Hyoscyamine
Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.
Hyoscyamine (brand name Levsin) — Antispasmodic; Anticholinergic.
Identification
- Therapeutic class: Antispasmodic.
- Pharmacologic class: Anticholinergic.
Pharmacology
- Mechanism of action: Blocks acetylcholine to reduce GI motility and secretions.
- Onset / peak / duration: SL onset rapid; ER lasts about 12 hours.
- Half-life / therapeutic level: Half-life 2 to 4 hours; no routine level.
Clinical use
- Indications: GI spasm, irritable bowel syndrome, biliary or renal colic.
- Usual dose, route, frequency: 0.125 to 0.25 mg PO or SL up to four times daily.
- Maximum dose / adjustments: Max 1.5 mg/day; caution in elderly.
Safety
- Contraindications: Glaucoma, obstructive GI or urinary disease, myasthenia gravis.
- Black box warning: None.
- Interactions: Other anticholinergics, antihistamines.
- Pregnancy / lactation: Use with caution.
- High-alert: No.
Adverse effects
- Common side effects: Dry mouth, blurred vision, constipation, dizziness.
- Serious effects to report: Confusion, urinary retention, rapid heartbeat.
- Antidote / reversal: Supportive care.
Nursing process
- Assessment before administration: Glaucoma, urinary and GI status.
- Interventions during therapy: Monitor anticholinergic effects.
- Monitor: Bowel and bladder function.
- Evaluation / expected outcome: Reduced spasm.
Patient teaching
- Patient teaching: Expect dry mouth; avoid overheating.
- Notify provider if: Trouble urinating, confusion.
- Administration tips: SL dissolves under the tongue.