Chapter 25: Cholinergic Drugs prepu

A client who has been prescribed bethanechol asks a nurse to explain how the drug works. What would be a correct response?

"Bethanechol is a direct-acting cholinergic drug that causes contraction of the smooth muscles of the bladder and passage of urine." Explanation: Bethanechol is a direct-acting cholinergic drug that causes contraction of the smooth muscles of the bladder and passage of urine. Bethanechol is not an indirect acting cholinergic drug nor is it a diuretic. It does not increase water production in the kidneys; kidneys do not produce water

Which statement made by a client who has been prescribed varenicline indicates an understanding of the planned smoking cessation program?

"I need to get involved in a support program as a part of my therapy." Explanation: The client should pick a date to stop smoking, begin the drug 1 week before that date, and quit smoking between days 8 and 35 of the treatment plan. The drug therapy should be part of a complete support and education program. If the client has not been able to stop smoking in 12 weeks, the drug should be stopped. The treatment regimen can be restarted after factors that prevented success are addressed.

A nursing student is trying to remember what the parasympathetic branch of the autonomic nervous system does. The nurse would provide which of the following statements as the best reminder?

"It is the rest-and-digest response." Explanation: The parasympathetic branch of the autonomic nervous system is known as the rest-and-digest response because activation of the parasympathetic nervous system causes heart rate to slow, pulmonary bronchioles to constrict, blood vessels to dilate (causing increased blood flow to GI tract), increased salivation, smooth muscles of bladder to contract, and pupils to constrict. Neither contract-and-relax response nor sink-or-swim response are valid responses. Fight-or-flight response is used to describe the sympathetic nervous system.

A client is reading something about his medication on the Internet and asks the nurse what synergistic means. What would be a correct response by the nurse?

"This occurs when two drugs are taken together and the effect is greater than the two drugs taken separately." Explanation: Synergistic means that when two drugs are taken together the effects of the drugs are greater than the effect of the two drugs taken separately.

A physician has prescribed 5mg IV of edrophonium to a client with myasthenia gravis. The available dose is 4 mL/40 mg. How much of edrophonium should the nurse administer the client?

0.5 mL Explanation: The nurse should administer 0.5 mL of edrophonium to the client.

A nurse caring for a client receiving bethanechol for urinary retention should advise the client that voiding usually occurs how long after oral administration?

30 to 90 minutes Explanation: A nurse caring for a client receiving bethanechol (Urecholine) for urinary retention should advise the client that voiding usually occurs 30 to 90 minutes after an oral dose is administered. The time frame of 5 to 15 minutes does not allow enough time for the medication to be absorbed and distributed. The time frame of 2 to 4 hours indicates that the medication will not work and the time frame of 12 to 24 hours indicates that the client will have bladder distention and that an insertion of a catheter may need to be placed to relieve the pressure exerted on the bladder.

When preparing to administer a cholinergic drug, the nurse understands that which is responsible for activating the primary neurotransmitter in the parasympathetic nervous system?

Acetylcholinesterase Explanation: Acetylcholinesterase is the enzyme responsible for activating acetylcholine, the primary neurotransmitter in the parasympathetic nervous system. DNA gyrase is a bacterial enzyme that catalyzes the breaking and rejoining of bonds of DNA strands. Protease is a group of enzymes that catalyze the hydrolytic degradation of proteins or polypeptides to smaller amino acid polymers. Lipase is enzyme that breaks down fats, produced by the liver, pancreas, and other digestive organs.

A 40-year-old, diagnosed with myasthenia gravis (MG), is scheduled to begin treatment with oral neostigmine. When providing relevant health education, the nurse should emphasize that successful control of MG symptoms will primarily depend on what personal behavior?

Adhering strictly to the prescribed administration schedule Explanation: Strict adherence to timely medication administration promotes optimal blood levels of neostigmine and optimal symptom control. Doses are not typically matched to short-term symptom severity, except in emergencies. Lifestyle modifications and acceptance may be of benefit, but pharmacologic therapy is of paramount importance in the treatment of MG.

Decreased acetylcholine levels are characteristic of what disorder?

