Drug Action
Trihexyphenidyl exerts its effects by reducing the effects of the relative central cholinergic excess that occurs as a result of dopamine deficiency.
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Drug reference
Trihexyphenidyl exerts its effects by reducing the effects of the relative central cholinergic excess that occurs as a result of dopamine deficiency.
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Parkinson’s disease (if used in combination with co- careldopa or co-beneldopa) ▶BY MOUTH ▶Adult: Maintenance 2–6 mg daily in divided doses, use not recommended because of toxicity in the elderly and the risk of aggravating dementia Parkinsonism | Drug-induced extrapyramidal symptoms (but not tardive dyskinesia) ▶BY MOUTH ▶Adult: 1 mg daily, then increased in steps of 2 mg every 3–5 days, adjusted according to response; maintenance 5–15 mg daily in 3–4 divided doses, not recommended for use in Parkinson’s disease because of toxicity in the elderly and the risk of aggravating dementia; maximum 20 mg per day ▶Elderly: Lower end of range preferable, not recommended for use in Parkinson’s disease because of toxicity in the elderly and the risk of aggravating dementia
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Myasthenia gravis
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Cardiovascular disease. elderly. gastro- intestinal obstruction. hypertension. liable to abuse. prostatic hypertrophy. psychotic disorders. pyrexia. those susceptible to angle-closure glaucoma
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→Appendix 1: trihexyphenidyl
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Anxiety. bronchial secretion decreased. confusion. constipation. delusions. dizziness. dry mouth . dysphagia. euphoric mood. fever. flushing. hallucination. insomnia. memory loss. myasthenia gravis aggravated. mydriasis. nausea. skin reactions. tachycardia. thirst. urinary disorders. vision disorders. vomiting
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Use only if potential benefit outweighs risk.
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Avoid.
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Manufacturer advises caution.
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Use with caution.
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Tablets should be taken with or after food.
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There can be variation in the licensing of different medicines containing the same drug. Forms available from special-order manufacturers include: oral suspension, oral solution Oral solution EXCIPIENTS: May contain Propylene glycol ▶Trihexyphenidyl hydrochloride (Non-proprietary) Trihexyphenidyl hydrochloride 1 mg per 1 ml Trihexyphenidyl 5mg/5ml oral solution | 200 ml P £31.60 DT = £27.47 Tablet ▶Trihexyphenidyl hydrochloride (Non-proprietary) Trihexyphenidyl hydrochloride 2 mg Trihexyphenidyl 2mg tablets | 84 tablet P £13.50 DT = £4.65 Trihexyphenidyl hydrochloride 5 mg Trihexyphenidyl 5mg tablets | 84 tablet P £21.00 DT = £19.48 DOPAMINERGIC DRUGS › CATECHOL-O- Nervous system METHYLTRANSFERASE INHIBITORS
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Avoid abrupt withdrawal in patients taking long-term treatment.
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Driving and skilled tasks May affect performance of skilled tasks (e.g. driving).
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Lower end of range preferable, not
First-line fragment. Read the complete Indications and Dose section above.
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