DIAMORPHINE HYDROCHLORIDE Tablet Ref.[9781] Active ingredients: Diamorphine

The risk of respiratory depression and further elevation of CSF pressure is increased if diamorphine is administered to patients with head injuries or raised intracranial pressure. The sedation and pupillary changes produced may interfere with accurate monitoring of the patient.

In patients who already have conditions or drug therapy that interferes with the ability to maintain normal blood pressure, diamorphine may cause hypotension.

Diamorphine should only be given after careful consideration when treating patients with myxoedema or hypothyroidism, adrenocortical insufficiency, toxic psychoses, CNS depression, prostatic hypertrophy or urethral stricture, kyphoscoliosis, acute alcoholism and delirium tremens, severe inflammatory bowel disease and severe diarrhoea.

Care should be taken in treating the elderly and debilitated patients and those with hepatic or renal impairment. A lower dose should be given to these patients.

Tolerance and physical dependence is likely to develop after a few weeks of treatment, but this does not prevent reduction of dosage or discontinuation when considered necessary, and drug abuse is not normally a problem in patients with severe pain. Great caution is required when the drug is used in patients with a known history of drug abuse. Caution in use should be exercised and a reduction in dose may be advisable in the elderly and in the following cases:

• Hypotension.
• Hypothyroidism.
• Depressed respiratory reserve.
• Monoamine oxidase inhibitors (including moclobemide), or within two weeks of their withdrawal.
• Prostatic hypertrophy.
• Hepatic or renal impairment (Avoid or reduce dose).
• Convulsive disorders.

Patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency should not take this medicine.

Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.

Risk from concomitant use of sedative medicines such as benzodiazepines or related drugs:

Concomitant use of Diamorphine hydrochloride tablets and sedative medicines such as benzodiazepines or related drugs may result in sedation, respiratory depression, coma and death. Because of these risks, concomitant prescribing with these sedative medicines should be reserved for patients for whom alternative treatment options are not possible. If a decision is made to prescribe Diamorphine hydrochloride tablets concomitantly with sedative medicines, the lowest effective dose should be used, and the duration of treatment should be as short as possible.

The patients should be followed closely for signs and symptoms of respiratory depression and sedation. In this respect, it is strongly recommended to inform patients and their caregivers to be aware of these symptoms (see section 4.5).

Alcohol: Enhanced sedative and hypotensive effects.

Antidepressants: The use of diamorphine should be avoided or used with caution in patients receiving monoamine oxidase inhibitors (including phenelzine and moclobemide), or within two weeks of their withdrawal.

Anxiolytics, Hypnotics and other CNS Depressants: Sedative effects may be enhanced by simultaneous use of diamorphine.

Mexiletine: The absorption of mexiletine may be markedly depressed and delayed by concurrent use of diamorphine.

Antimuscarinic Activity: The risk of severe constipation and/or urinary retention may be increased by the administration of drugs having anti-muscarinic activity (atropine and synthetic anti-cholinergics).

Sedative medicines such as benzodiazepines or related drugs: The concomitant use of opioids with sedative medicines such as benzodiazepines or related drugs increases the risk of sedation, respiratory depression, coma and death because of additive CNS depressant effect. The dose and duration of concomitant use should be limited (see section 4.4).

There is no evidence of safety in human pregnancy, therefore it is not advisable to administer diamorphine during pregnancy. Use during labour is not advisable due to the risk of respiratory depression in the new-born.

There is limited information on diamorphine levels in breast milk, therefore it is not advisable for patients on high doses of diamorphine to breast-feed.

May cause drowsiness, if affected patients should not drive or operate machinery.

This medicine can impair cognitive function and can affect a patient’s ability to drive safely. This class of medicine is in the list of drugs included in regulations under 5a of the Road Traffic Act 1988. When prescribing this medicine, patients should be told:

• The medicine is likely to affect your ability to drive.
• Do not drive until you know how the medicine affects you.
• It is an offence to drive while under the influence of this medicine.
• However, you would not be committing an offence (called ‘statutory defence’) if:
  • The medicine has been prescribed to treat a medical or dental problem and
  • You have taken it according to the instructions given by the prescriber and in the information provided with the medicine and
  • It was not affecting your ability to drive safely.

• Hallucinations, confusion, mood changes, dysphoria and dependence.
• Headache, vertigo, dizziness and drowsiness.
• Sweating and postural hypotension.
• Miosis.
• Bradycardia, palpitations, tachycardia and facial flushing.
• Constipation, nausea, vomiting and a dry mouth.
• Ureteric or biliary spasm.
• Rashes and pruritis.
• Urinary retention.
• Decrease in libido or potency.
• Difficulty with micturition.
• Hypothermia.
• Respiratory depression and arrest.
• Circulatory depression.
• Cardiac arrest and shock.
• Syncope.
• Anorexia.
• Cramps and taste alternations.
• Insomnia.
• Weakness.

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. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme Website at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

Not applicable.