Alzheimer's disease. Explanation: In normal brain function, acetylcholine is an essential neurotransmitter and plays an important role in cognitive functions, including memory storage and retrieval. Alzheimer's disease, the most common type of dementia in adults, is characterized by acetylcholine abnormalities. Multiple sclerosis (MS) is a disease of the central nervous system. Protecting the nerve fibers of the central nervous system is a fatty tissue called myelin, which helps nerve fibers conduct electrical impulses. In MS, myelin is lost in multiple areas, leaving scar tissue called sclerosis. Huntington's disease is a genetic neurologic disorder characterized by abnormal body movements called chorea and a lack of coordination; it also affects a number of mental abilities and some aspects of behavior. There is no specific test or marker for Parkinson's disease (PD); diagnosis is by a health care provider and depends on the presence of at least two of the three major signs: tremor at rest, rigidity, and bradykinesia, as well as the absence of a secondary cause, such as antipsychotic medications or multiple small strokes in the regions of the brain controlling movement.

Which agent would be used to counteract a severe reaction occurring with the use of neostigmine?

Atropine Explanation: Atropine is used to counteract the severe effects of an indirect acting cholinergic agonist. Naloxone is used to reverse opioid toxicity. Edrophonium is used as the antidote for nondepolarizing NMJ blockers. Phentolamine is used as treatment for extravasation of IV norepinephrine or dopamine

A client being treated for myasthenia gravis is receiving neostigmine. When the client's pulse drops to 50 after the administration, which medication should be administered to treat the bradycardia?

Atropine Explanation: Atropine will reverse the muscarinic effects of cholinergic crisis, including bradycardia. Neither pseudoephedrine nor propranolol will affect the bradycardia. Bethanechol will likely increase the bradycardia.

The health care provider is preparing to administer edrophonium to confirm myasthenia gravis in a 47-year-old male client. What other drug must be available when edrophonium is administered?

Atropine Explanation: Edrophonium is a cholinergic agonist administered by a provider to diagnose myasthenia gravis. Use of this drug requires that an antidote, typically atropine, be on hand in case of cholinergic overdose.

An adult client with a recent history of visual disturbances and dysphagia has just been diagnosed with myasthenia gravis. The nurse should recognize that this client's health problem is ultimately attributable to what pathophysiologic process?

Autoimmune destruction of acetylcholine receptors Explanation: Myasthenia gravis occurs when antibodies produced by the body's own immune system block, alter, or destroy the receptors for acetylcholine at the neuromuscular junction, which prevents muscle contraction from occurring. The disease does not involve dopamine deficits, demyelination, or excess anticholinesterase.

A nurse is reviewing the medication history of several clients. One of the clients is receiving a direct-acting cholinergic drug. The nurse would identify which drug?

Bethanechol Explanation: Bethanechol is an example of a direct-acting cholinergic that acts like the neurotransmitter acetylcholine. Pyridostigmine, guanidine, and ambenonium are indirect-acting muscle stimulants.

The client has been diagnosed with urinary retention. The nurse expects the client to receive which medication for this condition?

Bethanechol Explanation: Bethanechol is the only medication listed that is used to treat urinary retention. Ambenonium and guanidine are used to treat myasthenia gravis. Benadryl is an antihistamine.

The client is receiving a cholinergic agonist. Which assessment finding in a client warrants immediate action by the nurse?

Blood pressure decreased from 110/90 mm Hg to 80/50 mm Hg Explanation: A client receiving a cholinergic agonist is at risk for hypotension and bradycardia. Increased urination is a therapeutic effect of the medication and is not cause for immediate concern. One loose stool is not a cause for concern. Hypotension is a concern and could be caused by the medication.

A nurse is caring for a 49-year-old client who has been taking bethanechol for treatment of neurogenic bladder. After one week, the client develops sweating, heavy salivation, and bronchospasm. What would the nurse suspect is happening with this client?

Cholinergic crisis Explanation: Overdose of cholinergic agonists can lead to cholinergic crisis. Symptoms of cholinergic crisis are those associated with excessive stimulation of the parasympathetic nervous system, including increased sweating, salivation, gastric secretions, and respiratory secretions. If not treated quickly, cholinergic crisis can lead to respiratory failure. It does not lead to myasthenic crisis, or pulmonary edema. With any medication there can be anaphylactic reaction, but these symptoms do not indicate that.

A nurse observing a client receiving treatment with pyridostigmine for myasthenia gravis notices the client clenching the jaw, salivating excessively, and experiencing muscle weakness, rigidity, and spasm. The nurse interprets these as indicating which of the following?

