell your prescriber if you have epilepsy or Parkinson's disease
• Do not take bethanechol if you have a physical blockage in your bladder or bowel, or if you've recently had surgery on your bladder, stomach, or intestines
• Do not take if you have peritonitis (abdominal inflammation), bladder neck obstruction, or acute inflammatory bowel disease
• Tell your prescriber about all prescription and over-the-counter medications you take, especially blood pressure drugs

Taking too much bethanechol can cause abdominal discomfort, heavy sweating, flushing (hot skin), nausea, vomiting, and increased saliva — these are the early warning signs. Atropine sulfate is the specific antidote and should be given by a medical professional. If you think you or someone else has taken too much, seek emergency medical care immediately.

Bethanechol stimulates the parasympathetic nervous system, producing effects similar to acetylcholine but more sustained. Its main therapeutic action is tightening the bladder's detrusor muscle enough to trigger urination. It also increases tone and movement in the stomach and intestines. At therapeutic doses by mouth, it has little measurable effect on heart rate, blood pressure, or circulation, and it does not affect the brain because it cannot cross the blood-brain barrier.

When taken by mouth, bethanechol's effects can begin within 30 minutes, but maximum effect usually takes 60 to 90 minutes. A typical oral dose lasts about one hour, though very large doses have been reported to produce effects for up to six hours. Unlike acetylcholine, bethanechol is not broken down by the enzyme cholinesterase, which is why its effects are more prolonged. The body's exact process for metabolizing and clearing bethanechol has not been fully worked out.

Store at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) . Dispense in a tight container as defined in the USP. Keep out of reach of children.