Artane (trihexyphenidyl hydrochloride) is a centrally acting anticholinergic agent indicated for the treatment of parkinsonism and drug-induced extrapyramidal symptoms. It functions as a competitive antagonist at muscarinic acetylcholine receptors, effectively counteracting the relative cholinergic excess that contributes to the motor dysfunction seen in these conditions. By modulating neurotransmitter balance in the basal ganglia, Artane helps alleviate tremor, rigidity, and sialorrhea, thereby improving functional mobility and quality of life for patients. Its well-established efficacy profile makes it a cornerstone in the management of these movement disorders.

Features

• Active Pharmaceutical Ingredient: Trihexyphenidyl Hydrochloride
• Available Dosage Forms: 2 mg and 5 mg immediate-release tablets; 5 mg sustained-release capsules; Elixir (2 mg/5mL)
• Pharmacologic Class: Antimuscarinic Agent
• Mechanism of Action: Competitive antagonism of central and peripheral muscarinic acetylcholine receptors
• Half-life: Approximately 3-12 hours (dose-dependent)
• Bioavailability: High oral bioavailability
• Metabolism: Hepatic
• Excretion: Primarily renal

Benefits

• Reduces Parkinsonian Tremor and Rigidity: Effectively diminishes the characteristic resting tremor and muscle stiffness associated with parkinsonism, facilitating smoother and more controlled voluntary movements.
• Manages Drug-Induced Dystonia: Provides rapid relief from acute dystonic reactions, such as torticollis or oculogyric crisis, which can be caused by antipsychotic medications.
• Decreases Sialorrhea: Significantly reduces excessive drooling (hypersalivation), a common and socially debilitating symptom in Parkinson’s disease, by inhibiting salivary gland secretions.
• Improves Functional Mobility: By alleviating key motor symptoms, it enhances a patient’s ability to perform activities of daily living, promoting greater independence.
• Adjunctive Therapy: Serves as an effective add-on therapy to levodopa in Parkinson’s disease, often allowing for lower doses of levodopa and mitigating some of its side effects.

Common use

Artane is primarily prescribed for the management of all forms of parkinsonism, including post-encephalitic, arteriosclerotic, and idiopathic Parkinson’s disease. It is particularly valuable as an adjunctive therapy to levodopa/carbidopa. A second major indication is the treatment of medication-induced extrapyramidal symptoms (EPS), which are adverse reactions to drugs that block dopamine receptors, most commonly first-generation (typical) antipsychotics. These symptoms include drug-induced parkinsonism (characterized by tremor, bradykinesia, and rigidity), akathisia (a subjective feeling of restlessness), and acute dystonic reactions (sustained, painful muscle contractions). It may also be 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 and gradually increased.

• For Parkinsonism: The initial adult dose is 1 mg on the first day. The dose may be increased by 2 mg increments at intervals of 3 to 5 days until a total daily dose of 6 to 10 mg is reached. The total daily dose is usually divided into 3 or 4 administrations. Many patients derive maximum benefit from a total daily dose of 6 to 10 mg, though some may require up to 12-15 mg daily.
• For Drug-Induced EPS: The usual dosage for controlling extrapyramidal disorders is 5 to 15 mg per day, though most patients respond to 1 to 5 mg daily. The initial dose is often 1 mg, which can be increased as needed.
• Elderly Patients: Geriatric patients often require lower dosages due to increased sensitivity to anticholinergic effects and a higher risk of CNS adverse reactions. Initiation at 0.5 to 1 mg daily with very slow titration is recommended.
• Administration: Tablets should be taken orally with or without food. If gastric upset occurs, administration with meals is advised. The sustained-release capsule must be swallowed whole and not crushed, chewed, or divided.

Precautions

Artane should be used with caution in a number of patient populations and conditions.

• Geriatric Patients: Older adults are highly susceptible to confusion, agitation, hallucinations, and CNS depression. They are also at greater risk for developing glaucoma and gastrointestinal obstructive disorders.
• Patients with Glaucoma: Artane can induce pupillary dilation (mydriasis), which can precipitate an acute attack of narrow-angle glaucoma.
• Patients with Prostatic Hypertrophy: Anticholinergics may cause urinary retention and should be used with extreme caution in men with known prostatic enlargement.
• Patients with Gastrointestinal Disorders: Use with caution in individuals with ulcerative colitis, intestinal atony, or obstructive diseases like paralytic ileus, as Artane can decrease gastrointestinal motility.
• Cardiovascular Disorders: May cause tachycardia; caution is advised in patients with cardiac arrhythmias, coronary artery disease, or congestive heart failure.
• Renal or Hepatic Impairment: Dosage adjustment may be necessary in patients with significant kidney or liver disease.
• Mental Health Disorders: Can exacerbate symptoms of psychosis, schizophrenia, or other psychiatric conditions and may induce confusion or excitement.
• 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 and may suppress lactation; a decision should be made to discontinue nursing or discontinue the drug.

