Hyoscine (Scopolamine) Dosing in Children
For children 2 to under 12 years of age, administer 0.5 to 1 tablet (equivalent to approximately 0.15-0.3 mg) every 4 hours as needed, not exceeding 6 tablets in 24 hours; for children 12 years and older, use 1 to 2 tablets every 4 hours as needed, not exceeding 12 tablets in 24 hours. 1
Age-Based Dosing Recommendations
The FDA-approved dosing for oral hyoscine follows a straightforward age-stratified approach 1:
Children 2 to Under 12 Years
- Dose: ½ to 1 tablet every 4 hours or as needed 1
- Maximum daily dose: 6 tablets in 24 hours 1
- Administration: May be taken sublingually, orally, or chewed 1
Adolescents 12 Years and Older (Adult Dosing)
- Dose: 1 to 2 tablets every 4 hours or as needed 1
- Maximum daily dose: 12 tablets in 24 hours 1
- Administration: May be taken sublingually, orally, or chewed 1
Important Clinical Considerations
Bioavailability and Route Selection
Oral hyoscine has limited bioavailability (only 2.6% excreted unchanged in urine), suggesting significant first-pass metabolism 2. The maximum drug concentration occurs approximately 0.5 hours after oral administration 2. This rapid absorption but limited bioavailability explains why frequent dosing intervals (every 4 hours) are necessary 1.
Alternative Anticholinergic in Pediatrics
For specific pediatric indications requiring anticholinergic effects (such as preventing increased salivation during ketamine sedation), glycopyrrolate may be considered as an alternative, as it is specifically mentioned in American Academy of Pediatrics guidelines for pediatric use 3. This may be preferable when parenteral administration is needed or when more predictable pharmacokinetics are desired.
Common Pitfalls to Avoid
Do not use in children under 2 years of age - the FDA labeling does not provide dosing for this age group, reflecting insufficient safety and efficacy data 1.
Avoid dose escalation beyond maximum limits - hyoscine has dose-dependent adverse effects including hallucinations, vertigo, dry mouth, and drowsiness 2. The short half-life in plasma necessitates frequent dosing rather than larger individual doses 2.
Monitor for anticholinergic toxicity - children may be particularly susceptible to central nervous system effects including confusion and agitation 2. The drug readily crosses the blood-brain barrier and produces central sedative and amnestic effects 2.
Pharmacokinetic Rationale for Pediatric Dosing
The dosing adjustment in children reflects important developmental pharmacology principles 4. Children 2 years and older are essentially mature in terms of drug elimination pathways and differ from adults primarily in size 4. The weight-based reduction in the pediatric dose (approximately half the adult dose for younger children) accounts for differences in body surface area and drug clearance 5.