Stop nifedipine if ischaemic chest pain occurs or existing pain increases after starting treatment.
Do not combine with magnesium sulphate, salbutamol IV, and other calcium channel blockers.
Monitor combination with cimetidine (enhances hypotensive effects), phenytoin (risk of phenytoin overdose), rifampicin (efficacy of nifedipine diminished), itraconazole (increased risk of oedema), beta-blockers (increased adverse cardiac effects).
Pregnancy: CONTRA-INDICATED during the first trimester. Never administer sublingually (risk of foetal death from placental hypoperfusion).
Breast-feeding: avoid
Remarks
Nifedipine is a calcium channel blocker that is also used in the management of hypertension at doses of 10 to 40 mg 2 times daily or 20 to 90 mg once daily, depending on the sustained-release form used.