Cholinergic crisis Explanation: Symptoms of cholinergic crisis include severe abdominal cramping, diarrhea, excessive salivation, muscle weakness, rigidity and spasm, and clenching of the jaw. In acetylcholinesterase crisis, a pronounced muscular weakness and respiratory paralysis caused by excessive acetylcholine, often a result of overmedication with anticholinesterase drugs. Hypertensive emergency includes retinal hemorrhage, increased intracranial pressure resulting in headache and/or vomiting, and kidney organ failure. Status epilepticus is a medical emergency and can be of different types and caused by brain trauma, infection, or stroke.

A 32-year-old breast-feeding mother has been diagnosed with closed-angle glaucoma and is receiving cholinergic therapy. She does not have a history of asthma, cardiovascular disease, or biliary disorder. What is the most important factor that the nurse would consider during ongoing assessment of the therapy?

Cholinergic stimulation in her infant Explanation: The therapy for closed-angle glaucoma should be continuously assessed for cholinergic stimulation in the patient's infant. If such stimulation occurs, the drug should be discontinued immediately. The assessment for cholinergic stimulation would include assessing for an increase in the airway resistance, bronchial secretions, and stimulation of sphincters; these are all cholinergic effects. It would not be advisable to assess only one of these factors. Therefore, assessing for cholinergic stimulation is the best answer

A client with a neurogenic bladder secondary to a spinal tumor has been taking bethanechol. When the nurse finds the client anxious, diaphoretic, and visibly flushed, what action should the nurse take to best assure the client's safety?

Contact the health care provider as the client may be experiencing a cholinergic crisis. Explanation: The presence of sweating and skin flushing in a client taking bethanechol is suggestive of a cholinergic crisis. This is a medical emergency that warrants prompt intervention by the care team. This problem is not treated with epinephrine. Assessing the client's bladder or inserting a Foley catheter is not sufficient.

The client is receiving Bethanechol for bladder atony. What assessment findings indicate the effect of this medication?

Increased urinary output Explanation: This medication is used to treat bladder atony and urinary retention, so an increased urinary output will be seen. The medication will not have an effect on RBCs, blood pressure, or hemoglobin.

The client is to receive an IV cholinergic medication. When the nurse administers the drug what reaction will the nurse anticipate?

Decrease in heart rate Explanation: Cholinergic drugs decrease, not increase, heart rate. They do not usually have any effect on anxiety

The client has been prescribed a cholinergic medication. Which nursing diagnosis is common for clients taking a cholinergic medication?

Diarrhea related to medication side effect Explanation: Diarrhea is a common side effect/nursing diagnosis when taking a cholinergic medication. Weight gain, sleep disturbance, and constipation are not common side effects/nursing diagnoses that relate to taking a cholinergic medication.

After teaching a group of nursing students about drugs used for myasthenia gravis, the instructor determines that the teaching was successful when the students identify which drug as being used to diagnose this condition?

Edrophonium Explanation: Edrophonium is used to diagnose myasthenia gravis. Pyridostigmine, guanidine, and ambenonium are used to treat myasthenia gravis.

A nurse would be alert for which risk if a client was receiving a cholinergic drug and then was ordered to receive another cholinergic drug?

Greater risk for toxicity Explanation: There can be greater risk for toxicity if a client is being administered a cholinergic drug with other cholinergics. Increased risk of CNS depression, greater risk for cardiac symptoms, and risk of hypertension and dyskinesia are not risks that may occur if a client is being administered a cholinergic drug with other cholinergics.

The nurse administers a drug that will increase micturition. What should the nurse assess for a therapeutic effect?

Increased voiding Explanation: Micturition is another term for urination; therefore, medications given to increase micturition should increase voiding.

A client diagnosed with myasthenia gravis is administered a cholinergic drug named neostigmine. How does this drug produce its therapeutic effect?

It stimulates the parasympathetic nervous system. Explanation: As a cholinergic drug, neostigmine stimulates the parasympathetic nervous system. It does not stimulate the sympathetic nervous system, cardiac system, or respiratory system.

A nurse administers carbachol eye drops to a client. What would indicate that the drug is effective?

Miosis Explanation: Miosis or pupil constriction would be an expected effect of carbachol. Mydriasis is pupil dilation and this is not an expected effect of carbachol. Carbachol does not cause drooping (ptosis) of the eyelid. Carbachol does not affect the eye muscles.

