DBL

What it is

DBL Dexamethasone Sodium Phosphate Injection is a solution for injection containing dexamethasone sodium phosphate equivalent to 4 mg of dexamethasone phosphate per millilitre. Dexamethasone is a synthetic adrenocorticosteroid with glucocorticoid activity, being about 25 to 30 times as potent as hydrocortisone. Unlike hydrocortisone, dexamethasone has little if any mineralocorticoid activity and has anti-inflammatory and immunosuppressant activity.

Approved indications

— Acute adrenocortical insufficiency including Addison's disease and bilateral adrenalectomy. — Relative adrenocortical insufficiency arising from prolonged administration of adrenocortical steroids, where steroid therapy should be reinstituted during stress such as surgery, trauma, burns or severe infections. — Systemic lupus erythematosus, polyarteritis nodosa, dermatomyositis, giant cell arteritis, and acute rheumatic carditis. — Status asthmaticus, chronic asthma, sarcoidosis and respiratory insufficiency. — Leukaemia, idiopathic thrombocytopaenic purpura in adults, and acquired autoimmune haemolytic anaemia. — Rheumatoid arthritis and osteoarthritis. — Psoriasis, erythema multiforme, pemphigus, and other skin diseases. — Ulcerative colitis and regional enteritis. — Cerebral oedema associated with brain tumours, neurosurgery or stroke, and oedema associated with acute non-infectious laryngospasm. — Allergic conjunctivitis, keratitis, allergic corneal marginal ulcers, chorioretinitis, optic neuritis and anterior ischaemic optic neuropathy. — Hypercalcaemia associated with cancer, and leukaemias and lymphomas in adults and acute leukaemia in children. — Preoperative and postoperative support in surgical procedures when adrenocortical reserve is doubtful, including treatment of shock due to excessive blood loss during surgery. — Shock as an adjunct to treatment.

Dosing overview

Dosage requirements are variable and must be individualised on the basis of the disease being treated and patient response, with intravenous or intramuscular dosage usually ranging from 0.5 to 24 mg of dexamethasone phosphate daily. The duration of therapy is dependent on clinical response and should be adjusted to the minimum required to maintain desired clinical response, with gradual withdrawal on completion of therapy. For shock of haemorrhagic, traumatic or surgical origin, the usual dose is 2 to 6 mg/kg bodyweight as a single intravenous injection, which may be repeated in 2 to 6 hours if shock persists. For cerebral oedema, an initial dose of 10 mg intravenously followed by 4 mg intramuscularly every 6 hours is given until symptoms subside (usually 12 to 24 hours), then reduced over 5 to 7 days.

Key safety warnings

Tumour lysis syndrome has been reported in patients with haematological malignancies following the use of dexamethasone alone or in combination with chemotherapeutic agents, and patients at high risk should be monitored closely. Dexamethasone formulations containing sulfites should not be used for intrathecal therapy due to potential risk of neurotoxicity. The excipient sodium sulfite may rarely cause severe hypersensitivity reactions and bronchospasm. Long-term treatment should not be abruptly discontinued as too rapid withdrawal may lead to drug-induced secondary adrenocortical insufficiency, which may persist for months after therapy is discontinued; in situations of stress during this period, corticosteroid doses may need to be increased or therapy reinstituted. Severe anaphylactoid reactions have occurred after administration of parenteral corticosteroids, including glottis oedema, urticaria and bronchospasm particularly in patients with allergy history, and appropriate precautions should be taken prior to administration. Potentially severe psychiatric reactions may occur, typically emerging within days or weeks of starting treatment; most reactions recover after dose reduction or withdrawal, although specific treatment may be necessary, and patients should seek medical advice if worrying psychological symptoms develop.

Contraindications

Administration of dexamethasone is contraindicated in systemic fungal infections or other systemic infections unless specific anti-infective therapy is given, hypersensitivity to dexamethasone or other corticosteroids or to any component of the injection including sulfites, administration of live virus vaccines, and in patients with myasthenia gravis, peptic ulcer, osteoporosis or psychoses. Local injection is contraindicated in patients with bacteraemia, unstable joints, or infection at the injection site such as septic arthritis.

Regulatory history

DBL Dexamethasone Sodium Phosphate Injection 4 mg/1 mL was first listed on the ARTG on 8 October 1991. The 8 mg/2 mL vial formulation was first listed on 18 March 2011.