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Antimuscarinic Pregnancy: §4.6, verbatim: 'The safety of this medicine in pregnancy has not been established. It should only be used during pregnancy, particularly in the first trimester, if the expected benefit to the mother outweighs any potential risk to the developing foetus. Caution is required during lactation as small amounts of this medicine may pass into breast milk.'

Hyoscine hydrobromide

Brand names: Joy-Rides, Kwells, Scopoderm

Hyoscine hydrobromide (scopolamine) is an antimuscarinic agent used for motion sickness and, in palliative care, for the management of excessive respiratory secretions.

Adult dose

Dose: 300 micrograms (one Kwells 300 microgram tablet). §4.2, verbatim: 'Adults: 1 tablet every 6 hours if required.' The strength is pinned by the product name, 'Kwells 300 microgram tablets'.
Route: Oral. §4.2, verbatim: 'Tablets to be sucked, chewed or swallowed.'
Frequency: Every 6 hours if required. §4.2, verbatim: 'Tablets to be taken up to 30 minutes before the start of the journey to prevent travel sickness, or at the onset of nausea.'
Max: Maximum 3 tablets in 24 hours, i.e. 900 micrograms in 24 hours. §4.2, verbatim: 'Do not take more than 3 tablets in 24 hours.'
SCOPE — READ BEFORE PUBLISHING. This is an ORAL MOTION-SICKNESS product SPC and nothing else. It carries NO posology for any other formulation, route or indication of hyoscine hydrobromide. In particular the bundle contains NO transdermal patch regimen (Scopoderm) and NO subcutaneous or continuous subcutaneous infusion regimen for respiratory secretions or hypersalivation in palliative care. This record must not be read as the drug's dose in those settings. ELDERLY (§4.2, verbatim): 'There is no special dosage regimen for the elderly and as such caution should be exercised.' §4.4 CAUTIONS, verbatim: 'The elderly and patients under medical care (in particular those at risk of acute urinary retention, or with cardiovascular, metabolic, gastrointestinal, liver or renal disease, or suffering from CNS disorders such as seizures) should consult a doctor before taking this product. In patients with ulcerative colitis its use may lead to ileus or megacolon. Antimuscarinics should be used with caution in persons with Down's Syndrome. Caution is advisable in patients with diarrhoea. Hyperthermia can occur at high ambient temperatures due to decreased sweating, therefore, Kwells should be used with caution in patients with fever.' §4.5 INTERACTIONS, verbatim: 'The effects of hyoscine may be enhanced by other drugs with anticholinergic properties (including amantadine, some antihistamines, phenothiazine antipsychotics and tricyclic antidepressants), therefore, combining these drugs with hyoscine should be avoided. There may be an increased risk of side effects when given with MAOIs due to inhibition of drug-metabolising enzymes. The sedative effect of Kwells may be enhanced with alcohol or CNS depressants. The reduction in gastric motility caused by Kwells may also affect the absorption of other drugs. There is an antagonism of effect of domperidone and metoclopramide on gastro-intestinal activity. There could be a reduced effect of sublingual nitrate tablets due to the failure to dissolve properly under the tongue owing to dry mouth.'

Paediatric dose

Route: Oral. §4.2: 'Tablets to be sucked, chewed or swallowed.'
Frequency: Every 6 hours if required, taken up to 30 minutes before the start of the journey or at the onset of nausea.
Max: Maximum 3 tablets in 24 hours, i.e. 900 micrograms in 24 hours. §4.2, verbatim: 'Do not take more than 1 1/2-3 tablets in 24 hours' — the stated range corresponds to the half-to-one tablet per dose range, so the absolute ceiling is 3 tablets (900 micrograms) in 24 hours and a child taking half tablets should not exceed 1 1/2 tablets (450 micrograms) in 24 hours.
dosePerKg is left NULL deliberately: this SPC's paediatric rule is AGE-BANDED and expressed in tablet fractions, not in mg/kg, so no weight-based calculation can be driven from it. §4.2 Children, verbatim: 'Children over 10: 1/2-1 tablet every 6 hours if required. Do not take more than 1 1/2-3 tablets in 24 hours.' With the 300 microgram tablet strength pinned by the product name, that is 150-300 micrograms every 6 hours if required. NO dose is given for children aged 10 years and under anywhere in the fetched bundle, and no minimum age is stated beyond 'over 10'. concentration is NULL because this is a tablet — the SPC states no milligrams-per-millilitre figure and no oral liquid exists in this bundle. Verify all under-18 dosing against a children's formulary before prescribing.

