AMANTADINE HYDROCHLORIDE

Posology Parkinson's disease:

Initially 100mg daily for the first week, increasing to 100mg twice daily. The dose can be titrated against signs and symptoms. Doses exceeding 200mg daily may provide some additional relief but may also be associated with increasing toxicity.

A dose of 400mg/day should not be exceeded. The dose should be increased gradually, at intervals of not less than 1 week. Since patients over 65 years of age tend to show lower renal clearance and consequently higher plasma concentrations, the lowest effective dose should be used.

Amantadine acts within a few days but may appear to lose efficacy within a few months of continuous treatment. Its effectiveness may be prolonged by withdrawal for three to four weeks, which seems to restore activity. During this time, existing concomitant antiparkinsonian therapy should be continued, or low dose L-dopa treatment initiated if clinically necessary.

g. half the dose at weekly intervals. 4, “Special warnings and precautions for use”). Combined treatment: any antiparkinson drug already in use should be continued during initial Amantadine treatment. It may then be possible to reduce the other drug gradually.

If increased side effects occur, the dosage should be reduced more quickly. In patients receiving large doses of anticholinergic agents or L-dopa, the initial phase of Amantadine treatment should be extended to 15 days.

Special Populations:

In patients with renal impairment: the dose of amantadine should be reduced. This can be achieved by either reducing the total daily dose, or by increasing the dosage interval in accordance with the creatinine clearance. For example, Creatinine clearance ml/(min) Dose < 15 Amantadine contraindicated.

15 - 35 100mg every 2 to 3 days. > 35 100mg every day. The above recommendations are for guidance only and physicians should continue to monitor their patients for signs of unwanted effects. Method of administration For oral administration.

Amantadine's undesirable effects are often mild and transient, usually appearing within the first 2 to 4 days of treatment and promptly disappearing 24 to 48 hours after discontinuation. A direct relationship between dose and incidence of side effects has not been demonstrated, although there seems to be a tendency towards more frequent undesirable effects (particularly affecting the CNS) with increasing doses.

List of adverse reactions The frequencies of adverse events are ranked according to the following Very common (≥1/10); Common (≥1/100 to <1/10); Uncommon (≥1/1,000 to <1/100); Rare (≥1/10,000 to <1/1,000); Very rare (<1/10,000); Not known (cannot be estimated from the available data).

g. punctate subepithelial opacities which might be associated with superficial punctate keratitis, corneal epithelial oedema, and markedly reduced visual acuity Very common Oedema of ankles, livedo reticularis4, Common Palpitations, orthostatic hypotension Cardiac disorders Very rare Heart insufficiency/failure Common Dry mouth, anorexia, nausea, vomiting, constipation Gastrointestinal disorders Rare Diarrhoea Common Diaphoresis Rare Exanthema Skin and subcutaneous tissue disorders Very rare Photosensitisation Renal and urinary disorders Rare Urinary retention, urinary incontinence 1Pathological gambling, increased libido, hypersexuality, compulsive spending or buying, binge eating and compulsive eating can occur in patients treated with products with a dopaminergic effect, including amantadine (see section “Special warnings and precautions for use”).

2more common when amantadine is administered concurrently with anticholinergic agents or when the patient has an underlying psychiatric disorder. 3reported but their incidence cannot be readily deduced from the literature. 4 usually after very high doses or use over many months.

Reporting of suspected adverse reactions Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit / risk balance of the medicinal product. uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

Amantadine should be used with caution in patients with confusional or hallucinatory states or underlying psychiatric disorders, in patients with liver or kidney disorders, and those suffering from, or who have a history of, cardiovascular disorders.

5, Interactions with other medicaments and other forms of interaction). g. catatonia, confusion, disorientation, worsening of mental status, delirium). Amantadine should not be stopped abruptly in patients who are treated concurrently with neuroleptics.

There have been isolated reports of precipitation or aggravation of neuroleptic malignant syndrome or neuroleptic-induced catatonia following the withdrawal of amantadine in patients taking neuroleptic agents. A similar syndrome has also been reported rarely following withdrawal of amantadine and other anti-parkinson agents in patients who were not taking concurrent psychoactive medication.

Cases of suicidal ideation and behaviour have been reported during treatment with amantadine. Patients should be monitored for signs of suicidal ideation and behaviour and treatment initiated as needed. Patients (and caregivers of patients) should be advised to seek medical advice if any signs of suicidal ideation or behaviour emerge.

As some individuals have attempted suicide with amantadine, prescriptions should be written for the smallest quantity consistent with good patient management. Peripheral oedema Peripheral oedema (thought to be due to an alteration in the responsiveness of peripheral vessels) may occur in some patients during chronic treatment (not usually before four weeks) with amantadine.

This should be taken into account in patients with congestive heart failure. Anticholinergic effects Amantadine has anticholinergic effects, it should not be given to patients with untreated angle closure glaucoma. If blurred vision or other visual problems occur an ophthalmologist should be contacted to exclude corneal oedema.

In case that corneal oedema is diagnosed treatment with amantadine should be discontinued. Impulse control disorders Patients should be regularly monitored for the development of impulse control disorders. Patients and carers should be made aware that behavioural symptoms of impulse control disorders, including pathological gambling, increased libido, hypersexuality, compulsive spending or buying, binge eating and compulsive eating can occur in patients treated with products with a dopaminergic effect, including amantadine.

Dose reduction or tapered discontinuation should be considered if such symptoms develop. Lactose Patients with rare hereditary problems of galactose intolerance, the total lactase deficiency or glucose galactose malabsorption should not take this medicine.

3. 1. • Individuals subject to convulsions. • A history of gastric ulceration. • Severe renal disease. • Pregnancy.