More from Tripar
Other strengths and forms by Opsonin Pharma Limited
Indications & Uses
Tripar is indicated for:
Pharmacology
Trihexyphenidyl blocks muscarinic acetylcholine receptors without much selectivity, though it does show a stronger preference for the M1 subtype. Research in living systems indicates it binds more readily to muscarinic receptors in the cerebral cortex (a central site) than to those found elsewhere in the body. Some studies also point to an effect on nicotinic acetylcholine receptor signalling, which may indirectly boost dopamine release in the striatum. Despite its established value in easing the symptoms of Parkinson's disease and related movement disorders, exactly how this anticholinergic drug works is still not fully understood.
Dosage Reference
Reference Information Only
Dosages shown are general references from official sources. Always consult your doctor or pharmacist for personalized dosing.
Adults:
Dosing needs to be individualized for each patient. The starting dose should be kept low and increased gradually, especially in patients over 60 years of age. Whether Trihexyphenidyl is best taken before or after meals should be decided based on how the patient responds. Postencephalitic patients, who tend to be more prone to excessive salivation, may prefer taking it after meals and may also need small amounts of atropine, which can sometimes be a useful additional treatment in such cases. If Trihexyphenidyl tends to dry the mouth excessively, it may be better to take it before meals, unless doing so causes nausea. If taken after meals, any thirst it induces can sometimes be relieved with mint candies, chewing gum or water. Abruptly stopping treatment for Parkinsonism may cause a sudden worsening of Parkinsonism symptoms, so abrupt withdrawal should be avoided. Abrupt withdrawal of treatment may also result in neuroleptic malignant syndrome (NMS).
Idiopathic Parkinsonism: As initial therapy for parkinsonism, a dose of 1 mg of Trihexyphenidyl may be given on the first day. The dose may then be increased in 2 mg increments at intervals of three to five days, until a total of 6 to 10 mg is given daily. The total daily dose depends on what is found to be the optimal level for the patient. Many patients get the most benefit from a daily total of 6 to 10 mg, but some patients, particularly those in the postencephalitic group, may need a total daily dose of 12 to 15 mg.
Drug Induced Parkinsonism: The size and frequency of the Trihexyphenidyl dose needed to control extrapyramidal reactions to commonly used tranquilizers, notably the phenothiazines, thioxanthenes and butyrophenones, must be worked out for each patient. The total daily dosage usually ranges between 5 and 15 mg, although in some cases these reactions have been satisfactorily controlled with as little as 1 mg daily. It may be advisable to begin therapy with a single 1 mg dose. If the extrapyramidal symptoms are not controlled within a few hours, later doses may be gradually increased until satisfactory control is achieved. Satisfactory control can sometimes be reached more quickly by temporarily lowering the dose of the tranquilizer when starting Trihexyphenidyl therapy, and then adjusting the doses of both drugs until the desired calming effect is maintained without the onset of extrapyramidal reactions. It is sometimes possible to keep the patient on a reduced Trihexyphenidyl dose once the reactions have been under control for several days. There have been reports of these reactions staying in remission for long periods after Trihexyphenidyl therapy was stopped.
Concomitant use with Levodopa: When Trihexyphenidyl is used concomitantly with levodopa, the usual dose of each may need to be lowered. Careful adjustment is needed, depending on side effects and the degree of symptom control achieved. A Trihexyphenidyl dosage of 3 to 6 mg daily, given in divided doses, is usually enough.
Concomitant use with other Parasympathetic Inhibitors: Trihexyphenidyl may be substituted, in whole or in part, for other parasympathetic inhibitors. The usual approach is partial substitution at first, with the other medication progressively reduced as the dose of Trihexyphenidyl is increased.
The total daily intake of Trihexyphenidyl tablet is best tolerated when divided into 3 doses and taken at mealtimes. Higher doses (above 10 mg daily) may be divided into 4 parts, with 3 doses given at mealtimes and the fourth at bedtime.
Use in children: Safety and effectiveness in pediatric patients have not been established.
Side Effects
Minor side effects such as dryness of the mouth, blurred vision, dizziness, mild nausea, or nervousness are experienced by 30 to 50 percent of all patients. These sensations, however, are much less troublesome with Parkifen than with belladonna alkaloids and are usually less disturbing than unalleviated parkinsonism. Such reactions tend to become less pronounced, and even disappear, as treatment continues. Even before these reactions have subsided on their own, they can often be controlled through careful adjustment of dosage form, drug amount, or interval between doses. Isolated instances of suppurative parotitis secondary to excessive dryness of the mouth, skin rashes, dilatation of the colon, paralytic ileus, and certain psychiatric manifestations such as delusions, hallucinations, and paranoia, all of which may occur with any of the atropine-like drugs, have been reported rarely with Parkifen. Potential side effects associated with the use of any atropine-like drugs, including Parkifen, include cognitive dysfunctions such as confusion and memory impairment, constipation, drowsiness, urinary hesitancy or retention, rapid heartbeat, dilation of the pupil, increased pressure within the eye, choreiform movements, weakness, vomiting, and headache. Worsening of parkinsonism with abrupt withdrawal of treatment has been reported. Neuroleptic malignant syndrome with abrupt withdrawal of treatment has also been reported. The occurrence of angle-closure glaucoma in patients receiving Parkifen has been reported, with blindness reported in some cases. Paradoxical sinus bradycardia, dry skin, and cycloplegia have also been reported. In addition to the adverse events seen in adults, the following adverse events have been reported in the literature in pediatric patients: hyperkinesia, psychosis, forgetfulness, weight loss, restlessness, chorea, and sleep alterations.
