TRIHEXONEX-2 (TRIHEXYPHENIDYL HCL. TABLETS)

DESCRIPTION

Trihexyphenidyl hydrochloride is a synthetic antispasmodic drug available in the following forms: Tablets, 2 mg and 5 mg. It is designated chemically 1-Piperidinepropanol,α-cyclohexyl-α-phenyl-, hydrochloride.

DOSAGE

Children 2 to 17 years old: Dystonia in cerebral palsy. Initial: 0.1 to 0.2 mg/kg/day in three divided doses for 1 week; increase by 0.05 to 0.3 mg/kg/day in three divided doses for the second week; thereafter, titrate up weekly by 0.05 to 0.5 mg/kg/day in three divided doses as clinically tolerated. Maximum dose: 0.75 mg/kg/day

CLINICAL PHARMACOLOGY

The exact mechanism of action in parkinsonian syndromes is not precisely understood, but it is known that trihexyphenidyl blocks efferent impulses in parasympathetically innervated structures like smooth muscles (spasmolytic activity), salivary glands, and eyes (mydriasis). In higher doses direct central inhibition of cerebral motor centers may contribute.

INDICATIONS

This drug is indicated as an adjunct in the treatment of all forms of parkinsonism (postencephalitic, arteriosclerotic, and idiopathic). It is often useful as adjuvant therapy when treating these forms of parkinsonism with levodopa. Additionally, it is indicated for the control of extrapyramidal disorders caused by central nervous system drugs such as the dibenzoxazepines, phenothiazines, thioxanthenes, and butyrophenones.

CONTRA INDICATIONS

Hypersensitivity to trihexyphenidyl. Narrow angle glaucoma Ileus ,Caution : Patients with obstructive diseases of the urogenital tract, patients with a known history of seizures and those with potentially dangerous tachycardia. Patients under 18 yrs. of age should not be treated due to a lack of clinical experience.

SIDE EFFECTS

Peripheral side effects: blurred vision, dry mouth, impaired sweating, abdominal discomfort, and constipation are frequent. Tachycardia may be noted. Allergic skin reactions may occur. Parenteral use may cause orthostatic hypotension. Eyes: trihexyphenidyl causes mydriasis with or without photophobia. It may precipitate narrow angle glaucoma. Tolerance may develop during therapy which requires dose adjustments.

DRUG INTERACTIONS

Other anticholinergic drugs (e.g. spasmolytics, antihistamines, TCAs) : Side effects of trihexyphenidyl may be increased. Quinidine : Increased anticholinergic action (particular on AV conduction). Antipsychotics : Long term use of trihexyphenidyl may mask or increase the risk of tardive dyskinesia. Pethidine (meperidine) : Central effects and side effects of pethidine may be increased. Metoclopramide : Action of metoclopramide is decreased. Alcohol : Risk of serious intoxication.

AVAILABILITY

TRIHEXONEX-2 is available in strips  of  ten  capsules containing TRIHEXYPHENIDYL HCL TABLETS.