Hyoscine | Antispasmodic drug
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.
- Postoperative nausea and vomiting and sea sickness, leading to its use by scuba divers
- Motion sickness (where it is often applied as a transdermal patch behind the ear)
- Gastrointestinal spasms
- Renal or biliary spasms
- Aid in gastrointestinal radiology and endoscopy
- Irritable bowel syndrome
- Clozapine-induced hypersalivation (drooling)
- Bowel colic
- Eye inflammation
It is sometimes used as a premedication, (especially to reduce respiratory tract secretions) in surgery, mostly commonly by injection.
Mechanism of action
Hyoscine works by relaxing the muscle that is found in the walls of the stomach, intestines, bowel, bile duct and genito-urinary tract. This type of muscle is called smooth muscle or involuntary muscle. It normally contracts and relaxes without our conscious control and we are not normally aware of it. However, if the muscles go into spasm, this can cause pain. Hyoscine stops the spasms in the smooth muscle, allowing it to relax. This reduces the painful spasms and cramps.
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)
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
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
- decreased ability to sweat
- dry mouth
- fast heartbeat
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
- 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)
Due to interactions with metabolism of other drugs, hyoscine can cause significant unwanted side effects when taken with other medications. Specific attention should be paid to other medications in the same pharmacologic class as hyoscine, also known as anticholinergics.
The following medications could potentially interact with the metabolism of hyoscine: analgesics/pain medications, ethanol, zolpidem, thiazide diuretics, buprenorphine, anticholinergic drugs such as tiotropium.