The stimulation of which of the following receptors in the parasympathetic nervous system stimulates smooth muscle? (Choose one)

Muscarinic receptors Explanation: The stimulation of muscarinic receptors in the parasympathetic nervous system stimulates smooth muscle.

A client is diagnosed with Eaton-Lambert disease and is given a prescription for guanidine. For which of the following known adverse reactions to guanidine should the nurse monitor the client?

Numbness in lips and extremities Explanation: Guanidine is a drug used to treat Eaton-Lambert disease. Adverse reactions to guanidine include: palpitations, numbness in lips and extremities, dry mouth, nausea, and abdominal cramping. Headache, hypotension, hypertension, constipation, and cold extremities are not common adverse reactions.

The nursing instructor is discussing cholinergic drugs with his clinical group. What system would the instructor tell the students is stimulated by cholinergic drugs?

Parasympathetic nervous system Explanation: Cholinergic agonists act at the same site as the neurotransmitter acetylcholine (ACh) and increase the activity of the ACh receptor sites throughout the body. Because these sites are found extensively throughout the parasympathetic nervous system, their stimulation produces a response similar to what is seen when the parasympathetic system is activated.

A nursing student is preparing to administer the drug bethanechol to a client with urinary retention. After researching the drug's actions and uses, the student demonstrates understanding of the drug by identifying it as which type of medication? Select all that apply.

Parasympathomimetic drug Cholinergic drug Bethanechol is an example of a parasympathomimetic drug because it mimics the activity of the parasympathetic nervous system. Bethanechol is a cholinergic drug that mimics the activity of the parasympathetic nervous system. An adrenergic blocker interferes with the action of the sympathetic nervous system. A sympatholytic drug blocks or inhibits the action of the sympathetic nervous system.

After teaching a group of students about the effects of cholinergic agents, the instructor determines that the teaching was successful when the students identify what as an effect?

Pupil constriction Explanation: Cholinergic agents cause pupil constriction. Increased salivation is an effect of cholinergic agents. Decreased heart rate is an effect of cholinergic agents. Increased bladder muscle tone is an effect of cholinergic agents

After teaching a group of nursing students about the effects of the parasympathetic nervous system, the instructor determines the need for additional teaching when the students identify which of the following?

Slowing of peristalsis Explanation: Stimulation of the parasympathetic nervous system leads to the following: blood vessels dilate, sending blood to the gastrointestinal (GI) tract; secretions and peristalsis are activated and salivary glands increase production; the heart slows and pulmonary bronchioles constrict; and the smooth muscle of the bladder contracts and the pupils of the eyes constrict.

A client has been prescribed topical cholinergic drug therapy for treatment of glaucoma. The nurse would inform the client that which effect might occur when beginning therapy?

Temporary decrease in visual sharpness and headache Explanation: The nurse should inform the client that a temporary reduction of visual acuity (sharpness) and headache may occur at the beginning of the therapy. Nausea, increased salivation, abdominal cramping and diarrhea, and flushing of the skin are adverse reactions associated with cholinergic drugs not administered topically.

The nurse is caring for a client diagnosed with Sjögren's syndrome and is receiving pilocarpine 5 mg PO t.i.d. What assessment finding represents the desired outcome?

The client denies having a dry mouth. Explanation: Pilocarpine is indicated for treatment of Sjögren's syndrome to treat dry mouth. It is not used to prevent vision loss, reflux, or cognitive decline.

The nurse is assessing a client who received pyridostigmine. What assessment indicates a potential side effect?

The client has a heart rate of 55 beats/minute. Explanation: Side effects to pyridostigmine include cardiac arrhythmias, specifically bradycardia. The other symptoms are not potential side effects.

The client has been prescribed a cholinergic agonist. Which statement is true concerning the administration of cholinergic agonists?

The parasympathetic nervous system is stimulated by these medications. Explanation: The parasympathetic nervous system is stimulated by these medications. Acetylcholine is the substance that transmits nervous impulses across the parasympathetic branch of the autonomic nervous system. The sympathetic nervous system is not stimulated by these medications and they are administered frequently.

Which best reflects the action of direct acting cholinergic agonists?