Cautions & Contraindications
Warnings & Precautions
Patients being treated with Parkifen should have a gonioscope evaluation before starting therapy, along with close monitoring of intraocular pressure. Anticholinergic drugs can trigger angle closure with a rise in intraocular pressure. If blurred vision develops during treatment, narrow angle glaucoma should be considered as a possible cause, since blindness has been reported from aggravation of this condition. Parkifen should be used with caution in hot weather, particularly when combined with other atropine-like drugs, in patients who are chronically ill, alcoholic, affected by central nervous system disease, or engaged in manual labor in a hot environment. Anhidrosis is more likely to occur when some disturbance of sweating is already present. If signs of anhidrosis appear, hyperthermia should be considered a possibility, and the dose should be reduced so that the body's ability to regulate heat through perspiration is not compromised. Severe anhidrosis and fatal hyperthermia have occurred with anticholinergic use under these conditions. Neuroleptic Malignant Syndrome (NMS): This potentially fatal symptom complex has been reported in association with dose reduction or discontinuation of Parkifen. It presents with hyperpyrexia, muscle rigidity, altered mental status, and signs of autonomic instability, including irregular pulse or blood pressure, tachycardia, diaphoresis, and cardiac dysrhythmias.
Contraindications
Trihexyphenidyl should not be used by anyone who is hypersensitive to it. It is also contraindicated in narrow angle glaucoma, since prolonged use in this condition has been reported to cause blindness.
Pregnancy & Breastfeeding
There are no controlled studies in animals or in pregnant women. Trihexyphenidyl HCI is only recommended during pregnancy when the need is clearly established and the benefit outweighs the risk. It is not known whether this drug passes into human milk. Many drugs do, so care is needed when Trihexyphenidyl HCI is given to a woman who is breastfeeding. Like other anticholinergics, Trihexyphenidyl HCI may reduce milk production. So it should only be used if the expected benefit to the mother is greater than the possible risk to the baby.
⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.
Overdose
In humans, doses of up to 300 mg (5 mg/kg) of Trihexyphenidyl Hydrochloride have been taken without any deaths or after-effects. Still, rare deaths have been reported when an overdose was taken together with other CNS-depressant agents, or in patients whose breathing was already compromised. Blood concentrations of Trihexyphenidyl Hydrochloride in the fatal cases ranged from 0.03 to 0.80 mg/I.
Signs and Symptoms
An overdose produces the typical central symptoms of atropine intoxication (the central anticholinergic syndrome). To make the correct diagnosis, look for the peripheral signs of parasympathetic blockade. These include dilated and sluggish pupils, warm and dry skin, facial flushing, and decreased secretions of the mouth, pharynx, nose and bronchi. Foul-smelling breath, elevated temperature, tachycardia, cardiac arrhythmias, decreased bowel sounds and urinary retention may also be seen. Neuropsychiatric signs may be present as well: delirium, disorientation, anxiety, hallucinations, illusions, confusion, incoherence, agitation, hyperactivity, ataxia, lip smacking and tasting movements, loss of memory, paranoia, combativeness and seizures. The condition can progress to stupor, coma, paralysis, cardiac and respiratory arrest, and death.
Treatment
Acute overdose is treated with symptomatic and supportive therapy. Gastric lavage or other methods to limit absorption should be started. If CNS excitation is seen, a small dose of diazepam or a short-acting barbiturate may be given. Phenothiazines are contra-indicated, because their antimuscarinic action can intensify the toxicity and cause coma. Respiratory support, artificial respiration or vasopressor agents may be necessary. Hyperpyrexia must be reversed, fluid volume replaced and acid-balance maintained. Urinary catheterization may be necessary. It is not known if Trihexyphenidyl Hydrochloride is dialyzable.
⚠️ In an emergency call 999 or go to the nearest hospital emergency department.
Storage
Keep Trihexyphenidyl Hydrochloride in a dry place, at a temperature not above 30ºC. Protect it from light.
Drug Interactions
Common questions about Tripar 100 mg
What is Tripar 100 mg Syrup?
Tripar 100 mg Syrup is a medicine that contains Trihexyphenidyl Hydrochloride. It is made by Opsonin Pharma Limited. It belongs to the Antiparkinson drugs group of medicines.
What is Tripar used for?
Tripar is used for: Parkinson's Disease.
What are the side effects of Tripar?
Minor side effects such as dryness of the mouth, blurred vision, dizziness, mild nausea, or nervousness are experienced by 30 to 50 percent of all patients. These sensations, however, are much less troublesome with Parkifen than with belladonna alkaloids and are usually less disturbing than unalleviated parkinsonism.
Can I take Tripar during pregnancy or while breastfeeding?
There are no controlled studies in animals or in pregnant women. Trihexyphenidyl HCI is only recommended during pregnancy when the need is clearly established and the benefit outweighs the risk. Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.
What happens if I take too much Tripar?
In humans, doses of up to 300 mg (5 mg/kg) of Trihexyphenidyl Hydrochloride have been taken without any deaths or after-effects. Still, rare deaths have been reported when an overdose was taken together with other CNS-depressant agents, or in patients whose breathing was already compromised. In an emergency call 999 or go to the nearest hospital emergency department.
How should I store Tripar?
Keep Trihexyphenidyl Hydrochloride in a dry place, at a temperature not above 30ºC. Protect it from light.
Can I take other medicines with Tripar?
Some medicines can interact with Trihexyphenidyl Hydrochloride, for example: Levodopa, Dextromethorphan + Phenylephrine + Triprolidine, Imipramine Hydrochloride. Tell your doctor or pharmacist about every medicine you take.
Do I need a prescription for Tripar?
Tripar is a prescription (Rx) medicine. Take it as your doctor advises.