Adult: For acute spasms and prevention of spasms in diagnostic procedures: As hyoscine butylbromide: 20 mg via slow IV or IM inj, may repeat dose after 30 minutes if needed. Max: 100 mg daily. Dosage and treatment recommendations may vary among countries and individual products (refer to specific product guidelines).
Adult: For the prevention of excessive bronchial salivary secretions during general anaesthesia: As hyoscine hydrobromide: 200-600 mcg given via IM or SC inj prior to induction of anaesthesia. If needed for acute use, same doses may be administered via IV inj. Dosage and treatment recommendations may vary among countries and individual products (refer to specific product guidelines). Child: For the prevention of excessive bronchial salivary secretions during general anaesthesia: As hyoscine hydrobromide: 150 mcg/kg given via IM or SC inj 30-60 minutes prior to induction of anaesthesia. If needed for acute use, same doses may be administered via IV inj. Dosage and treatment recommendations may vary among countries and individual products (refer to specific product guidelines).
Adult: As adjunct to opioid analgesics: As hyoscine butylbromide: 20 mg via slow IV or IM inj, may repeat dose after 30 minutes if needed. Max: 100 mg daily. Dosage and treatment recommendations may vary among countries and individual products (refer to specific product guidelines).
Adult: As hyoscine butylbromide: 20 mg 4 times daily. Continuous intake on a daily basis or for extended periods is not recommended without determining the cause of abdominal pain. Dosing recommendations may vary among countries and individual products (refer to specific product guidelines). Child: As hyoscine butylbromide: 6-11 years 10 mg tid; ≥12 years Same as adult dose. Recommendations may vary among countries and individual products (refer to specific product guidelines).
Oral Prophylaxis of motion sickness
Adult: As hyoscine hydrobromide: Initially, 300 mcg taken 20-30 minutes before travel, then repeat 6 hourly if needed. Max: 900 mcg daily. Dosage recommendations may vary among countries and individual products (refer to specific product guidelines). Child: As hyoscine hydrobromide: 3-4 years Initially, 75 mcg; may repeat the dose once, if needed. Max: 150 mcg daily; >4-10 years 75-150 mcg, repeat 6 hourly if needed. Max: 450 mcg daily; >10 years 150-300 mcg, then repeat 6 hourly if needed. Max: 900 mcg daily. All doses should be taken 20-30 minutes before a journey. Dosage and age recommendations may vary among countries and individual products (refer to specific product guidelines).
Oral Irritable bowel syndrome
Adult: For the symptomatic relief of irritable bowel syndrome: As hyoscine butylbromide: Initially, 10 mg tid; may increase dose up to 20 mg 4 times daily, if needed. Continuous intake on a daily basis or for extended periods is not recommended without determining the cause of abdominal pain. Child: ≥12 years As hyoscine butylbromide: Same as adult dose.
Transdermal Postoperative nausea and vomiting
Adult: For the prevention of nausea and vomiting associated with recovery from surgery (excluding caesarean section) and anaesthesia or opioid analgesia: As hyoscine base: Apply 1 patch (1 mg/3 days patch) behind the ear in the evening before the surgery. Remove the patch 24 hours after the surgery. Treatment recommendations may vary among countries and individual products (refer to specific product guidelines). Child: There is limited information regarding the use of this drug in this population, treatment recommendations may vary among countries and individual products (refer to specific product guidelines).
Transdermal Prophylaxis of motion sickness
Adult: As hyoscine hydrobromide: Apply 1 patch (1.5 mg/patch) behind the ear, 5-6 hours before travelling or in the evening prior to travel, then remove at the end of the journey. As hyoscine base: Apply 1 patch (1 mg/3 days patch) behind the ear, at least 4 hours before the required antiemetic effect for use up to 72 hours. If prolonged protection is needed, remove the 1st patch after 72 hours and apply a new patch behind the other ear. Child: ≥10 years As hyoscine hydrobromide: Same as adult dose.
What are the brands available for Hyoscine in Hong Kong?
Hyoscine butylbromide May be taken with or without food. Hyoscine hydrobromide May be taken with or without food.
Reconstitution
IV inj: As hyoscine butylbromide: May be diluted with an appropriate amount of NaCl 0.9% or dextrose 5% solution. As hyoscine hydrobromide: Dilute with an equal amount of sterile water for inj. Recommendations for dilution may vary among countries and individual products (refer to specific product guidelines).