They occupy receptor sites for acetylcholine. Explanation: Direct acting cholinergic agonists occupy receptor sites for acetylcholine on the membranes of effector cells. Indirect acting cholinergic agonists react chemically with acetylcholinesterase to prevent it from breaking down acetylcholine. Indirect acting cholinergic agonists react chemically with acetylcholinesterase to prevent it from breaking down acetylcholine. Cholinergic agonists in general are often called parasympathomimetic because their action mimics that of the parasympathetic nervous system.

The nurse administered neostigmine to a client with myasthenia gravis. The nurse is doubling the dose that the client was taking at home. Three hours later, the nurse is assessing the client and notes the following symptoms: nausea with vomiting, diarrhea, and sweating. What does the nurse interpret these symptoms to be?

This is cholinergic crisis, and the provider needs to be notified immediately. Explanation: This would not be an idiosyncratic reaction. This is an adverse reaction but requires the nurse to take immediate action. The symptoms can be the result of a cholinergic crisis or of a myasthenic crisis. The fact that the dosage was increased would result in a cholinergic crisis.

The client is ordered bethanechol subcutaneously. After giving the client the injection of bethanechol, the nurse should make sure that what is available?

Urinal, bed pan, and call light Explanation: Bethanechol subcutaneous injections are used to relax the bladder so a client with urinary retention can void. After giving a client a subcutaneous injection, the client will usually need to void within about 15 minutes, so it is important the client has a way to easily void. Magazines, books, computers, sunglasses, eye mask, and vomit bags are not needed after administration of subcutaneous bethanechol.

A 78-year-old client is admitted to the Emergency Department (ED) and is diagnosed with bradycardia. The client tells the nurse that the client is taking donepezil (Aricept), a cholinergic agent, for Alzheimer's disease. The nurse knows that the drug of choice for bradycardia is:

atropine. Explanation: Maintain atropine sulfate on standby as an antidote in case of overdose or severe cholinergic reaction.

The health care provider is preparing to write a prescription for a client diagnosed with urinary retention. Which medication does the nurse expect to be prescribed?

bethanechol Explanation: Bethanechol is a sympathomimetic agent that acts at the cholinergic receptors in the urinary and GI tracts to increase muscle tone. The increased tone of the detrusor muscle in the urinary bladder allows for bladder emptying. Neostigmine and ambenonium are used to treat myasthenia gravis. Donepezil is used to treat Alzheimer's disease.

The nurse in the pediatric unit is caring for an infant who has been diagnosed with gastroesophageal reflux. What medication, if ordered, would the nurse administer to treat this condition?

bethanechol Explanation: Only bethanechol is indicated for the treatment of esophageal reflux in infants and children. The other drugs treat intraocular pressure, dry mouth, or to allow surgeons to perform certain surgical procedures.

The emergency department has been alerted to the impending arrival of several clients following possible exposure to sarin gas. The nurse knows that sarin causes harm through what process?

excessive cholinergic stimulation Explanation: Sarin is a toxic nerve gas that produces a cholinergic crisis characterized by excessive cholinergic (muscarinic) stimulation and neuromuscular blockade. This cholinergic crisis occurs because the irreversible anticholinesterase poison binds to the enzyme anticholinesterase and inactivates it. Consequently, acetylcholine remains in cholinergic synapses and causes excessive stimulation of muscarinic and nicotinic receptors. Sarin does not eliminate or distort acetylcholine nor does it cause excessive dopamine stimulation.

A nurse is writing a plan of care for a client who has been prescribed bethanechol. What outcome should the nurse include in the care plan?

improved bladder function Explanation: Bethanechol is prescribed for nonobstructive urinary retention and neurogenic bladder. The appropriate outcome for this client would be improved bladder function. This drug causes pupillary constriction and increased secretions. This drug would not increase blood pressure. However, it could cause hypotension in the older client.

The nurse is assessing a client who has been prescribed a cholinergic agonist. The nurse should recognize that the therapeutic effects of this medication are due to what process?

increased activity of acetylcholine receptor sites throughout the body Explanation: Cholinergic agonists are drugs that increase the activity of acetylcholine receptor sites throughout the body. Dopamine, GABA, and norepinephrine are not associated with cholinergic agonist function.

