Artane

Artane (trihexyphenidyl) is an antispasmodic drug of the antimuscarinic class.

How does it work?

Trihexyphenidyl belongs to the list of potent substances. It has a central and peripheral m-anticholinergic effect. The drug has an antispasmodic effect, has a direct inhibitory effect on the parasympathetic nervous system, as well as a muscle relaxant effect on smooth muscles and reduces the secretion of especially salivary and bronchial glands, and reduces perspiration. It has a slight effect on the secretion of the pancreas and bile.

Indications

Artane is used to treat Parkinson’s disease, extrapyramidal disorders caused by the use of antipsychotics, Little’s disease, spastic paralysis caused by damage to the extrapyramidal system. The drug in some cases reduces tone and improves movement with paresis of a pyramidal nature.

Instructions for use

The drug is used by adults only. The pills are taken orally, regardless of meals. It is recommended to take a tablet with a sufficient amount of liquid (150-200 ml). With hypersalivation, the pills should be taken after meals. If a patient experinces dryness of the oral mucosa, the pills are taken before meals.

The dose must be selected individually. Start with the lowest dose, increasing it to the minimum effective one. In parkinsonism: the initial dose is 1 mg per day. Every 3-5 days, the dose is gradually increased by 1-2 mg per day; the dose is increased to 6-10 mg per day, depending on the patient’s response to obtain the optimal therapeutic effect.

Some patients may need to take 12-15 mg per day or more. Patients with postencephalitic parkinsonism may be resistant to the drug and require large doses. Treatment of drug-induced extrapyramidal disorders: 5-10 mg of trihexyphenidyl per day, depending on the severity of the symptoms. In some cases, 1 mg daily may be sufficient. Treatment should be completed gradually, reducing the dose of trihexyphenidyl for 1-2 weeks until it is completely canceled. Abrupt withdrawal of the drug can lead to a sudden deterioration in the patient’s condition due to exacerbation of the symptoms of the disease. The duration of treatment is determined by the doctor individually in each case.

Elderly patients over 65 years of age take trihexyphenidyl in minimal doses (1-2 mg) under the control of cognitive functions and mental state.

If you take other drugs to treat parkinsonism, trihexyphenidyl dose reduction is necessary. With the simultaneous administration of levodopa, the dosage of both drugs must be reduced – usually 3-6 mg of trihexyphenidyl per day, divided into 2 doses.

Contraindications

Do not take Artane if you have any of the following conditions:

• hypersensitivity to any of the components of the drug;
• mechanical stenosis of the gastrointestinal tract;
• megacolon;
• angle-closure glaucoma;
• urinary retention;
• prostatic hyperplasia;
• tachyarrhythmias;
• acute poisoning with alcohol, drugs or psychotropic drugs, including opioids;
• tardive dyskinesia (trihexyphenidyl can provoke or aggravate the course of tardive dyskinesia);
• pregnancy and breastfeeding;
• children under 18 years of age;
• sucrose/isomaltase deficiency, fructose intolerance, glucose-galactose malabsorption.

Precautions

Take the drug with caution if you have any of the following conditions:

• tachycardia;
• arterial hypertension;
• prostatic hyperplasia;
• psychotic and manic disorders;
• dementia;
• acute myocardial infarction;
• myasthenia gravis,
• glaucoma;
• elderly patients;
• patients with heart disease, decompensated kidney or liver diseases, obstructive diseases of the gastrointestinal tract or urinary tract.

Side effects

Artane can cause the following adverse events:

• Central nervous system: increased nervous irritability, euphoria, psychomotor agitation, agitation, headache, dizziness, irritability, delirium, hallucinations, increased fatigue, decreased ability to concentrate, psychosis, anxiety, increased sensitivity, insomnia, involuntary movements in the form of dyskinesias (especially in patients who take levodopa drugs);
• Effects due to anticholinergic activity: dry oral mucosa, paresis of accommodation, increased intraocular pressure, mydriasis, visual impairment; decreased sweating, constipation, urinary retention, difficulty urinating, tachycardia, bradycardia;
• Digestive system: nausea, vomiting;
• Allergic reactions: skin rashes, photophobia;
• Other: purulent mumps (due to a decrease in saliva), flushing of the skin, decreased muscle tone, drug dependence.

