Antispasmodics

What are antispasmodics?

Antispasmodics are medications that help relax the smooth muscles that line the walls of your internal organs. Healthcare providers often prescribe antispasmodics to help relieve abdominal pain related to muscle cramps in your digestive system or urinary system, or to reduce excessive urges to pee or poop.

What are antispasmodics used for?

You might take antispasmodics to help treat spasms in your abdominal or urinary organs, including:

• Irritable bowel syndrome (IBS).
• Colon spasms.
• Functional dyspepsia.
• Menstrual cramps.
• Biliary colic.
• Gallbladder pain.
• Pancreatitis.
• Overactive bladder.

Healthcare providers also use antispasmodics in medical procedures. They might give you the medication as an injection before your procedure to help relax you and sedate your digestive system.

How do antispasmodics work?

Different types of antispasmodic medications work by different mechanisms. In the U.S., the most commonly used antispasmodics come from a class of drugs called antimuscarinics. These drugs act on your parasympathetic nervous system to block the signals that activate your smooth muscles. Other types of antispasmodics work directly on the smooth muscles in your gut (your stomach and intestines).

• Antimuscarinics: Also called anticholinergics, these antispasmodic drugs work by blocking certain nerve cells from receiving certain signals. Nerve cells (chemoreceptors) receive chemical messages (neurotransmitters) that tell your smooth muscles to contract. Antimuscarinic drugs block these messages, preventing the muscles from contracting.
• Calcium channel blockers: While they aren’t technically classified as antispasmodics, calcium channel blockers relax your smooth muscles by inhibiting calcium uptake. Smooth muscles need calcium to contract, so limiting calcium access reduces contractions. These drugs can affect the smooth muscles in your blood vessels as well as in your gut. U.S. healthcare providers don’t prescribe them for gut-related conditions, but providers in other countries sometimes do.
• Direct smooth muscle relaxants: These are medications that target the muscles in your gut specifically. They work by inhibiting calcium and sodium uptake in these muscles, which the muscles need to contract. Direct smooth muscle relaxants include some prescription drugs available in other countries, but not in the U.S. They also include certain essential oils, like peppermint oil, which work the same way.

What are some commonly prescribed antispasmodic drugs?

Antispasmodic drugs available in the U.S include:

• Dicyclomine.
• Hyoscyamine.
• Atropine.
• Scopolamine.
• Tolterodine.
• Flavoxate.
• Oxybutynin.
• Mirabegron.

Which antispasmodics can I get OTC?

In the U.S., peppermint oil capsules are the only antispasmodic medication you can get over the counter (OTC). These work directly on your gastrointestinal muscles. Chamomile tea is another option with milder effects, which may help calm intestinal or menstrual cramps. Canada, Mexico and the U.K. offer some OTC antispasmodic drugs, including the direct smooth muscle relaxants, alverine and mebeverine.

What are the potential side effects of different antispasmodics?

Antimuscarinics block signals in your parasympathetic nervous system, which can have side effects. Most are mild, but they can be more severe if you take too much or if you have certain preexisting conditions. For example, since these medications slow down the muscle movements in your GI tract, you should let your provider know if you’re prone to constipation. Other possible side effects include:

• Dry mouth.
• Dry eyes.
• Dizziness.
• Headaches.
• Blurred vision.
• Urinary retention.
• Fast heart rate.

Calcium channel blockers relax your blood vessels, which helps with high blood pressure but might be dangerous if you have low blood pressure. This is why they’re usually only prescribed for cardiovascular conditions in the U.S. Other possible side effects include dizziness, flushing, fatigue and swelling.

Peppermint oil rarely causes side effects, but it has been known to cause heartburn and nausea.

What’s the difference between antispasmodics vs. antispastics?

Antispasmodics and antispastics are two different types of muscle relaxers. Antispastics act on your skeletal muscles, which are the muscles that help you move your body. Antispasmodics act on the smooth muscles inside your organs that move automatically. These muscles are governed by your parasympathetic nervous system, a network of nerves that controls your automatic body functions.

A note from Cleveland Clinic

If you have frequent abdominal pain or other symptoms related to the muscle contractions inside your abdominal organs, antispasmodics may help. For occasional digestive system relief from symptoms such as stomach cramping or bloating, OTC peppermint oil capsules might be enough. But if your everyday bodily functions, like peeing or pooping, are painful, seek help from a qualified healthcare provider.