Dose adjustments

Renal

No dose adjustment for renal impairment is stated anywhere in the fetched SPC. §4.4 goes only as far as: 'patients under medical care (in particular those at risk of acute urinary retention, or with cardiovascular, metabolic, gastrointestinal, liver or renal disease, or suffering from CNS disorders such as seizures) should consult a doctor before taking this product.'

Hepatic

No dose adjustment for hepatic impairment is stated anywhere in the fetched SPC. §4.4 goes only as far as the same sentence: patients with 'liver or renal disease... should consult a doctor before taking this product.'

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Prostatic enlargement
  • Paralytic ileus
  • Pyloric stenosis
  • Glaucoma
  • Myasthenia gravis
  • Known sensitivity to hyoscine hydrobromide or any other component of the product

Side effects

  • §4.8 framing, verbatim: 'The listed adverse drug reactions are based on spontaneous reports, thus an organization according to CIOMS II categories of frequency is not pertinent.'
  • Nervous system: 'drowsiness, dizziness, sedation and somnolence are commonly reported'
  • Nervous system, less frequent: 'Central nervous system stimulation including restlessness, hallucinations and confusion, have been less frequently reported following the administration of hyoscine'
  • Nervous system, rare: 'There have been rare reports of an increase in seizure frequency in epileptic patients'
  • Eye: blurred vision, mydriasis
  • Gastrointestinal: dry mouth
  • General: 'hyperthermia at high temperatures due to decreased sweating'
  • Immune system: 'allergic reaction and anaphylactic reaction. Hypersensitivity reactions with respective laboratory and clinical manifestations, including asthma syndrome, mild to moderate reactions affecting skin, respiratory tract, gastrointestinal tract, and cardiovascular system, and symptoms such as rash, urticaria, oedema, pruritus, cardio-respiratory distress, have been reported.'

Monitoring

  • No monitoring requirement, test or interval is stated anywhere in the fetched sections of this SPC (§4.2, §4.3, §4.4, §4.5, §4.6, §4.8). Do not infer one from this source.
  • The nearest §4.4 equivalents are advisory, verbatim: 'The elderly and patients under medical care (in particular those at risk of acute urinary retention, or with cardiovascular, metabolic, gastrointestinal, liver or renal disease, or suffering from CNS disorders such as seizures) should consult a doctor before taking this product.'
  • Temperature (§4.4, verbatim): 'Hyperthermia can occur at high ambient temperatures due to decreased sweating, therefore, Kwells should be used with caution in patients with fever.'
  • Sedation is commonly reported (§4.8), so fitness to drive or operate machinery should be considered after each dose — the fetched sections state the sedative effect and its enhancement by alcohol or CNS depressants (§4.5) but give no formal monitoring instruction.

Clinical monograph

How it works

It is a competitive antagonist at muscarinic acetylcholine receptors and, being centrally penetrant, also acts within the central nervous system to reduce the vestibular and emetic responses underlying motion sickness.

Prescribing in practice

  • Antimuscarinic effects can precipitate or worsen angle-closure glaucoma, urinary retention and confusion, so use with caution in the elderly and in those at risk.
  • It commonly causes drowsiness, dry mouth and blurred vision, and may impair the ability to drive or operate machinery.
  • Distinguish hyoscine hydrobromide from hyoscine butylbromide, which is a peripherally acting antispasmodic with different uses, to avoid prescribing confusion.

Monitoring

Routine laboratory monitoring is not required; monitor clinically for antimuscarinic adverse effects, particularly in older or susceptible patients.

Counselling the patient

  • This medicine can make you drowsy and cause dry mouth and blurred vision; do not drive or operate machinery if affected.
  • Avoid alcohol, which can increase drowsiness.

Evidence & guidelines

Hyoscine hydrobromide is an established treatment for motion sickness and for the symptomatic control of respiratory secretions in palliative care.

Reference: Palliative care formulary; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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