Antispasmodics (GU): Nursing pharmacology

Urinary antispasmodics are medications that can be used to reduce involuntary contractions or spasms of the detrusor muscle, which is a wall of smooth muscle that surrounds the bladder. These spasms cause a sudden and frequent urge to urinate, and could result from conditions like urge incontinence or overactive bladder, as well as from a urinary tract infection or injury.

The most commonly used urinary antispasmodics include antimuscarinic medications like tolterodine, flavoxate, and oxybutynin, as well as beta-3 adrenergic agonists like mirabegron, which can be administered orally or topically. The way these work is by inhibiting the effects of the parasympathetic nervous system on the detrusor muscle, causing it to relax.

Now, side effects commonly associated with urinary antispasmodics include headaches, dizziness, and drowsiness. In addition, clients may experience dry eyes and blurry vision, as well as dry mouth and dry skin. Some clients may also have tachycardia, nausea, vomiting, constipation, urinary retention, as well as anxiety and restlessness. Finally, the most severe side effects of urinary antispasmodics include hyperthermia, confusion, and delirium. 

As far as contraindications go, urinary antispasmodics should not be given to clients with intestinal or urinary obstruction, as well as those with hypertension or cardiovascular disease. Another contraindication is narrow angle glaucoma, since these medications can worsen the obstruction of aqueous humor drainage. Finally, urinary antispasmodics are contraindicated in clients with myasthenia gravis.

Okay, when caring for your client with an overactive bladder who is prescribed a urinary antispasmodic, first obtain a baseline assessment of your client’s urinary symptoms, such as frequency, urgency, nocturia, and the degree of incontinence they are experiencing. Then, assess your client’s vital signs. Finally, review their laboratory test results, specifically BUN, creatinine, kidney function tests, as well as urinalysis and urine culture.

Be sure your client understands why they have been prescribed this medication and how it will help them with their symptoms. Next, explain that an extended release tablet should be taken whole, never crushed or chewed, and that it can be taken with or without food. If your client is prescribed a transdermal patch, instruct them to apply it on dry, smooth, intact skin that is free of lotions, oils or powders; and recommend the abdomen, hip or buttocks as ideal spots for the patch; in addition, explain the importance of rotating the application site to a different spot each time.