Hyoscyamine


Generic Medicine Info
Indications and Dosage
Intravenous
Aid in diagnostic procedures
Adult: Usual dose: 0.25-0.5 mg 5-10 minutes prior to the procedure.

Intravenous
Prophylaxis of cholinesterase inhibitor induced muscarinic adverse effects
Adult: Usual dose: 0.2 mg for each 1 mg of neostigmine or the equivalent dose of physostigmine or pyridostigmine given. Administer concomitantly with (in a separate syringe) or a few minutes before the anticholinesterase agent; if experiencing bradycardia, administer before the anticholinesterase agent.
Child: >2 years Same as adult dose.

Intravenous
Reversal of bradycardia
Adult: For the reversal of drug induced bradycardia during surgery: 0.125 mg, repeated as necessary.
Child: >2 years Same as adult dose.

Oral
Poisoning, anticholinesterase
Adult: Maintenance therapy following parenteral administration: 0.5-1 mg at intervals of several hours until signs and symptoms completely subside. Refer to specific product guideline or local treatment protocols for more detailed dosing information.

Oral
Biliary colic, Renal colic
Adult: For the symptomatic relief of cases, in combination with morphine or other narcotics: Conventional tab, orally disintegrating tab, oral solution, elixir: 0.125-0.25 mg 4 hourly or as needed. Max: 1.5 mg daily. Alternatively, as extended release tab: 0.375-0.75 mg 12 hourly. Max: 1.5 mg daily. Dosage may be adjusted based on patient condition and severity of symptoms. Dosage recommendation may vary among countries or individual products. Refer to specific product guidelines.
Child: <2 years Oral drops: Dosage requirements may vary according to patient weight, refer to specific product guideline for dosing information. 2-11 years Conventional tab: 0.0625-0.125 mg 4 hourly or as needed. Max: 0.75 mg daily. Oral solution: 0.03125-0.125 mg 4 hourly or as needed. Max: 0.75 mg daily. Elixir: Dosage requirements may vary according to patient weight, refer to specific product guideline for dosing information. ≥12 years Conventional tab, extended release tab, orally disintegrating tab, oral solution, elixir: Same as adult dose.

Oral
Gastrointestinal disorders
Adult: For the management of cases such as gastric secretion, visceral spasm and hypermotility in spastic colitis, spastic bladder, cystitis, pylorospasm, and associated abdominal cramps: Conventional tab, orally disintegrating tab, oral solution, elixir: 0.125-0.25 mg 4 hourly or as needed. Max: 1.5 mg daily. Alternatively, as extended release tab: 0.375-0.75 mg 12 hourly. Max: 1.5 mg daily. Dosage may be adjusted based on patient condition and severity of symptoms. Dosage recommendations may vary among individual products. Refer to specific product guidelines.
Child: <2 years Oral drops: Dosage requirements may vary according to patient weight, refer to specific product guideline for dosing information. 2-11 years Conventional tab: 0.0625-0.125 mg 4 hourly or as needed. Max: 0.75 mg daily. Oral solution: 0.03125-0.125 mg 4 hourly or as needed. Max: 0.75 mg daily. Elixir: Dosage requirements may vary according to patient weight, refer to specific product guideline for dosing information. ≥12 years Conventional tab, orally disintegrating tab, extended release tab, oral solution, elixir: Same as adult dose.

Oral
Irritable bowel syndrome, Peptic ulcer
Adult: As adjunctive therapy: Orally disintegrating tab: 0.125-0.25 mg 4 hourly or as needed. Max: 1.5 mg daily. Dosage may be adjusted based on patient condition and severity of symptoms.
Child: ≥12 years Same as adult dose.

