Contents

Search

trihexyphenidyl (Artane, Trihexy)

Tradename: Artane. Indications: 1) adjunctive treatment of all forms of parkinsonism including antipsychotic-induced extrapyramidal reactions 2) anticholinergic agents are the drugs of choice in Parkinson's disease patients presenting primarily with tremor 3) NOT for tardive dyskinesia Contraindications: Caution: 1) use with caution in warm weather & during exercise 2) elderly patients with atherosclerosis may be more susceptible to adverse effects 3) cardiac arrhythmias 4) hypertension 5) benign prostatic hypertrophy Dosage: 1) start 1-2 mg/day divided TID 2) increase as needed by 2 mg increments every 3-5 days 3) maintenance dose: 6-10 mg QD divided TID 4) a 4th daily dose if needed should be at bedtime 5) max 15 mg/day Tabs: 2 & 5 mg. Elixir: 2 mg/5 mL. Pharmacokinetics: 1) rapidly absorbed from the GI system following oral administration 2) onset of action is with 1 hour 3) duration of action is 6-12 hours Adverse effects: 1) common (> 10%) - constipation - decreased sweating - dry mouth, nose, throat or skin 2) less common (1-10%) - decreased flow of breast milk, difficulty swallowing, photosensitivity 3) 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 4) other - confusion in older patients - urinary retention in men - closed-angle glaucoma - mydriasis - nervousness - paralytic ileus - visual hallucinations Drug interactions: 1) concurrent administration of other anticholinergic agents may increase risk of adverse effects 2) increased psychedelic experience: in combination with cannabinoids, barbiturates, opiates, alcohol Mechanism of action: 1) antimuscarinic activity 2) direct spasmolytic activity on smooth muscle 3) mechanism of antiparkinsonian effects is unknown, but may result from central cholinergic inhibition 4) little effect on hypokinesia or rigidity

Interactions

drug interactions drug adverse effects of parasympatholytics

General

parasympatholytic (anticholinergic, antimuscarinic agent) pharmacologic agents for treatment of Parkinson's disease

Properties

MISC-INFO: elimination route LIVER KIDNEY pregnancy-category C safety in lactation ?

References

  1. The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996.
  2. The Pharmacological Basis of Therapeutics, 8th ed. Gilman et al, eds. Permagon Press/McGraw Hill pg 477
  3. Saunders Manual of Medical Practice, Rakel (ed), WB Saunders, Philadelphia, 1996, pg 1052
  4. Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998
  5. Kaiser Permanente Northern California Regional Drug Formulary, 1998