MINIRIN

What it is

MINIRIN is an injection containing desmopressin acetate 4 micrograms per millilitre. It is presented as a solution for injection, appearing as a clear colourless solution.

Approved indications

— Treatment of ADH-sensitive cranial diabetes insipidus, including treatment of post-hypophysectomy polydipsia and polyuria. — Diagnostic test to establish renal concentrating capacity in adults only, administered intramuscularly. — Increase of factor VIII levels in patients with mild to moderate haemophilia A and von Willebrand's disease undergoing dental or minor surgery, administered by intravenous infusion only. — Treatment of excessive bleeding in patients with congenital or acquired clinical conditions associated with platelet dysfunction characterised by a prolonged bleeding time, except Glanzmann's thrombasthenia or platelet cyclo-oxygenase deficiency.

Dosing overview

For ADH-sensitive cranial diabetes insipidus in adults, the average daily dose is 1 to 4 micrograms by injection. For paediatric patients, the dose is up to 0.4 micrograms daily, usually given as two divided doses. Dosage must be determined for each individual patient and adjusted according to the diurnal pattern of response. For diagnostic testing of renal concentrating capacity in adults, a single dose of up to 4 micrograms is given by intramuscular injection. For haemophilia A and von Willebrand's disease, 0.4 micrograms desmopressin acetate per kilogram of body weight, diluted to 10–100 mL in isotonic saline, is given as slow intravenous infusion over 15–20 minutes, within half an hour before surgery. For bleeding in patients with platelet dysfunction, desmopressin acetate is given at a dose of 0.3 micrograms per kilogram of body weight, diluted to 50 mL in isotonic saline, as a slow intravenous infusion over 30 minutes.

Key safety warnings

The most frequently reported adverse reaction is hyponatraemia, which may cause headache, nausea, vomiting, water intoxication, weight increase, malaise, abdominal pain, muscle cramps, dizziness, confusion, decreased consciousness, generalised or local oedemas, and in severe cases brain oedema, hyponatraemic encephalopathy, convulsions, and coma. MINIRIN should not be used in habitual and psychogenic polydipsia resulting in urine production exceeding 40 mL per kilogram per 24 hours, or in patients with a history of unstable angina pectoris and/or known or suspected cardiac insufficiency and other conditions requiring treatment with diuretics. Due to the risk of development of tachyphylaxis following repeated dosing, alternative haemostatic therapies should be considered in situations where long-term haemostasis is required (active bleeding for more than 2–4 days), including active postoperative bleeding and variceal bleeding in patients with cirrhosis. Post-marketing reports have documented deep vein thrombosis, cerebrovascular accident and disorder (stroke), cerebral thrombosis, myocardial infarction, angina pectoris and chest pain in relation to MINIRIN injections used for haematological indications; considerations should be taken before use in patients with risk factors for or a history of thrombosis, atherosclerotic cardiovascular disease, atherosclerotic cerebrovascular disease or angioplasty. Rare cases of serious hypersensitivity reactions including anaphylactoid shock and reaction have been reported.

Contraindications

MINIRIN is contraindicated in hypersensitivity to desmopressin acetate or any excipients, habitual and psychogenic polydipsia resulting in urine production exceeding 40 mL per kilogram per 24 hours, history of unstable angina pectoris and/or known or suspected cardiac insufficiency and other conditions requiring treatment with diuretics, known hyponatraemia, Syndrome of Inappropriate ADH Secretion (SIADH), and von Willebrand's disease type IIB.

PBS listing

MINIRIN injection is not listed on the PBS. However, MINIRIN tablets (200 micrograms desmopressin acetate), MINIRIN MELT wafers (120 and 240 micrograms), and MINIRIN nasal spray are listed with streamlined authority required restriction.

Regulatory history

MINIRIN desmopressin acetate 4 microgram per millilitre injection was first registered on the Australian Register of Therapeutic Goods (ARTG 40689) on 21 August 1992. The brand has subsequently expanded to include additional formulations: a 10 microgram nasal spray (ARTG 59320, 21 April 1997), 100 and 200 microgram tablets (ARTG 93678 and 93731, both 2 April 2003), and 60, 120 and 240 microgram sublingual wafers (ARTG 121720, 121721 and 121722, all 28 June 2007).