Hyoscyamine

Administration

  • Type: Anticholinergic
  • Dosage Forms: TAB 0.125mg; SL TAB: 0.125mg; INJ: 0.5 mg/mL; Drops 0.125 mg/mL
  • Routes of Administration: Oral, sublingual, IM/IV
  • Common Trade Names: Levsin

Adult Dosing

GI Tract spasm

  • 0.125-0.25 mg PO/SL q4h prn
    • Max: 1.5 mg/day

Bladder spasm

  • 0.125-0.25 mg PO/SL q4h prn
    • Max: 1.5 mg/day

IBS, adjunct tx

  • 0.125-0.25 mg PO/SL q4h prn
    • Max: 1.5 mg/day

PUD, adjunct tx

  • 0.125-0.25 mg PO/SL q4h prn
    • Max: 1.5 mg/day

Parkinson's disease, adjunct tx

  • 0.125-0.25 mg PO/SL q4h prn
    • Max: 1.5 mg/day

Biliary colic, adjunct tx

  • 0.125-0.25 mg PO/SL q4h prn
    • Max: 1.5 mg/day

Renal colic, adjunct tx

  • 0.125-0.25 mg PO/SL q4h prn
    • Max: 1.5 mg/day

Rhinitis

  • 0.125-0.25 mg PO/SL q4h prn
    • Max: 1.5 mg/day

Diagnostic procedures

  • 0.25-0.5mg SC/IM/IV x1

Anesthesia adjunct

  • 5mcg/kg SC/IM/IV x1

Surgery adjunct

  • 0.125 mg IV prn

Cholinesterase overdose

  • Give 0.3-0.6 mg IV for each 0.5-2 mg neostigmine or physostigmine

Pediatric Dosing

Colic, infantile

  • <2 yo, 3.4-4.9 kg
    • 4 drops PO q4h prn
  • <2 yo, 5-6.9 kg
    • 5 drops PO q4h prn
  • <2 yo, 7-9.9 kg
    • 6 drops PO q4h prn
  • <2 yo, >10 kg
    • 8 drops PO q4h prn

Bladder or GI Tract spasm

  • 2-11 yo
    • 0.0625-0.125 mg PO/SL q4h prn
  • 12+ yo
    • 0.125-0.25 mg PO/SL q4h prn

Anesthesia adjunct

  • >2 yo
    • 5 mcg/kg SC/IM/IV x1

Special Populations

Renal Dosing

  • Adult: Caution advised
  • Pediatric: Caution advised

Hepatic Dosing

  • Adult: Caution advised
  • Pediatric: Caution advised

Contraindications

Adverse Reactions

Serious

Common

Pharmacology

  • Half-life: 2-3.5 hr (7.5 hr ER form)
  • Metabolism: Liver
  • Excretion: Urine primarily (30-50% unchanged)

Mechanism of Action

  • Antagonizes acetylcholine receptors

Comments

See Also

References

Authors:

Jonathan Warren