scopolamine (Transderm Scop, Hyoscine)

Introduction

Tradenames: Transderm Scop, Hyoscine.

Indications

• injection
• adjunct to general anesthesia
  • pre-anesthetic sedation in conjunction with analgesics
• salivation
  • inhibition of salivation & excessive respiratory secretion prior to surgery
  • sialorrhea
• prevention of cholinergic effects during surgery
  • cardiac arrhythmias
  • hypotension
  • bradycardia
• Transderm Scop:
  • prevention of motion sickness
• ophthalmic:
  • mydriasis & cycloplegia
  • acute inflammatory conditions of the iris & uveal tract
    • posterior synechiae
• irritable bowel syndrome

Contraindications

narrow-angle glaucoma

Dosage

• Transderm Scop:
  • one patch (1.5 mg) behind ear
  • lasts up to 3 days
  • box of 4
• 0.32-0.65 mg SC/IM/IV (after dilution) TID-QID
• ophthalmic:
  • mydriasis & cycloplegia: 1-2 drops of 0.25% solution 1 hour before procedure
  • iridocyclitis: 1-2 drops of 0.25% solution QD-TID Solution (ophthalmic): 0.25% (5 mL, 15 mL)

Injection: (as hydrobromide) 0.4 mg/mL (1 mL)

Pharmacokinetics

• injection
  • rapidly absorbed from GI tract, IM & SC injections
  • distribution is unknown; does cross the blood-brain barrier
  • metabolic & excetory fate is unknown, but thought to be completely metabolized by the liver & excreted in the urine
• ophthalmic
  • maximal mydriasis in 15-30 minutes; effects may last for several days
  • maximal cycloplegia in 30-45 minutes; effects may last up to 7 days

elimination via liver

Adverse effects

• common (> 10%)
  • constipation
  • decreased sweating*
  • dry nose, throat, or skin
  • irritation at site of injection
• less common (1-10%)
  • decreased flow of breast milk, difficulty swallowing, increased sensitivity to light
• uncommon (< 1%)
  • rash, confusion, increased intraocular pain, orthostatic hypotension, bloating, difficulty urinating, blurred vision, drowsiness, headache, loss of memory, nausea/vomiting, weakness, tiredness, ventricular fibrillation, tachycardia, palpitations, ataxia
• other
  • drowsiness
  • cycloplegia
  • hallucinations
• ophthalmic
  • common (> 10%)
    • blurred vision, photophobia
  • less common (1-10%)
    • local irritation, congestion, increased intraocular pressure
  • uncommon (< 1%)
    • vascular congestion, edema, drowsiness, exudate, eczematoid dermatitis, follicular conjunctivitis

* patch can increase body temperature & result in heat injury

• drug adverse effects of parasympatholytics

Drug interactions

• incompatible with alkali solutions

• drug interaction(s) of parasympatholytic with parasympathomimetic

Mechanism of action

• more potent anti-muscarinic activity than atropine on the iris, ciliary body, salivary glands, sweat glands
• less potent anti-muscarinic activity than atropine on the heart, bronchial smooth muscle & intestinal smooth muscle

More general terms

• belladonna alkaloid
• parasympatholytic (anticholinergic, antimuscarinic agent)
• anti-emetic
• mydriatic agent
• cycloplegic agent

Additional terms

• atropine/attapulgite/hyoscyamine/scopolamine (Donnagel)
• atropine/belladonna/hyoscyamine/phenobarbital/scopolamine (Donnatal)

Component of

• atropine/hyoscyamine/scopolamine
• atropine/hyoscyamine/phenobarbital/scopolamine
• atropine/chlorpheniramine/hyoscyamine/pseudoephedrine/scopolamine
• phenylephrine/scopolamine
• hyoscyamine/scopolamine
• hyoscyamine/phenylephrine/pseudoephedrine/scopolamine
• chlorpheniramine/phenylephrine/scopolamine
• chlorpheniramine/hyoscyamine/pseudoephedrine/scopolamine
• chlorpheniramine/hyoscyamine/phenylephrine/scopolamine
• chlorpheniramine/hyoscyamine/phenylephrine/phenylpropanolamine/scopolamine
• hyoscyamine/phenobarbital/scopolamine
• atropine/belladonna/hyoscyamine/phenobarbital/scopolamine (Donnatal)
• atropine/attapulgite/hyoscyamine/scopolamine (Donnagel)

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5184
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5809
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=517999
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=8240
• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=3000322