Contraindications
Angle-closure glaucoma. Oral/parenteral: Myasthenia gravis, prostatic hypertrophy with urinary retention, gastrointestinal obstruction, megacolon, pyloric stenosis or mechanical stenosis in the region of the gastrointestinal tract, paralytic or obstructive ileus. IV: Tachycardia. IM: Patients receiving anticoagulant therapy. Contraindications may vary between individual products (refer to specific product labelling for detailed information).
Special Precautions
Patient with history of psychosis and seizure disorder. Oral/parenteral: Patient with CV disease (e.g. acute MI, CAD, hypertension, cardiac arrhythmia) and conditions associated with tachycardia (e.g. cardiac failure or insufficiency, undergoing cardiac surgery, thyrotoxicosis); Down syndrome; predisposition to narrow-angle glaucoma, intestinal or urinary outlet obstruction; suspected or history of increased intraocular pressure (e.g. blurred vision, glaucomatous halo, pressure pain), open-angle glaucoma; hiatal hernia with reflux oesophagitis, impaired metabolic function, ulcerative colitis, diarrhoea, and pyrexia. Patients in cardiac surgery. Transdermal: Suspected or history of increased intraocular pressure (e.g. blurred vision, glaucomatous halo, pressure pain); prostatic hypertrophy with urinary retention; gastrointestinal obstruction, pyloric stenosis. Avoid use in pregnant women with severe pre-eclampsia. Patients undergoing MRI should remove the patch prior to procedure. Hyoscine butylbromide and hyoscine hydrobromide formulations are not equivalent and should not be interchanged on a mg/mg basis. Renal and hepatic impairment. Children and elderly. Pregnancy and lactation.
Adverse Reactions
Significant: Anticholinergic effects (e.g. xerostomia, blurred vision, mydriasis, urinary retention, decreased gastrointestinal motility); CNS effects (e.g. drowsiness, fatigue); psychiatric effects including agitation, confusion, excitement, disorientation, acute psychosis (e.g. delirium, hallucinations), amnesia/memory impairment, speech disturbance; increased frequency of seizures; transient bradycardia followed by tachycardia, palpitations, arrhythmias; increased intraocular pressure; hyperthermia; may aggravate or precipitate toxic megacolon; withdrawal symptoms (following discontinuation). Ear and labyrinth disorders: Vertigo. Eye disorders: Accommodation disorders, photophobia; eyelid irritation (transdermal). Gastrointestinal disorders: Nausea, vomiting, thirst, constipation, swallowing difficulties. General disorders and administration site conditions: Fatigue, inj site pain, transdermal application site reactions (e.g. rash, pruritus, burning sensation, irritation). Nervous system disorders: Headache, dizziness, drowsiness, restlessness. Renal and urinary disorders: Impaired micturition. Respiratory, thoracic and mediastinal disorders: Dyspnoea, pharyngitis. Skin and subcutaneous tissue disorders: Rash, erythema, urticaria, pruritus, dyshidrosis, dry skin. Vascular disorders: Hypotension, flushing. Potentially Fatal: Anaphylactic shock and anaphylactoid reactions.
This drug may occasionally cause dizziness, drowsiness or visual impairment, if affected, do not drive or operate machinery.
Monitoring Parameters
Monitor heart rate, body temperature, urinary output, and intraocular pressure. Assess for signs and symptoms of anaphylaxis, acute angle-closure glaucoma (e.g. blurred vision, eye pain or discomfort, red eye, loss of vision, visual halos or coloured images); cognitive impairment, new or worsening psychiatric symptoms; and persistent or worsening abdominal pain that may or may not occur with other symptoms (e.g. fever, nausea, vomiting, irregular bowel movements, abdominal tenderness, bloody stool, fainting, hypotension).
Overdosage
Symptoms: Transient visual disturbances, dilated pupils, dry mouth, thirst, nausea, vomiting, dry flushed skin, skin reddening, gastrointestinal motility inhibition, decreased bowel sounds, urinary retention, tachycardia, hypertension, supraventricular arrhythmias, Cheynes-Stokes respiration, hyperthermia, hyperpyrexia, agitation, CNS stimulation manifested as ataxia, confusion, incoordination, restlessness, hallucinations, and occasional seizures. In cases of severe overdose, initial CNS stimulation may progress to CNS depression, coma, and circulatory or respiratory failure. Management: Symptomatic and supportive treatment. Ensure adequate airway and establish cardiac and respiratory support. Check for possible multiple transdermal system applications, then immediately remove all transdermal patches. In case of oral ingestion, empty the stomach by inducing emesis or performing gastric lavage with medicinal charcoal which must be followed by magnesium sulfate (15%). For reversal of anticholinergic symptoms, may consider administration of parasympathomimetics such as physostigmine via slow IV inj. Cautiously administer diazepam to control excitation and convulsions. Administer local pilocarpine for individuals with glaucoma. Catheterisation may be needed for urinary retention. Cold baths can be done if hyperthermia occurs. Treatment of CV complications must be based on usual therapeutic principles. Intubation and artificial respiration may be considered in case of respiratory paralysis. Continuously monitor vital signs.