The nurse is caring for a client who has been diagnosed with myasthenia gravis and has administered a prescribed dose of pyridostigmine. The nurse assesses for an improvement in the client's status, which results from what action?

inhibiting the action of acetylcholinesterase Explanation: Indirect-acting cholinergic agonists such as pyridostigmine work by reversibly blocking acetylcholinesterase at the synaptic cleft. This blocking allows the accumulation of ACh released from the nerve endings and leads to increased and prolonged stimulation of ACh receptor sites. These drugs do not directly stimulate receptors or increase ACh release.

A client is prescribed the direct-acting cholinergic agonist bupropion to aid in smoking cessation. For which other prescribed medication should the nurse question giving the client bupropion?

metoprolol Explanation: Bupropion hydrochloride is a prescription medication that has a formulation used as an antidepressant and a different formulation to aid in smoking cessation. It may act by weakly inhibiting the neuronal reuptake of norepinephrine and dopamine; however, the exact mechanism of how it helps with smoking cessation is not entirely known. The doses of bupropion of medications metabolized by CYP2D6 enzymes should be reduced when taking with bupropion due to bupropion inhibiting CYP2D6. A medication that should be reduced includes metoprolol. Digoxin, tamoxifen, and furosemide are not contraindicated when taking bupropion.

The nurse administers a dose of carbachol to an ophthalmologic client. When assessing this client, the nurse would expect to see effects arising from stimulation of what receptors?

muscarinic Explanation: The direct-acting cholinergic agonists are similar to acetylcholine (ACh) and react directly with receptor sites to cause the same reaction as if ACh had stimulated the receptor sites. These drugs usually stimulate muscarinic receptors within the parasympathetic system. Carbachol is used as an ophthalmic agent to induce miosis to relieve the increased intraocular pressure of glaucoma. They have no effect on alpha- and beta-receptors in the sympathetic nervous system and less impact on nicotinic receptors than muscarinic receptors.

The nurse is caring for a client who has indirect-acting cholinergic agonists prescribed to treat myasthenia gravis. When administering this classification of drug, the nurse should assess the client for what sign of a potential toxic effect?

muscle weakness Explanation: The client with a cholinergic crisis presents with progressive muscle weakness and respiratory difficulty because the accumulation of acetylcholine at the cholinergic receptor site leads to reduced impulse transmission and muscle weakness. This is a crisis when the respiratory muscles are involved. Toxic effects of the drug would not include paralytic ileus, abdominal distention, or hypertension.

A middle-aged client is being treated for myasthenia gravis with neostigmine. What change in the client's health status would warrant immediate medical follow-up?

sudden muscle weakness Explanation: Sudden muscle weakness may be a sign of cholinergic crisis, which requires that the health care provider be notified immediately. The other listed changes in health also warrant assessment but are less likely to be as time dependent.

A client has been newly diagnosed with myasthenia gravis. What education should the nurse provide the client and family?

the signs and symptoms of a medication overdose Explanation: The client who is being treated for myasthenia gravis and their significant other should both receive instruction in drug administration, warning signs of drug overdose, and signs and symptoms to report immediately to enhance client knowledge about drug therapy and to promote compliance. Clients with myasthenia gravis will experience muscle weakness and should not be pushed to do more than they can tolerate. Level of consciousness is not a central concern in clients with myasthenia gravis. The illness is treated with cholinergic agonists, not anticholinergic medications (cholinergic antagonists)

The nurse is educating a client who has just been prescribed bethanechol. The nurse has taught the client to take the medication on an empty stomach. What is the rationale for the nurse's instruction?

to decrease nausea and vomiting Explanation: Administer bethanechol and all oral forms of direct-acting cholinergic agonists on an empty stomach to decrease nausea and vomiting. This directive is not motivated by the need to hasten absorption, prevent breakdown, or prevent gastric irritation.

Cholinergic drugs are contraindicated in all situations except in clients with:

urinary retention or postoperative abdominal distention due to paralytic ileus. Explanation: Cholinergic drugs are contraindicated in urinary or GI tract obstruction because they increase the contractility of smooth muscle in the urinary and GI systems and may result in injury to structures proximal to the obstruction. Cholinergic drugs are contraindicated in individuals with asthma because they may cause bronchoconstriction and increased respiratory secretions. Individuals with peptic ulcer disease should not use cholinergic drugs because they increase gastric acid secretion. Cholinergic drugs have limited but varied uses. A direct-acting drug, bethanechol, is used to treat urinary retention due to urinary bladder atony and postoperative abdominal distention due to paralytic ileus.