Smooth muscle relaxant drugs: what to know

Smooth muscle is found in the walls of the digestive tract, urinary tract, and some blood vessels. Medicines described as smooth muscle relaxants may ease organ cramping by reducing involuntary contraction. They are different from medicines used for a back spasm or other skeletal-muscle problem, even though everyday conversation may call both types muscle relaxants.

The correct medicine depends on the symptom and its cause. Abdominal cramping, urinary symptoms, and pain can also result from conditions that need a different treatment, so a medicine should not be chosen from its name alone.

Use the prescribed dose and follow instructions about timing, food, and driving. Tell the prescriber about glaucoma, difficulty passing urine, bowel obstruction, pregnancy, breastfeeding, heart conditions, and other medicines. Some products can cause dry mouth, constipation, blurred vision, dizziness, or drowsiness. Do not share a prescription or add an over-the-counter product without checking a pharmacist.

Seek urgent care for severe or worsening abdominal pain, repeated vomiting, a swollen abdomen, inability to pass urine or stool, fainting, confusion, trouble breathing, or facial swelling. Contact a clinician if cramps keep returning, symptoms change after starting treatment, or side effects interfere with walking, work, or hydration.

Is this medicine intended for smooth or skeletal muscle? What symptom is it treating, and what diagnosis needs to be excluded? Which side effects require a call? Can I drive, exercise, or combine it with my current medicines?