What is the typical starting dose of Hyoscyamine (anticholinergic medication)?

Typical Starting Dose of Hyoscyamine

The typical starting dose of hyoscyamine for adults and pediatric patients 12 years of age and older is 0.125-0.25 mg (1-2 mL oral solution) every four hours as needed, not exceeding 12 mL (1.5 mg) in 24 hours. 1

Dosage Forms and Administration

Adult Dosing

• Oral solution: 1-2 mL (0.125-0.25 mg) every four hours as needed 1
• Maximum daily dose: 12 mL (1.5 mg) in 24 hours 1
• For anticholinergic effects in palliative care (management of secretions/death rattle): 0.125 mg orally/sublingually every 4 hours as needed 2

Pediatric Dosing

• Ages 2 to under 12 years: 1/4 to 1 mL every four hours as needed, not exceeding 6 mL in 24 hours 1
• Under 2 years: Weight-based dosing starting at 4 drops (0.01 mg) for 3.4 kg infants 1

Clinical Applications

Gastrointestinal Indications

• Used as an anticholinergic agent for management of:
  • Intestinal hypermotility 3
  • Abdominal cramping 1
  • Bowel obstruction symptoms in palliative care 2

Palliative Care Applications

• Effective for managing excessive secretions in terminal care at doses of 0.125-0.25 mg 2
• Similar efficacy to other anticholinergics (atropine, scopolamine) for death rattle management 4
• Often used in combination with other medications for symptom management in end-of-life care 2

Important Considerations and Precautions

Side Effects to Monitor

• Central anticholinergic effects: confusion, agitation, delirium (particularly in elderly or debilitated patients) 5
• Cardiovascular effects: sinus tachycardia reported in up to 27% of patients in some studies 6
• May worsen gastroesophageal reflux by increasing the number of acid reflux episodes 7

Contraindications

• Use with caution in patients with:
  • Glaucoma 2
  • Prostatic hypertrophy 1
  • Cardiac conditions 6
  • Gastrointestinal reflux disease 7

Clinical Pearls

• Hyoscyamine is an anticholinergic medication that blocks muscarinic receptors, reducing smooth muscle spasms and secretions 2
• In palliative care, it's often used as part of a multimodal approach for symptom management 2
• For procedural use (such as endoscopy), the typical dose is 0.5 mg, though evidence for efficacy is mixed 3, 6
• When used for bowel obstruction management in palliative care, it's typically administered at 0.125 mg orally/sublingually every 4 hours as needed 2
• Careful monitoring is required, especially in elderly patients, due to potential for anticholinergic side effects 5