Drug Interactions
Increased risk for CNS adverse reactions with other CNS depressants (e.g. sedatives, hypnotics, opiates, anxiolytics) and other drugs that have anticholinergic properties (e.g. other belladonna alkaloids, meclozine, TCAs, muscle relaxants, sedating antihistamines). Enhanced anticholinergic effects with other drugs that have anticholinergic properties (e.g. amantadine, quinidine, disopyramide, antipsychotics, TCAs, antihistamines, tiotropium bromide, ipratropium bromide, atropine-like compounds). Concomitant use with dopamine antagonists (e.g. metoclopramide, domperidone) may reduce the effects of hyoscine and dopamine antagonists on the gastrointestinal tract. May enhance the tachycardic effects with β-adrenergic drugs. Decreased efficacy of sublingual nitrates caused by dry mouth.
Food Interaction
Enhanced CNS depressant or sedative effect with alcohol.
Lab Interference
May interfere with gastric secretion test; discontinue the use of hyoscine patch 10 days before testing.
Action
Description: Mechanism of Action: Hyoscine, a belladonna alkaloid, is an anticholinergic agent with central and peripheral actions. It competitively inhibits the action of acetylcholine at the post-ganglionic parasympathetic neuroeffector sites in the smooth muscles, secretory glands, and CNS. Additionally, it is thought to prevent motion-induced nausea and vomiting by blocking the transmission of cholinergic impulses from the vestibular nuclei to higher centres in the CNS, as well as from the reticular formation to the vomiting centre. Synonym(s): Scopolamine. Onset: As hyoscine base: Within 4 hours (transdermal). As hyoscine butylbromide: ≤15 mins (inj). As hyoscine hydrobromide: Approx 15 minutes (inj). Duration: As hyoscine base: 72 hours (transdermal). As hyoscine hydrobromide: Approx 4 hours (inj). Pharmacokinetics: Absorption: Readily absorbed from the gastrointestinal tract (as hyoscine hydrobromide [oral]); poorly absorbed from the gastrointestinal tract (as hyoscine butylbromide [oral]); rapidly absorbed (as hyoscine hydrobromide [IV, IM]); well absorbed after skin application (transdermal). Bioavailability: 8% (as hyoscine butylbromide [oral]). Time to peak plasma concentration: As hyoscine base: Within 24 hours (transdermal). As hyoscine butylbromide: Approx 2 hours (oral). As hyoscine hydrobromide: Approx 5 minutes (IV); approx 20 minutes (IM); approx 15 minutes (SC). Distribution: As hyoscine base and hyoscine hydrobromide: Crosses the blood-brain barrier and the placenta; enters breast milk. Mainly distributed in the muscle cells of the pelvic area, abdomen, and intramural ganglia of abdominal organs (as hyoscine butylbromide). Plasma protein binding: Approx 4.4%, mainly to albumin (as hyoscine butylbromide). Metabolism: Metabolised in the liver mainly via conjugation. Excretion: As hyoscine base: Transdermal: Via urine (<10% as unchanged drug and metabolites). As hyoscine butylbromide: Via urine (42-61%, half as unchanged drug [IV]; <0.1% [oral]); faeces (28-37% [IV]; 90% [oral]). As hyoscine hydrobromide: Via urine (variable, as unchanged drug and some metabolites [inj]; small amount as unchanged drug [oral]). Elimination half-life: As hyoscine base: 9.5 hours (transdermal). As hyoscine butylbromide: Approx 5 hours (IV); approx 6-11 hours (oral). As hyoscine hydrobromide: Approx 1-3.5 hours (inj).
Chemical Structure
Hyoscine Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 3000322, Hyoscine. https://pubchem.ncbi.nlm.nih.gov/compound/Hyoscine. Accessed Jan. 28, 2025.
Storage
Oral/Transdermal: Store below 25°C. Protect from light. Inj: Store below 30°C. Protect from light. Storage recommendations may vary among countries and individual products (refer to specific product guidelines).
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