Oral
Irritable bowel syndrome, Neurogenic bladder disorders, Neurogenic bowel, Parkinsonism, Peptic ulcer
Adult: As adjunctive therapy: Conventional tab, oral solution, elixir: 0.125-0.25 mg 4 hourly or as needed. Max: 1.5 mg daily. Alternatively, as extended release tab: 0.375-0.75 mg 12 hourly. Max: 1.5 mg daily. Dosage may be adjusted based on patient condition and severity of symptoms. Dosage recommendations may vary among individual products. Refer to specific product guidelines.
Child: <2 years Oral drops: Dosage requirements may vary according to patient weight, refer to specific product guideline for dosing information. 2-11 years Conventional tab: 0.0625-0.125 mg 4 hourly or as needed. Max: 0.75 mg daily. Oral solution: 0.03125-0.125 mg 4 hourly or as needed. Max: 0.75 mg daily. Elixir: Dosage requirements may vary according to patient weight, refer to specific product guideline for dosing information. ≥12 years Conventional tab, orally disintegrating tab, extended release tab, oral solution, elixir: Same as adult dose.

Parenteral
Preoperative medication
Adult: Recommended dose: 0.005 mg/kg given via IV, IM, or SC inj 30-60 minutes prior to the anticipated time of induction of anaesthesia or at the time other pre-anaesthetic narcotics or sedatives are given.
Child: >2 years Same as adult dose.

Parenteral
Poisoning, anticholinesterase
Adult: Usual dose: 1-2 mg, preferably given via IV inj. Additional doses of 1 mg every 3-10 minutes may be given via IM or IV inj until muscarinic signs and symptoms subside and may be repeated if reappearance occurred. Doses up to 25 mg may be required during the 1st 24 hours of therapy. Transfer to oral medications for maintenance therapy.

Parenteral
Irritable bowel syndrome, Neurogenic bowel, Peptic ulcer
Adult: Usual dose: 0.25-0.5 mg given via IV, IM, or SC inj 2-4 times daily at 4-hour intervals. Dose is adjusted according to patient response and tolerance.

Sublingual
Irritable bowel syndrome, Neurogenic bladder disorders, Neurogenic bowel, Peptic ulcer
Adult: As adjunctive therapy: 0.125-0.25 mg 4 hourly or as needed. Max: 1.5 mg daily. Dosage may be adjusted based on patient condition and severity of symptoms.
Child: 2-<12 years 0.0625-0.125 mg 4 hourly or as needed. Max: 0.75 mg daily. ≥12 years Same as adult dose.
Contraindications
Obstructive uropathy (e.g. bladder neck obstruction due to prostatic hypertrophy), myasthenia gravis, glaucoma; obstructive gastrointestinal tract disease (e.g. achalasia, pyloroduodenal stenosis), paralytic ileus, severe ulcerative colitis, toxic megacolon complicating ulcerative colitis, intestinal atony (in elderly or debilitated patients); unstable CV status; myocardial ischaemia.
Special Precautions
Patients with coronary artery disease, tachyarrhythmias, heart failure, hypertension; hiatal hernia with reflux oesophagitis, hyperthyroidism, autonomic neuropathy. Febrile patients or those subjected to increased environmental temperature (e.g. hot weather, exercise). Renal impairment. Children (including those with spastic paralysis or brain damage) and elderly. Pregnancy and lactation.
Adverse Reactions
Significant: Diarrhoea (particularly in patients with ileostomy or colostomy), heat prostration (e.g. fever, heat stroke due to decreased sweating); psychosis (particularly in patients with increased sensitivity to anticholinergic effects); dental caries, periodontal disease, oral candidiasis, discomfort due to decreased salivation (prolonged use).
Cardiac disorders: Tachycardia, palpitations.
Eye disorders: Blurred vision, mydriasis, cycloplegia, increased intraocular pressure.
Gastrointestinal disorders: Abdominal pain, nausea, vomiting, constipation, ageusia, bloating, dysgeusia, dysphagia, heartburn, xerostomia.
General disorders and administration site conditions: Fatigue, weakness, fever.
Immune system disorders: Hypersensitivity reaction.
Nervous system disorders: Short-term memory loss; excitement (particularly in elderly); dizziness, drowsiness, headache, nervousness, speech disturbance, ataxia.
Psychiatric disorders: Hallucination, insomnia, confusion, disorientation, euphoria, anxiety, agitation and mannerisms.
Renal and urinary disorders: Urinary retention and hesitancy.
Reproductive system and breast disorders: Decreased lactation, impotence.
Skin and subcutaneous tissue disorders: Hypohidrosis, urticaria.
Vascular disorders: Flushing.
Patient Counseling Information
This drug may cause drowsiness, dizziness, or blurred vision, if affected, do not drive or operate machinery.
Monitoring Parameters
Assess for signs of tachycardia prior to treatment initiation. Observe for excessive dryness of the mouth, throat, nose, or eyes.
Overdosage
Symptoms: Headache, vomiting, nausea, dilated pupils, blurred vision, dizziness, dryness of the mouth, hot dry skin, difficulty swallowing, and CNS stimulation. Management: Symptomatic treatment. Perform gastric lavage immediately. Administer physostigmine 0.5-2 mg IV and may repeat as necessary up to a total of 5 mg. May use tepid water sponge bath and hypothermic blanket to treat fever. In case of excitement to a degree which demands attention, administer Na thiopental 2% solution via slow IV inj or chloral hydrate 2% solution (100-200 mL) via rectal infusion. Initiate and maintain artificial respiration, in case of curare-like effect progressing to respiratory muscles paralysis, until effective respiratory action returns.
Drug Interactions
May increase adverse effects resulting from cholinergic blockade with other antimuscarinics, haloperidol, MAOIs, phenothiazines, TCAs, certain antihistamines; amantadine. May decrease absorption with antacids.
Action
Description: Hyoscyamine is a tertiary amine antimuscarinic agent that blocks acetylcholine action at the parasympathetic sites in the smooth muscle, cardiac muscle, sinoatrial node, atrioventricular node, and exocrine glands. It also inhibits gastrointestinal propulsive motility, decreases gastric acid secretion, and controls excessive bronchial, pharyngeal, and tracheal secretions.
Onset: IV/IM/SC: 2-3 minutes. Oral: 20-30 minutes (conventional tab). Sublingual: 5-20 minutes.
Duration: 4-6 hours (conventional tab); 8-12 hours (extended release tab).
Pharmacokinetics:
Absorption: Well and completely absorbed from the gastrointestinal tract. Time to peak plasma concentrations: Approx 4 hours (extended release tab).
Distribution: Distributed throughout the body. Crosses the placenta and blood brain barrier; enters breastmilk (small amounts). Plasma protein binding: Approx 50%.
Metabolism: Metabolised in the liver, partly hydrolysed to tropic acid, tropine and hyoscyamine glucuronide.
Excretion: Via urine (as unchanged drug within the 1st 12 hours). Elimination half-life: 2-3.5 hours (conventional tab); 7-9 hours (extended release tab); 3.5 hours (IV/IM/SC).
Chemical Structure

