Hyoscine butylbromide (Buscopan): cramps and spasm relief

Buscopan is the best-known brand of hyoscine butylbromide. It is a muscle relaxant of the antispasmodic type, which makes it suited to pain that comes in waves because of muscle contraction. The NHS lists painful stomach cramps linked to irritable bowel syndrome, bladder cramps and period pain.

People sometimes confuse it with hyoscine hydrobromide. That is a different salt of hyoscine used to prevent travel sickness, and the two are not interchangeable.

Buscopan eases symptoms but does not treat their cause, so it is no substitute for finding out why cramps keep returning.

By relaxing smooth muscle in the digestive system and bladder, it reduces the contractions that make cramps hurt. The NHS says painful cramps should ease within 15 minutes of a dose.

Because relief depends on the muscle relaxing rather than on any change in the gut itself, effects wear off and the tablets are generally taken when pain occurs rather than on a fixed daily schedule.

Each Buscopan tablet contains 10 mg. For adults and children aged 12 and over the NHS gives 1 tablet three times a day, which may be raised to 2 tablets four times a day if needed. For children aged 6 to 11 it is 1 tablet three times a day. It can be taken with or without food, at the time cramps or period pain start.

Age limits depend on the product: Buscopan Cramps tablets are not for children under 5, and Buscopan IBS Relief is not for children under 11 and needs a doctor to have confirmed IBS first.

• Do not take it for more than 2 weeks unless your doctor tells you to; see a doctor if things worsen or do not improve in that time.

• Missed a dose? Take it when you remember unless the next one is close, and never double up.

• One extra tablet is unlikely to harm, but contact NHS 111 if you have taken 2 or more extra, or go to A&E if you feel seriously unwell.

Most adults can take Buscopan. The NHS asks you to talk to a doctor or pharmacist first if you have had an allergic reaction to it, or if you have acute angle closure glaucoma, a severely enlarged bowel, myasthenia gravis, a bowel blockage or paralytic ileus, heart problems or a very fast heart rate, or an overactive thyroid. Heartburn, severe constipation and ulcerative colitis are also on the list, as is an enlarged prostate or difficulty passing urine.

Certain symptoms mean the cramps should be investigated rather than treated at home. These include being 40 or over with new symptoms, recent blood in the stool, nausea or vomiting, loss of appetite or weight, unusual tiredness or paleness, abnormal vaginal bleeding or discharge, a high temperature and suspected food poisoning, particularly after travel.

Dry mouth, constipation and blurred vision are the more common effects. Sugar-free gum or sweets and cold drinks help a dry mouth, extra fibre and water help constipation, and blurred vision means not driving or using machinery until it clears; skip the next dose and speak to a healthcare professional if it persists.

Call NHS 111 for a fast heart rate or palpitations, difficulty passing urine, or a painful red eye with loss of vision, in which case stop the medicine straight away. Call 999 for swelling of the lips, mouth, throat or tongue, fast or struggling breathing, a tight throat, or collapse; do not drive yourself to A&E.

Report suspected reactions through the Yellow Card scheme.

Buscopan is not thought to be harmful in pregnancy but is not often recommended because there is limited safety information, so ask a professional first. It can be used while breastfeeding, although other options may be preferred; the amount in milk is probably low, short or occasional use is better than regular use, and a baby should be watched for unusual sleepiness, poor feeding, slow weight gain, irritability or constipation. There is no evidence it affects fertility.

Domperidone and metoclopramide, which are used for sickness, can stop it working and vice versa. Taking other IBS remedies alongside it brings extra side effects without extra relief. Medicines that can add to its side effects include antihistamines, amitriptyline, the antipsychotics clozapine and chlorpromazine, amantadine, quinidine, disopyramide and the inhalers salbutamol, ipratropium and tiotropium.

Alcohol is permitted within the national guidance of no more than 14 units a week. Blurred vision or dizziness can make driving unsafe, and you are legally responsible for judging whether you are fit to drive.

Triggers such as caffeine, fizzy drinks and fried food commonly aggravate cramping, so identifying and cutting back on personal triggers can reduce how much you need the tablets. With medical approval and no side effects, some people use it for 3 months or more, but that is a decision for the doctor.