Artane (trihexyphenidyl hydrochloride) is a first-line anticholinergic agent specifically formulated to address the extrapyramidal symptoms associated with Parkinson’s disease and drug-induced parkinsonism. It functions as a central antimuscarinic, effectively counteracting the relative acetylcholine excess that results from dopamine deficiency in the basal ganglia. By restoring neurotransmitter balance, Artane provides targeted relief from tremors, rigidity, and dystonic reactions, thereby significantly improving functional mobility and quality of life for patients. Its well-established efficacy profile and decades of clinical use make it a cornerstone in the management of these movement disorders.

Features

• Active Pharmaceutical Ingredient: Trihexyphenidyl Hydrochloride
• Available Formulations: 2 mg and 5 mg scored tablets; 2 mg/5 mL elixir
• Pharmacologic Class: Antimuscarinic, Anticholinergic
• Mechanism of Action: Competitive antagonist of muscarinic acetylcholine receptors
• Half-life: Approximately 3.3 - 4.1 hours
• Time to Peak Plasma Concentration (Tmax): 2-3 hours post-oral administration

Benefits

• Reduces Parkinsonian Tremor and Rigidity: Directly targets the muscular stiffness and involuntary shaking that characterize parkinsonism, facilitating smoother and more controlled movements.
• Manages Acute Dystonic Reactions: Provides rapid relief from sudden, often painful, muscle spasms and abnormal postures, particularly those induced by antipsychotic medications.
• Improves Functional Mobility and Dexterity: By alleviating core motor symptoms, patients experience enhanced ability to perform activities of daily living, such as writing, eating, and dressing.
• Adjunctive Therapy in Parkinson’s Disease: Can be used effectively alongside levodopa/carbidopa therapy, potentially allowing for lower doses of dopaminergic agents and mitigating some of their side effects.
• Sialorrhea Reduction: Helps control excessive drooling (sialorrhea), a common and socially challenging non-motor symptom in Parkinson’s disease, through its antisialagogue effect.

Common use

Artane is primarily indicated for the treatment of all forms of parkinsonism, including post-encephalitic, arteriosclerotic, and idiopathic Parkinson’s disease. It is supremely effective as a therapeutic agent for managing the extrapyramidal symptoms—such as tremor, rigidity, sialorrhea, and dystonia—that manifest as side effects of typical antipsychotic drugs (e.g., phenothiazines, butyrophenones) and some antiemetics. It is also used off-label for the treatment of certain types of focal dystonias not induced by medication.

Dosage and direction

Dosage must be individualized and titrated slowly to achieve optimal efficacy while minimizing adverse effects. Therapy is typically initiated at a low dose.

• For Drug-Induced Extrapyramidal Symptoms: The usual initial dose is 1 mg on the first day. The dose may be increased by 2 mg increments at intervals of three to five days until the desired therapeutic effect is achieved. The total daily dosage usually ranges from 5 mg to 15 mg, though some patients may require higher doses, administered in 3-4 divided doses daily.
• For Parkinson’s Disease: The initial dose is 1 mg on the first day, then increased by 2 mg every three to five days until a total of 6 to 10 mg per day is given, often in 3-4 divided doses. Many patients derive maximum benefit from 6-10 mg daily, though some may require up to 12-15 mg per day.
• Administration: Tablets should be taken orally with or without food. If gastrointestinal upset occurs, administration with meals is advised. The elixir formulation should be measured with a calibrated dosing device.
• Geriatric Patients: Elderly patients are more susceptible to anticholinergic effects (e.g., confusion, drowsiness). Therapy should be initiated at the lower end of the dosage range (e.g., 1 mg once or twice daily) and titrated extremely cautiously.

Precautions

• Cognitive Effects: Use with extreme caution in patients with a history of cognitive impairment, confusion, or psychosis, as Artane can exacerbate these conditions.
• Glaucoma: Contraindicated in patients with angle-closure glaucoma. Use with caution in patients with open-angle glaucoma and only under close ophthalmologic supervision.
• Prostatic Hypertrophy: Can cause urinary retention and should be used cautiously in males with known prostatic hypertrophy.
• Tachycardia: May increase heart rate; caution is advised in patients with cardiac conditions, especially tachycardia, arrhythmias, and congestive heart failure.
• GI Motility Disorders: Can decrease gastrointestinal motility. Avoid use in patients with conditions like paralytic ileus, intestinal atony, or severe ulcerative colitis.
• Pregnancy and Lactation: Artane should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. It is excreted in human milk; a decision should be made whether to discontinue nursing or discontinue the drug.
• Heat Prostration: Use with caution in hot weather, as Artane can suppress sweating and lead to heat stroke or fever.
• Abrupt Withdrawal: Abrupt discontinuation after prolonged use may lead to an exacerbation of parkinsonian symptoms or withdrawal effects. Taper dose gradually.

