APO-NIFEDIPINE XR

What it is

APO-NIFEDIPINE XR contains nifedipine in controlled release tablet formulations of 30 mg and 60 mg strength. Nifedipine inhibits the transmembrane influx of calcium ions into cardiac and vascular smooth muscle by selectively inhibiting calcium movement through the slow channel, which reduces free calcium available within muscle cells and inhibits the contractile process.

Approved indications

— Treatment of hypertension. — Prophylaxis of chronic stable angina pectoris.

Dosing overview

Titration should generally proceed over a 7 to 14 day period to allow full assessment of response at each dose level. Tablets should be swallowed whole without chewing or being broken up, with a little liquid, independently of mealtimes. Grapefruit juice should be avoided.

Key safety warnings

Rare cases of increased frequency, duration and severity of angina or acute myocardial infarction have been reported when starting nifedipine or at the time of dosage increase, mainly in patients with severe obstructive coronary artery disease. APO-NIFEDIPINE XR is not suitable for acute treatment of angina pectoris due to delayed absorption from the modified release dosage formulation. Caution should be exercised in patients with hypotension as there is a risk of further reduction in blood pressure, and care must be exercised in patients with very low blood pressure (severe hypotension with systolic blood pressure less than 90 mm Hg). Mild to moderate peripheral oedema occurs in a dose dependent manner, ranging from approximately 10% with the 30 mg daily dose to about 33% at 120 mg daily, and is due to arteriolar vasodilatation rather than heart failure. Heart failure has occasionally been observed during clinical use, and care should be observed with patients whose cardiac reserve is poor or who are receiving large doses of beta-blockers. When nifedipine is administered simultaneously with beta-blockers, patients should be carefully monitored as deterioration of heart failure may develop, and nifedipine extended release tablets have no inherent antiarrhythmic action and therefore give no protection against arrhythmias from abrupt beta-blocker withdrawal, which should be achieved gradually over several days.

Contraindications

Known hypersensitivity to nifedipine, related dihydropyridine calcium channel blockers, or to any of the excipients. Pregnancy and lactation. Patients with cardiogenic shock, unstable angina, clinically significant aortic stenosis, and during or within a month of a myocardial infarction. Patients with severe hypotension. History of gastrointestinal obstruction, oesophageal obstruction, or any degree of reduced intestinal lumen diameter, and must not be used in patients with a Kock pouch, inflammatory bowel disease or Crohn's disease. Concomitant administration with rifampicin.

PBS listing

The 60 mg controlled release tablet is listed on the PBS with 2 items at an ex-manufacturer price of A$8.05, with both unrestricted and restricted access. The 30 mg controlled release tablet is listed on the PBS with 2 items at an ex-manufacturer price of A$6.41, with both restricted and unrestricted access.

Regulatory history

APO-NIFEDIPINE XR 30 mg and 60 mg controlled release tablet formulations were first listed on the ARTG on 21 October 2008.