Pharmacology · chapter 35 · Urinary and Bladder Disorder Drugs
Urinary Antispasmodics, Antimuscarinics, and Anticholinergics
The 14 things this section of the textbook says that you are most likely to be asked about — quoted word for word, not retold. Then 6 practice questions with the reasoning.
Key points
What these drugs are used for
These drugs are commonly used to treat conditions characterized by frequent urination, urgency, and sometimes urinary incontinence.
Relaxing the detrusor muscle
They affect the urinary detrusor muscle, causing it to relax the bladder, allowing for increased bladder filling and thereby reducing urinary urgency and episodes of urinary incontinence.
Oxybutynin adverse effects
Adverse effects include insomnia, dizziness, headache, blurred vision, dry mouth, constipation, nausea, dyspepsia, angioedema, and urinary retention.
Main contraindications
Contraindications include urinary and gastric retention, uncontrolled narrow angle glaucoma, and hypersensitivity to the drug or any of its components.
Mirabegron is a beta-3 agonist
Mirabegron is a selective beta-3 adrenoceptor agonist that enhances bladder smooth muscle relaxation and is used to treat overactive bladder with symptoms of urge urinary incontinence, urgency, and urinary frequency (O’Kane et al., 2022). Adverse effects include hypertension, urinary retention, and angioedema.
How antimuscarinics calm the bladder
By blocking the effects of acetylcholine, antimuscarinics help reduce the overactivity of the bladder muscles, thereby reducing urgency and urinary frequency (Loloi et al., 2022).
Typical adverse effects of the group
Typical adverse effects of common urinary antispasmodic, antimuscarinic, and anticholinergic drugs include dry mouth, constipation, nausea, dyspepsia, dizziness, headache, urinary retention, and visual disturbances such as blurred vision and sensitivity to sunlight.
Watch for urinary retention
Monitor the client’s urine output for signs of urinary retention, such as the inability to empty the bladder, distended bladder, and anxiousness because this is a serious adverse effect, and the client may need an intervention such as a urinary straight catheter to empty the bladder.
Taking oxybutynin
The client taking a urinary antispasmodic, antimuscarinic, or anticholinergic should: Take oxybutynin chloride with water on an empty stomach for better absorption.
Managing dry mouth
Use sugarless candy, gum, or a saliva substitute for dry mouth, which is an adverse effect of these drugs.
Preventing constipation
Increase dietary intake of fiber and increase fluid intake, if not contraindicated, to help reduce the risk of constipation.
Risk of overheating
From the book’s list of what the client should not do:
Become overheated while taking oxybutynin or urinary antimuscarinics or anticholinergics because these drugs cause body temperature to increase and could lead to heat stroke.
No alcohol
From the book’s list of what the client should not do:
Take these drugs with alcohol because alcohol may cause increased depression of the central nervous system, resulting in drowsiness, dizziness, and possibly seizures.
Oxybutynin boxed warning: angioedema
Oxybutynin chloride and drugs containing oxybutynin chloride may cause angioedema (swelling similar to hives) of the face, lips, tongue, and/or larynx when taken orally. This condition may interfere with breathing and require hospitalization or emergency treatment.
Terms to know
- Urinary antispasmodics
- Antispasmodics Urinary antispasmodics are medications that alleviate spasms or involuntary contractions of the bladder muscles.
- Antimuscarinics
- Antimuscarinics and Anticholinergics Antimuscarinics are drugs within the anticholinergic class that block the action of acetylcholine, a neurotransmitter involved in muscle contractions, including those of the bladder.
Practice questions
Stuck on select-all-that-apply? How to take them one option at a time.
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Every question here, with the answer
A client with overactive bladder is prescribed oxybutynin. Which item in the client's history should the nurse report before the first dose?
- Urge incontinence
- Seasonal allergies
- Mild hypertension controlled with diet
- Uncontrolled narrow angle glaucoma
Answer: Uncontrolled narrow angle glaucoma
Contraindications include urinary and gastric retention, uncontrolled narrow angle glaucoma and hypersensitivity. Urge incontinence is what the drug treats, and the other conditions are not listed contraindications.
An older adult client taking tolterodine has not voided for 8 hours, feels restless, and has a firm, distended lower abdomen. What does the nurse suspect?
- Urinary retention, a serious adverse effect
- Constipation only
- An expected therapeutic response
- Dehydration from reduced urine output
Answer: Urinary retention, a serious adverse effect
Inability to empty the bladder, a distended bladder and anxiousness are signs of urinary retention, a serious adverse effect that may need a straight catheter. It is not the expected effect of the drug.
A nurse is teaching a client who is starting oxybutynin. Which instructions should the nurse include? Select all that apply.
- Take an extra dose if urgency returns.
- Increase fiber and fluids to prevent constipation.
- Use sugarless gum or candy for dry mouth.
- Avoid becoming overheated.
- Avoid alcohol.
Answer: Increase fiber and fluids to prevent constipation., Use sugarless gum or candy for dry mouth., Avoid becoming overheated., Avoid alcohol.
Teaching covers sugarless gum or candy for dry mouth, fiber and fluids for constipation, avoiding overheating because of heat stroke risk, and avoiding alcohol. Extra doses can cause urinary retention.
Soon after taking oral oxybutynin, a client reports swelling of the lips and tongue. What is the nurse's priority?
- Tell the client to take the next dose with food.
- Offer sugarless candy for dry mouth.
- Assess the airway and get emergency help.
- Apply sunscreen.
Answer: Assess the airway and get emergency help.
Oxybutynin can cause angioedema of the face, lips, tongue or larynx that may interfere with breathing and require emergency treatment. The other actions do not address a threatened airway.
Which adverse effects are typical of urinary antispasmodic and anticholinergic drugs? Select all that apply.
- Constipation
- Blurred vision
- Urinary retention
- Diarrhea
- Dry mouth
Answer: Constipation, Blurred vision, Urinary retention, Dry mouth
Typical adverse effects include dry mouth, constipation, nausea, dizziness, urinary retention and blurred vision. Diarrhea is not listed; constipation is the typical bowel effect.
A client taking mirabegron for overactive bladder comes to a follow-up visit. Which assessment is most important for this drug?
- Blood glucose
- Blood pressure
- Hearing
- Serum potassium
Answer: Blood pressure
Adverse effects of mirabegron include hypertension, urinary retention and angioedema, so blood pressure is checked. The other assessments are not linked to mirabegron in the section.
Where every quote comes from
Section 35.2 Urinary Antispasmodics, Antimuscarinics, and Anticholinergics of Pharmacology for Nurses by Tina Barbour-Taylor, Leah Mueller (Sabato), Donna Paris, Dorie Weaver, OpenStax, 2024. Read the whole section free at openstax.org.
The textbook is licensed under CC BY-NC-SA 4.0. This page quotes it word for word and adds the headings, the order and the practice questions; references to the book's figures and stray spaces left by its formatting are removed. The page is shared under the same licence. Nothing here is sold.