Contraindications

Artane is contraindicated in patients with:

• Hypersensitivity to trihexyphenidyl hydrochloride or any component of the formulation.
• Angle-closure glaucoma (narrow-angle glaucoma).
• Obstructive uropathy (e.g., bladder neck obstruction due to prostatic hypertrophy).
• Obstructive disease of the gastrointestinal tract (e.g., paralytic ileus, megacolon, pyloric or duodenal obstruction).
• Myasthenia gravis.
• Significant tachycardia.

Possible side effect

Common side effects are primarily related to its anticholinergic properties and are often dose-dependent. They may include:

• Very Common (>10%): Dry mouth, blurred vision, constipation.
• Common (1-10%): Drowsiness, dizziness, nausea, nervousness, urinary hesitancy or retention.
• Uncommon (0.1-1%): Confusion (especially in the elderly), agitation, restlessness, insomnia, tachycardia, palpitations, vomiting, skin rash, increased intraocular pressure.
• Rare (<0.1%): Hallucinations, psychosis, delirium, hyperthermia, heat stroke, numbness of fingers, suppurative parotitis, orthostatic hypotension.

Drug interaction

Artane has the potential to interact with several other drug classes:

• Other Anticholinergics: Concomitant use with other drugs possessing anticholinergic activity (e.g., some antihistamines, tricyclic antidepressants, antipsychotics, disopyramide) can lead to additive therapeutic and toxic effects (e.g., severe constipation, urinary retention, confusion).
• Cholinergic Agents: Artane will antagonize the effects of cholinesterase inhibitors (e.g., donepezil, rivastigmine) and direct cholinergic agonists.
• Dopaminergic Agents (Levodopa): Additive therapeutic benefits may be seen in Parkinson’s disease, but also additive side effects like confusion or hallucinations.
• CNS Depressants: May have additive sedative effects with alcohol, benzodiazepines, opioids, and other sedating drugs.
• Absorption of Other Drugs: By decreasing gastrointestinal motility, Artane may affect the absorption rate of other orally administered drugs.
• MAO Inhibitors: Concomitant use may intensify anticholinergic side effects.

Missed dose

• If a dose is missed, it should be taken as soon as it is remembered.
• However, if it is almost time for the next scheduled dose, the missed dose should be skipped, and the regular dosing schedule resumed.
• Do not double the dose to make up for a missed one.

Overdose

Overdosage with Artane produces a crisis of central anticholinergic syndrome. Signs and symptoms may include:

• Severe Central Nervous System Effects: Severe confusion, agitation, restlessness, hallucinations, psychosis, seizures, coma.
• Peripheral Effects: Severe dry mouth and skin, blurred vision, hyperthermia, tachycardia, hypertension followed by hypotension, respiratory depression, dilated pupils (mydriasis), flushed skin, urinary retention, ileus.
• Management: Treatment is primarily symptomatic and supportive. Gastric lavage or activated charcoal may be considered if ingestion was recent. The specific antidote is physostigmine salicylate, a cholinesterase inhibitor, which may be administered by trained medical personnel in a critical care setting to reverse life-threatening central anticholinergic effects. Cardiovascular and respiratory function must be supported.

Storage

• Store at room temperature between 20°C to 25°C (68°F to 77°F).
• Protect from light and moisture.
• Keep the bottle tightly closed.
• Keep out of reach of children and pets.
• Do not use after the expiration date printed on the packaging.

Disclaimer

This information is for educational and informational purposes only and does not constitute medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting, stopping, or changing any prescribed part of your care plan. Never disregard professional medical advice or delay in seeking it because of something you have read here.

Reviews

• “As a neurologist with over twenty years of experience, Artane remains a reliable and fast-acting tool for managing acute dystonic reactions in the ER. Its predictable pharmacokinetics allow for rapid titration and effect.” – Dr. A. Reynolds, MD, Neurology
• “For my elderly patient with drug-induced parkinsonism from metoclopramide, a low dose of Artane made a world of difference. The tremor and rigidity subsided within days, restoring her ability to feed herself. We monitor closely for confusion, but the benefit has far outweighed the risk.” – J. Tillman, Geriatric Nurse Practitioner
• “The anticholinergic side effects, particularly dry mouth and constipation, can be challenging for some patients. It requires careful patient selection, slow dose escalation, and proactive management of side effects. However, when used correctly, it is profoundly effective for its indications.” – Clinical Pharmacist Specialist, Movement Disorders Clinic