Hyoscine belongs to the group of medications called antispasmodics. Hyoscine is used to relieve smooth muscle spasms (cramps) in the stomach and intestines and in the bladder and urethra. Hyoscine reduces spasms by relaxing smooth muscles within the stomach, intestines, bladder and urethra. The injection form is used to relieve these same types of muscles spasms that might occur during diagnostic procedures.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are using this medication, speak to your doctor. Do not stop using this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to use this medication if their doctor has not prescribed it.

The usual dose of hyoscine tablets is 1 or 2 10 mg tablets per day. If you need to take this medication regularly, the usual dose is 1 tablet 3 to 5 times a day. The maximum dose is 6 tablets per day.

For the injection, the usual dose is 10 mg to 20 mg given by intramuscular (into a muscle), intravenous (into a vein), or subcutaneous (under the skin) injection. The maximum daily dose is 100 mg.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are using the medication without consulting your doctor.

Swallow the tablets whole with a glass of water. Do not crush or chew the tablets.

It is important to use this medication exactly as prescribed by your doctor. If you miss a dose, skip the missed dose and continue with your regular dosing schedule. Do not use a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Each 1 mL contains 20 mg of hyoscine butylbromide. Nonmedicinal ingredients: sodium chloride, hydrochloric acid and/or sodium hydroxide to adjust pH, and water for injection.

Do not use this medication if you:

• are allergic to hyoscine or any ingredients of this medication
• are allergic to other atropinics (e.g., atropine, scopolamine)
• have myasthenia gravis
• have megacolon (enlarged colon)
• have glaucoma
• have obstructive prostatic hypertrophy (enlarged or blocked prostate)
• have paralytic or obstructive ileus (bowel obstruction)

In addition, do not use the injection form of this medication if you:

• are receiving this medication as an intramuscular injection and are taking a blood thinner medication (e.g., warfarin, heparin)
• have narrowing of the gastrointestinal tract
• have a fast heartbeat
• have angina
• have heart failure

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who uses this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people using this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• blurred vision that is temporary
• constipation
• decreased ability to sweat
• diarrhea
• dizziness
• dry mouth
• fast heartbeat
• flushing
• nausea

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• difficulty urinating
• dizziness or lightheadedness when getting up from a lying or sitting position
• shortness of breath
• skin rash and itching
• vision changes

Stop using the medication and seek immediate medical attention if any of the following occur:

• painful red eye with loss of vision
• symptoms of a severe allergic reaction (e.g., hives; difficulty breathing; swelling of the face, mouth, tongue, or throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are using this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Difficulty urinating: This medication may make it more difficult for you to urinate. If you have an enlarged prostate, urinary retention, or difficulty urinating, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Fructose intolerance: Fructose intolerance is a rare condition in which fructose (a type of sugar) is not broken down by the body. One sugar-coated tablet of 10 mg contains 41.2 mg of sucrose, which can result in 411.8 mg of sucrose per day if the maximum recommended daily dose of hyoscine is needed. You should not use this medication if you have fructose intolerance.

Glaucoma: This medication may cause the symptoms of glaucoma (increased pressure in the eye) to develop or become worse. If you have glaucoma, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Report any changes in vision to your doctor as soon as possible while you are taking this medication.

Heart problems: This medication can increase your heart rate. If you have tachycardia (a fast heart rate), heart disease, an abnormal heart rhythm, heart failure, or mitral stenosis (a heart valve problem), discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Stomach and intestinal problems: If you have reflux esophagitis, a medical condition that narrow or blocks the intestines (e.g., achalasia, pyloroduodenal stenosis), or ulcerative colitis, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Vision problems: This medication may affect your vision. Do not drive or operate machinery until any vision problems have resolved. If you receive this medication during a diagnostic procedure, you should arrange for someone to drive you home from the hospital or clinic after your procedure.

Get immediate medical attention if you experience a painful red eye with loss of vision.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while using this medication, contact your doctor immediately.

Breast-feeding: It is not known if hyoscine passes into breast milk. If you are breast-feeding and are using this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

Seniors: Seniors are more sensitive to the side effects of this medication, especially constipation, dry mouth, and difficulty urinating. If you experience any of these side effects and they continue or are severe, contact your doctor.

There may be an interaction between hyoscine and any of the following:

• acetylcholinesterase inhibitors (e.g., donepezil, galantamine, rivastigmine)
• aclidinium
• alcohol
• alpha agonists (e.g., clonidine, guanfacine)
• amantadine
• antihistamines (e.g., azelastine, cetirizine, doxylamine, diphenhydramine, hydroxyzine, loratadine, rupatadine)
• antipsychotics (e.g., cariprazine, chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
• atropine
• barbiturates (e.g., butalbital, phenobarbital)
• benzodiazepines (e.g., alprazolam, diazepam, lorazepam)
• benztropine
• botulinum toxin
• brimonidine
• buprenorphine
• butorphanol
• cannabis
• chloral hydrate
• clidinium
• darifenacin
• diphenoxylate
• disopyramide
• efavirenz
• entacapone
• esketamine
• ethopropazine
• fesoterodine
• flibanserin
• flunarizine
• galantamine
• general anesthetics (medications used to put people to sleep before surgery)
• glucagon
• glycopyrrolate
• ipratropium
• kava kava
• ketotifen
• lemborexant
• magnesium sulfate
• MAO inhibitors (e.g., moclobemide, phenelzine, tranylcypromine)
• methadone
• metoclopramide
• minocycline
• mirabegron
• mirtazapine
• muscle relaxants (e.g., baclofen, cyclobenzaprine, methocarbamol, orphenadrine)
• nabilone
• narcotic pain relievers (e.g., codeine, fentanyl, morphine, oxycodone, tapentadol, tramadol)
• nitroglycerin
• olopatadine
• oxybutynin
• perampanel
• pizotifen
• pomalidomide
• potassium chloride
• pramipexole
• pregabalin
• propiverine
• prucalopride
• ropinirole
• rotigotine
• seizure medications (e.g., clobazam, levetiracetam, primidone, rufinamide, topiramate, valproic acid, zonisamide)
• sodium oxybate
• solifenacin
• tetrabenazine
• thalidomide
• thiazide diuretics (water pills; e.g., hydrochlorothiazide, indapamide, metolazone)
• tiotropium
• tizanidine
• tolterodine
• trazodone
• tricyclic antidepressants (e.g., amitriptyline, desipramine, nortriptyline)
• trihexyphenidyl
• trospium
• umeclidinium
• valerian
• zolpidem
• zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.