CATAPRES

What it is

CATAPRES is clonidine hydrochloride 150 microgram per 1 mL solution for injection supplied in 1 mL ampoules. The solution is clear and colourless.

Approved indications

— Acute hypertensive crisis. — Alternative to oral therapy where the oral route of administration is inappropriate.

Dosing overview

The dose is one to two ampoules (150–300 micrograms) by intramuscular injection undiluted, or given intravenously in 10 mL of normal saline over five minutes. The dose may be repeated at intervals of 3 to 6 hours as necessary. Subcutaneous or intramuscular injection should only be administered to patients in a lying position. In patients with hepatic or renal impairment, any dose reduction required should be assessed on an individual basis. CATAPRES may be given in combination with guanethidine, alpha methyldopa or other antihypertensives to provide effective control of blood pressure in refractory cases, allowing reduction of individual drug doses and minimisation of side effects.

Key safety warnings

Special care should be exercised in treating patients with a history of depression or advanced cerebrovascular disease, as reduction of blood pressure in the latter circumstances may itself cause mental changes. Concurrent administration of tricyclic antidepressants may require adjustment of CATAPRES dosage. Termination of therapy should be gradual over more than 7 days, as sudden cessation of antihypertensive therapy is known to be associated in some instances with rebound hypertension, which may be severe, particularly in patients receiving more than the maximum recommended dose of 900 micrograms per day; following sudden discontinuation after prolonged treatment with high doses, restlessness, palpitations, rapid rise in blood pressure, nervousness, tremor, headache or nausea have been reported. Although a transient rise in blood sugar has been noted occasionally in humans treated with CATAPRES, which may be due to a pharmacologic alpha-adrenomimetic effect, no case of induced diabetes mellitus due to CATAPRES has been reported; however, patients with clinical diabetes mellitus should be watched for a possible increase in their requirements of anti-diabetic therapy. Patients who wear contact lenses should be warned that treatment with CATAPRES may cause decreased lacrimation.

Contraindications

CATAPRES should not be used in patients with known hypersensitivity to clonidine hydrochloride, and in patients with severe bradyarrhythmia resulting from either sick sinus syndrome or AV block of second or third degree.

PBS listing

CATAPRES 150 microgram tablet is listed on the PBS as an unrestricted and restricted item with an ex-manufacturer price of A$17.21.

Regulatory history

CATAPRES clonidine hydrochloride 150 microgram per 1 mL injection ampoule was first listed on the ARTG on 26 September 1991.