SYNASTONE

Treatment goals and discontinuation:

Before initiating treatment with Synastone 50mg/ml, solution for injection, a treatment strategy including treatment duration and treatment goals should be agreed together with the patient in accordance with pain management guidelines.

During treatment, there should be frequent contact between the physician and the patient to evaluate the need for continued treatment, consider discontinuation and to adjust dosages if needed. 4). 4).

Method of administration:

Intramuscular, intravenous or subcutaneous injection. Volumes greater than 2ml given intramuscularly may need to be in divided doses at different sites.

Adults:

Initially 10-20mg per day, increasing by 10-20mg per day until there are no signs of withdrawal or intoxication. This must be managed by physicians with suitable experience. The initial dose, safe dosage increments and the establishment of a dose that prevents withdrawal symptoms needs to be individualised.

The degree of tolerance or neuroadaptation, any additional consumption of oral methadone or other opiates and the cumulative potential of methadone treatment (as opposed to shorter acting opiates), along with the general health of the patient must be taken into account.

Typical doses for heavily-addicted users can be fatal to those without such neuroadaptation. The usual dose of injectable methadone, when the addict is stabilised may need to exceed 100mg daily in order to prevent symptoms of opiate withdrawal.

The aims of treatment should include allowing patients to reduce any criminality and improve their health and social productivity.

Elderly and debilitated patients:

If repeated doses are required, use with caution due to the long plasma half- life. There may be a greater risk of respiratory depression, with or without any associated renal or hepatic impairment in this age group.

Children:

As methadone has not been studied in children, it should not be used in children under the age of 16 years.

Methadone is associated with undesirable effects similar to other opioid analgesics. There are no modern clinical studies available that can be used to determine the frequency of undesirable effects. Therefore, all the undesirable effects listed are classed as “frequency unknown”.

Endocrine Disorders:- Hyperprolactinaemia. Metabolism and nutrition disorders:- Hypoglycaemia. 4), confusion, mood change including euphoria and dysphoria, hallucinations, restlessness, sleep disturbances. Nervous System Disorders:- Drowsiness, dizziness, vertigo.

Eye Disorders:- Dry eyes, visual disturbances such as miosis, nystagmus1, strabismus1, visual acuity reduced1. Cardiac Disorders:- Bradycardia, tachycardia, palpitations, QT prolongation, torsades de pointes. Vascular Disorders:- Orthostatic hypotension.

9 overdose), central sleep apnoea syndrome, dry nose. Gastrointestinal Disorders:- Nausea, vomiting (particularly at the start of treatement), constipation, biliary spasm, dry mouth. Skin & Subcutaneous tissue Disorders:- Sweating, facial flushing, rashes (urticaria, pruritus), oedema.

Musculoskeletal, Connective Tissue & Bone Disorders:- Muscle rigidity Renal & Urinary Disorders:- Micturition difficulties, urinary retention, ureteric spasm Reproductive System & Breast Disorders:- Decreased libido, dysmenorrhoea, amenorrhoea, sexual dysfunction General Disorders & Administration Site Conditions:- Uncommon: drug withdrawal syndrome Not known: hypothermia 1Visual effects have been reported in infants and children exposed to methadone during pregnancy.

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.

Opioid Use Disorder (abuse and dependence) Methadone is an opioid analgesic and is highly addictive in its own right. It is controlled under the Misuse of Drugs Act 1971 (Schedule 2). It has a long half-life and can therefore accumulate.

A single dose which will relieve symptoms may, if repeated on a daily basis, lead to accumulation and possible death. As with other opioids, tolerance, physical, and/or psychological dependence may develop upon repeated administration of methadone.

It is important that patients only use medicines that are prescribed for them at the dose they have been prescribed and do not give this medicine to anyone else. Abuse or intentional misuse of Synastone 50mg/ml, solution for injection may result in overdose and/or death.

, major depression, anxiety and personality disorders). , too early requests for refills). This includes the review of concomitant opioids and psycho-active drugs (like benzodiazepines). For patients with signs and symptoms of OUD, consultation with an addiction specialist should be considered.

Drug withdrawal syndrome Prior to starting treatment with any opioids, a discussion should be held with patients to put in place a withdrawal strategy for ending treatment with methadone hydrochloride. The decision to maintain a patient on a long-term opioid prescription should be an active decision agreed between the clinician and patient with review at regular intervals (usually at least three-monthly, depending on clinical progress).

Drug withdrawal syndrome may occur upon abrupt cessation of therapy or dose reduction. When a patient no longer requires therapy, it is advisable to taper the dose gradually to minimise symptoms of withdrawal. Tapering from a high dose may take weeks to months.

The opioid drug withdrawal syndrome is characterised by some or all of the following: restlessness, lacrimation, rhinorrhoea, yawning, perspiration, chills, myalgia, mydriasis and palpitations. Other symptoms may also develop including irritability, agitation, anxiety, hyperkinesia, tremor, weakness, insomnia, anorexia, abdominal cramps, nausea, vomiting, diarrhoea, increased blood pressure, increased respiratory rate or heart rate.

When using injectable methadone in the treatment of opioid addiction, the following are contraindicated: 1. Patients not already receiving methadone (because of the high methadone concentration). 2. Patients with known hypersensitivity to methadone.

3. Patients with respiratory depression and obstructive airways disease. 4. Use during an acute asthma attack. 5. Concurrent administration with monoamine oxidase inhibitors or within 2 weeks of discontinuation of treatment with them. 6.

Phaeochromocytoma. Opiates may induce the release of endogenous histamine and stimulate catecholamine release. 7. Risk of paralytic ileus. 8. Comatose patients.