Contraindications

Artane is contraindicated in patients with:

• Known hypersensitivity to trihexyphenidyl hydrochloride or any component of the formulation.
• Narrow-angle glaucoma (absolute contraindication).
• Obstructive uropathy (e.g., bladder neck obstruction due to prostatic hypertrophy).
• Obstructive disease of the gastrointestinal tract (e.g., paralytic ileus, pyloric or duodenal obstruction, megacolon, achalasia).
• Myasthenia gravis.
• Severe ulcerative colitis or toxic megacolon.

Possible side effect

Adverse reactions are primarily extensions of its anticholinergic pharmacological activity.

• Central Nervous System: Drowsiness, dizziness, nervousness, insomnia, confusion, agitation, hallucinations, euphoria, memory impairment, headache. These are often dose-related.
• Ocular: Blurred vision, mydriasis (dilated pupils), increased intraocular pressure, photophobia.
• Gastrointestinal: Dry mouth (xerostomia), constipation, nausea, vomiting, paralytic ileus.
• Genitourinary: Urinary hesitancy and retention.
• Cardiovascular: Tachycardia (fast heart rate), palpitations.
• Dermatological: Decreased sweating, which can lead to heat prostration and fever in hot environments, skin rash.
• Other: Weakness, numbness of fingers.

Drug interaction

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

• Other Anticholinergics: Concomitant use with other drugs possessing anticholinergic properties (e.g., antihistamines, tricyclic antidepressants, phenothiazines, disopyramide) can lead to additive therapeutic and toxic effects (e.g., severe constipation, urinary retention, blurred vision, xerostomia).
• Cholinergic Agents: Artane will antagonize the effects of drugs used to treat myasthenia gravis (e.g., neostigmine, pyridostigmine).
• Levodopa: A synergistic effect occurs when used with levodopa; the combination may provide better symptom control in Parkinson’s disease than either agent alone.
• CNS Depressants: May have an additive sedative effect when taken with alcohol, benzodiazepines, opioids, or other sedating drugs.
• Absorption of Other Drugs: By decreasing gastrointestinal motility, Artane may affect the absorption rate of other orally administered drugs.
• Dopamine Antagonists: May diminish the effectiveness of antipsychotic medications (e.g., haloperidol, chlorpromazine) by competing for receptor sites, though it is used to treat their EPS side effects.
• Amantadine: Concomitant use may increase 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. The patient should not take a double dose to make up for the missed one. Maintaining a consistent dosing schedule is important for stable symptom control.

Overdose

Overdosage with Artane produces symptoms of central nervous system stimulation followed by depression, and pronounced peripheral anticholinergic effects.

• Signs and Symptoms: Severe central nervous system disturbances (including confusion, agitation, restlessness, hallucinations, psychosis, seizures, and coma), severe dry mouth, blurred vision, flushed, hot, dry skin, hyperthermia, tachycardia, hypertension, dilated pupils, respiratory depression, circulatory collapse, and paralysis.
• Management: Treatment is primarily symptomatic and supportive. Gastric lavage or activated charcoal may be considered if ingestion was recent. Physostigmine, a cholinesterase inhibitor, may be used as an antidote for severe, life-threatening central anticholinergic effects in a hospital setting, but its use is controversial and requires extreme caution due to its own risk of serious side effects (e.g., seizures, bradycardia). Control hyperthermia with cooling blankets. Manage seizures with benzodiazepines. Support respiration if necessary.

Storage

Store Artane tablets and capsules at room temperature, between 20°C to 25°C (68°F to 77°F), in a tight, light-resistant container. Keep the bottle tightly closed to protect from moisture. Keep all medications out of the reach of children and pets. Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard expired or no-longer-needed medication through a medicine take-back program.

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 medication. Never disregard professional medical advice or delay in seeking it because of something you have read here. The author and publisher are not responsible for any specific health or allergy needs that may require medical supervision or for any adverse effects resulting from the use of information contained herein.

Reviews

• “As a neurologist with over 20 years of experience, Artane remains a fundamental tool in my arsenal for managing drug-induced dystonias. Its rapid onset of action is invaluable in the emergency setting.” – Dr. A. Sharma, MD
• “For my moderate Parkinson’s symptoms, adding a low dose of Artane to my levodopa regimen made a significant difference in controlling my tremor. The dry mouth is noticeable but manageable.” – Patient, 68
• “I prescribe it cautiously in the elderly due to the high risk of confusion, but for younger patients experiencing extrapyramidal side effects from antipsychotics, it is often the most effective choice.” – Psychiatrist
• “The side effect profile is classic for its class, but when titrated correctly, the benefits for motor control far outweigh the inconveniences for most appropriate patients.” – Movement Disorder Specialist