Pregnancy and breastfeeding

The use of Artane during pregnancy and breastfeeding is contraindicated in order to exclude the possible risk of toxic effects on the fetus and newborn, as well as in the absence of reliable information regarding the use of the drug during pregnancy, its ability to penetrate the placental barrier, excretion with breast milk and the effect on the fetus and newborn.

If it is necessary to use the drug during lactation, breastfeeding should be discontinued.

Overdose

Symptoms: the first manifestations of intoxication are redness of the skin, facial flushing, dry skin and mucous membranes, dry mouth, swallowing, rapid breathing, tachycardia, high blood pressure, nausea, vomiting, fever, dilated pupils, rashes on the face and upper torso, causeless euphoria, atactic gait. Excitement develops into a delirious state with severe visual hallucinations. In severe overdose: coma, cardiovascular and respiratory failure, death.

Treatment: it is necessary to wash the stomach as soon as possible and use other possible methods to reduce the absorption of the drug, cold compresses, heavy drinking. Hemodialysis and hemoperfusion are indicated only during the first hours after poisoning. There is no specific antidote. Heart complications are treated with sodium bicarbonate or sodium lactate, convulsions — with diazepam, delirium — with physostigmine.

Interaction with other drugs

• Drugs that inhibit the central nervous system increase the inhibitory effects on the central nervous system when taken with trihexyphenidyl;
• Anticholinergics, preparations with anticholinergic activity, monoamine oxidase inhibitors (MAOs) enhance the anticholinergic effect of trihexyphenidyl and cause gastrointestinal disturbances, fever, hyperthermia;
• Trihexyphenidyl attenuates the effects of metoclopramide and domperidone;
• The simultaneous use of trihexyphenidyl with antihistamines can cause undesirable reactions associated with increased anticholinergic action;
• Quinidine can enhance the anticholinergic effect on cardiac activity (inhibition of atrioventricular conduction);
• Trihexyphenidyl reduces the effect of nitrates used sublingually;
• Nefopam and antimuscarinic drugs, including those used by inhalation, may increase the frequency and severity of anticholinergic side effects, such as dry mouth, constipation, drowsiness;
• The effect of trihexyphenidyl can be increased by amantadine, H1-histamine receptor blockers (diphenhydramine, promethazine, clemastine), phenothiazine derivatives (chlorpromazine, alimemazine), tricyclic antidepressants (imipramine, amitriptyline);
• Trihexyphenidyl enhances the metabolism of chlorpromazine;
• Ketoconazole causes a decrease in the absorption of an orally administered drug;
• Under the influence of reserpine, the antiparkinsonian effect of trihexyphenidyl decreases, which leads to an increase in parkinsonism syndrome;
• When used in combination with other antiparkinsonian drugs (for example, levodopa), the dose of trihexyphenidyl should be significantly reduced since such a combination can enhance dyskinesias, especially at the beginning of treatment, while the absorption and Cmax of levodopa in the blood plasma are reduced;
• Dyskinesia is enhanced with the simultaneous administration of tranquilizers and trihexyphenidyl;
• Trihexyphenidyl and parasympathomimetic drugs (pilocarpine, carbachol, neostigmine) are antagonists, therefore, they cannot be used together due to an increase in antimuscarinic side effects;
• Cannabinoids, barbiturates, opiates, alcohol can cause additive effects when combined with trihexyphenidyl.

Special instructions

Since the use of Artane in some cases can last for a long time, the patient should be carefully monitored for a long time to avoid allergic or other undesirable reactions. Treatment cannot be stopped suddenly. At the end of treatment or in the case of the initiation of alternative treatment, the dose of trihexyphenidyl should be reduced gradually. The use of trihexyphenidyl can provoke early glaucoma. Intraocular pressure should be periodically monitored.

The drug should be used with extreme caution in elderly patients. In addition, impaired memory and thinking can develop in such patients.

When using large doses of the drug or when treating patients with predisposing factors (atherosclerosis, advanced age, or patients who have previously developed idiosyncrasy for any drug), mental disorders (unnatural mood increase, agitation, increased irritability), vomiting, or nausea may appear. In these cases, it is necessary to stop treatment.

The drug should not be abruptly withdrawn in patients on long-term therapy.

Drug abuse is possible due to its euphoric or hallucinogenic properties.

If a dry mouth occurs when taking the drug, it is advisable to take the pills before meals.

During long-term treatment, the severity of adverse reactions due to anticholinergic action decreases.