Trihexyphenidyl 2mg Tablets
SUMMARY OF PRODUCT CHARACTERISTICS
1 NAME OF THE MEDICINAL PRODUCT
Agitane
Trihexyphenidyl 2 mg Tablets
2 QUALITATIVE AND QUANTITATIVE COMPOSITION
Trihexyphenidyl Hydrochloride - 2.00 mg
3 PHARMACEUTICAL FORM
Tablets
4 CLINICAL PARTICULARS
4.1 Therapeutic indications
AGITANE is indicated in the management of the symptoms of postencephalitic arteriosclerotic and idiopathic Parkinsonism and also to control extrapyramidal disorders which may be caused by certain drugs acting on the central nervous system, such as phenothiazines and reserpine. (These include tremor, rigidity and increased salivation which are commonly encountered in the disease; also dyskinesia manifested by spastic contractions and involuntary movements and akathisia characterised by troublesome restlessness. Through decreasing sialorrhoea it is especially valuable as an adjunct in the treatment of arteriosclerotic Parkinsonism).
AGITANE reduces the rigidity of muscle spasm.
4.2 Posology and method of administration
Adults:
In all patients alterations in dosage either upward or downwards should only be by small increments over a period of days. At the commencement of therapy the dose should be 1 mg on the first day, 2 mg on the second day and thereafter by increments of 2 mg per day at 3-5 day intervals, continued until the optimum dose is reached. The maximum daily dose is 20mg.
The relationship of AGITANE therapy with meals will vary according to the reaction of the patient. If when taken after meals thirst is induced this can be allayed by chewing gum, peppermints or drinking water. Should AGITANE tend to dry the mouth excessively, it is wiser taken before meals unless nausea is troublesome.
The usual dosage for Parkinsonism is 6-10mg per day, however patients, particularly those in the post-encephalitic group may require on average a daily dose of 12-15 mg. This should be given at mealtimes either three or four times a day.
On drug-induced Parkinsonism the normal dose usually lies between 5 mg and 15 mg per day. Some patients have been controlled by as little a 1 mg daily.
Children:
AGITANE is not recommended for children.
The Elderly:
Patients over 60 years of age will be more sensitive and therefore require smaller amounts of AGITANE.
AGITANE tablets are to be taken by mouth.
4.3 Contraindications
Sensitivity to Trihexyphenidyl or to any of the excipients in AGITANE. AGITANE is contra-indicated for patients with glaucoma and is also contraindicated for patients with obstructive disease of the genitourinary and gastrointestinal tracts, particularly in patients with a history of prostatic hypertrophy and prostatism.
4.4 Special warnings and precautions for use
The patient should be under careful observation over the long term. It should be administered with care to avoid allergic or other untoward reactions. Abrupt discontinuation of treatment should be avoided.
Incipient glaucoma may be precipitated by parasympatholytic drugs such as AGITANE.
Hypertension, cardiac, liver or kidney disorders are not contra-indications, but such patients should be followed closely.
AGITANE should be used with caution in patients with glaucoma, obstructive disease of the gastro-intestinal or genito-urinary tracts, and in elderly males with possible prostatic hypertrophy.
Trihexyphenidyl may be the subject of abuse due to its euphoric effect.
4.5 Interaction with other medicinal products and other forms of interaction
Increased antimuscarinic side-effects such as dry mouth, urine retention and constipation may occur with concomitant use of other antimuscarinics, nefopam, disopyramide, amantidine, antihistamines, phenothiazines, tricyclic anidepressants and MAOIs. Concomitant use with other antimuscarines may also lead to confusion in the elderly. Antagonism of effect with parasympathomimetics. Antimuscarinics antagonize the gastro-intestinal effects of metoclopramide and domperidone. Reduced absorption of ketoconazole. The effect of sublingual nitrates may be reduced if dry mouth prevents dissolution under the tongue.
4.6 Pregnancy and lactation
Problems in humans have not been documented and it is not known whether the drug is excreted in breast milk. However, lactation may be inhibited.
4.7 Effects on ability to drive and use machines
May affect performance at skilled tasks (e.g. driving).
4.8 Undesirable effects
Dryness of mouth, gastro-intestinal disturbances, blurring of vision, dizziness and mild nausea or nervousness will be experienced by 30-50% of all patients. These reactions tend to become less pronounced as treatment continues.
Patients with a history of drug idiosyncrasies may exhibit reactions of mental confusion, agitation, or nausea and vomiting. Such patients should be allowed to develop a tolerance using the smaller initial dose, with gradual increases until the effective level is reached.
Less common side effects include: urinary retention, tachycardia, hypersensitivity and with high doses in susceptible patients, confusion, excitement, agitation, hallucinations, insomnia and psychiatric disturbances which may neccesitate discontinuation of treatment; impaired memory also reported.
4.9 Overdose
No specific antidote. Gastric lavage, emetic, high enema. Usual general treatment plus cold compresses and forcing of fluid are mandatory. Atropine antagonists may be useful.
5 PHARMACOLOGICAL PROPERTIES
5.1 Pharmacodynamic properties
It is believed that AGITANE acts through partially blocking central (striatal) cholinergic receptors. Trihexyphenidyl has a direct anti-spasmodic effect on smooth muscles and in small doses depresses the Central Nervous System but larger doses may cause cerebral excitation.
5.2 Pharmacokinetic properties
Absorbed in the gastro-intestinal tract with an onset of action of 1 hours and a duration of action of 6 to 12 hours.
5.3 Preclinical safety data
Not applicable.
6.1 List of excipients
Lactose Maize Starch
Pregelatinised maize starch Sodium starch glycollate Magnesium Stearate
6.2 Incompatibilities
None known.
6.3 Shelf life
36 months all pack sizes.
6.4 Special precautions for storage
Store below 25°C in a dry place.
Protect from light.
6.5 Nature and contents of container
High density polystyrene with polythene lids and/or polypropylene containers with polypropylene or polythene lids and polyurethane/polythene inserts.
Pack sizes: 28, 30, 50, 56, 60, 84, 100, 250, 500 & 1000.
6.6 Special precautions for disposal
No special instructions.
MARKETING AUTHORISATION HOLDER
7
Chelonia Healthcare Limited 11 Boumpoulinas Street,
3rd floor, 1060 Nicosia Cyprus
8 MARKETING AUTHORISATION NUMBER(S)
PL 33414/0014
9 DATE OF FIRST AUTHORISATION/RENEWAL OF THE
AUTHORISATION
26/11/1987 / 15/09/2003
10 DATE OF REVISION OF THE TEXT
27/11/2008