Chemical Structure Image
Hyoscyamine

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 154417, Hyoscyamine. https://pubchem.ncbi.nlm.nih.gov/compound/Hyoscyamine. Accessed Aug. 25, 2021.

Storage
Store between 15-30°C.
MIMS Class
Antacids, Antireflux Agents & Antiulcerants / Antidotes & Detoxifying Agents / Antispasmodics / Muscle Relaxants
ATC Classification
A03BA03 - hyoscyamine ; Belongs to the class of belladonna alkaloids, tertiary amines. Used in the treatment of functional gastrointestinal disorders.
References
Anon. Hyoscyamine. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. https://www.ahfscdi.com. Accessed 27/08/2020.

Anon. Hyoscyamine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 27/08/2020.

Buckingham R (ed). Hyoscyamine. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 27/08/2020.

Hyoscyamine Sulfate Drops (Method Pharmaceuticals, LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 27/08/2020.

Hyoscyamine Sulfate Elixir (Method Pharmaceuticals, LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 18/05/2021.

Hyoscyamine Sulfate Extended-Release Tablet (County Line Pharmaceuticals, LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 27/08/2020.

Hyoscyamine Sulfate Injection, Solution (BPI Labs LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 27/08/2020.

Hyoscyamine Sulfate ODT (Acella Pharmaceuticals, LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 27/08/2020.

Hyoscyamine Sulfate SL Tablet (RedPharm Drug, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 27/08/2020.

Hyoscyamine Sulfate Tablet (Wallace Pharmaceuticals Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 27/08/2020.

Disclaimer: This information is independently developed by MIMS based on Hyoscyamine from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2021 MIMS. All rights reserved. Powered by MIMS.com
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