Scopolamine (Transderm Scop, Scopace)

PONV prophylaxis - Transdermal patch is effective for PONV and postoperative/postdischarge nausea; apply the evening before or 2-4 hours before surgery because of slow onset.

Central anticholinergic syndrome - Crosses the blood-brain barrier, causing sedation, confusion, and delirium; physostigmine can reverse central effects if needed.

Elderly caution - A high-risk anticholinergic for older adults (delirium, falls, urinary retention); use conservatively.

Antisialagogue - Dries secretions for airway procedures, with more sedation/amnesia than glycopyrrolate (which does not cross the blood-brain barrier).

Drug Interactions - Additive with other anticholinergics (atropine, antihistamines, tricyclics) and CNS depressants; may delay gastric emptying and absorption of other drugs.

Pediatric Implications - Weight-based (6 mcg/kg, max 0.3 mg); children are more prone to anticholinergic toxicity, so use cautiously. The patch is not recommended in young children.

Obstetric Implications - Category C; crosses the placenta. Historically used in obstetrics but can cause neonatal anticholinergic effects and maternal amnesia; use only if clearly needed. Limited data in lactation.

Absolute:

Narrow-angle glaucoma

Relative:

Bladder-neck obstruction / BPH

GI or urinary obstruction

Myasthenia gravis

Caution:

Elderly

Hepatic/renal impairment

Cardiac disease (tachycardia)

PONV: 6 mcg/kg IV, max 0.3 mg (pediatric). Adults most often use the transdermal 1.5 mg patch rather than IV.

6 mcg/kg IM, max 0.3 mg; adult antisialagogue/sedation 0.3-0.65 mg IM.

Competitive antagonist at central and peripheral muscarinic acetylcholine receptors; antiemetic action via central vestibular and vomiting-center M receptors.

Hepatic

Renal

Transdermal patch: apply behind the ear, wash hands after handling to avoid ocular contact (unilateral mydriasis). Remove before MRI (metal backing).