Dicyclomine

Key facts

• Dicyclomine (also called dicycloverine) is an antispasmodic that relaxes smooth muscle in the gut wall to ease cramping and spasm.
• It is used in adults for the cramping pain of irritable bowel syndrome and other functional bowel disorders, usually taken before meals and at bedtime.
• Dicyclomine must never be given to infants. It has been linked to serious breathing difficulty, seizures, coma and death in babies under six months, and is contraindicated in this age group.
• Seek urgent care for severe abdominal pain that is new or different from your usual symptoms, or for difficulty passing urine, severe constipation, or eye pain.

What dicyclomine treats

Dicyclomine treats the cramping abdominal pain and spasm of irritable bowel syndrome and other functional gastrointestinal disorders. It does not treat the underlying bowel disease or diarrhoea and constipation directly, and it is not given to babies for colic or any other reason.

How dicyclomine works

Gut muscle contracts under signals carried by the nerve chemical acetylcholine. Dicyclomine blocks the receptors acetylcholine acts on in the smooth muscle of the bowel wall, so the muscle relaxes and spasm eases. The same receptors exist elsewhere in the body, which is why dicyclomine also reduces saliva, sweat, and other gland secretions and can affect the eyes, bladder and heart rate.

Before you take it

• Do not use dicyclomine if you are breastfeeding. It passes into breast milk and carries the same risk of serious breathing problems seen in infants given the drug directly.
• Tell your prescriber if you have glaucoma, myasthenia gravis, a bowel obstruction, severe ulcerative colitis, an enlarged prostate with urinary difficulty, or unstable heart disease, since dicyclomine can worsen all of these.
• Tell your prescriber about other anticholinergic medicines you take, since effects can add up.
• Take care in hot weather or with strenuous exercise; dicyclomine reduces sweating, which can raise your risk of overheating.

Side effects

Common effects: dry mouth, blurred vision, drowsiness, dizziness, and constipation.

Seek urgent medical care for:

• Difficulty passing urine, or a swollen, painful bladder.
• Severe constipation or abdominal bloating that does not settle.
• Sudden eye pain, blurred vision, or halos around lights, which can mean raised eye pressure.
• A fast or irregular heartbeat, confusion, or hallucinations.

Safety essentials

• Never give dicyclomine to an infant. It has caused fatal breathing problems, seizures and coma in babies under six months and must not be used, or passed on through breast milk, in this age group.
• Avoid it, or use it only under close medical supervision, if you have glaucoma, myasthenia gravis, a bowel obstruction, or urinary retention, since blocking acetylcholine can worsen all of these.
• It can reduce sweating and increase the risk of overheating in hot weather or during exercise; stay cool and hydrated.
• Drowsiness and blurred vision can affect driving or operating machinery; be cautious until you know how it affects you.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.