Nifedipine

I. Vasospastic Angina Nifedipine extended-release tablets are indicated for the management of vasospastic angina confirmed by any of the following criteria: 1) classical pattern of angina at rest accompanied by ST segment elevation, 2) angina or coronary artery spasm provoked by ergonovine, or 3) angiographically demonstrated coronary artery spasm. In those patients who have had angiography, the presence of significant fixed obstructive disease is not incompatible with the diagnosis of vasospastic angina, provided that the above criteria are satisfied. …

• Dosage must be adjusted according to each patient’s needs
• Therapy for either hypertension or angina should be initiated with 30 or 60 mg once daily
• Nifedipine Extended-Release Tablets USP should be swallowed whole and should not be bitten or divided
• In general, titration should proceed over a 7 to 14 day period so that the physician can fully assess the response to each dose level and monitor blood pressure before proceeding to higher doses
• Since steady-state plasma levels are achieved on the second day of dosing, titration may proceed more rapidly, if symptoms so warrant, provided the patient is assessed frequently
• Titration to doses above 120 mg are not recommended
• Angina patients controlled on nifedipine capsules alone or in combination with other antianginal medications may be safely switched to nifedipine extended-release tablets at the nearest equivalent total daily dose (e.g., 30 mg t.i.d. of nifedipine capsules may be changed to 90 mg once daily of nifedipine extended-release tablets)
• Subsequent titration to higher or lower doses may be necessary and should be initiated as clinically warranted
• Experience with doses greater than 90 mg in patients with angina is limited
• Therefore, doses greater than 90 mg should be used with caution and only when clinically warranted
• Avoid coadministration of nifedipine with grapefruit juice (see CLINICAL PHARMACOLOGY and PRECAUTIONS: Other Interactions )
• No “rebound effect” has been observed upon discontinuation of nifedipine extended-release tablets. …

Known hypersensitivity reaction to nifedipine.

Excessive Hypotension Although in most angina patients the hypotensive effect of nifedipine is modest and well tolerated, occasional patients have had excessive and poorly tolerated hypotension. These responses have usually occurred during initial titration or at the time of subsequent upward dosage adjustment, and may be more likely in patients on concomitant beta blockers. Severe hypotension and/or increased fluid volume requirements have been reported in patients receiving nifedipine together with a beta-blocking agent who underwent coronary artery bypass surgery using high dose fentanyl anesthesia. …

ADVERSE EXPERIENCES Over 1000 patients from both controlled and open trials with nifedipine extended-release tablets in hypertension and angina were included in the evaluation of adverse experiences. All side effects reported during nifedipine extended-release tablets therapy were tabulated independent of their causal relation to medication. The most common side effect reported with nifedipine extended-release tablets was edema which was dose related and ranged in frequency from approximately 10% to about 30% at the highest dose studied (180 mg). …

Experience with nifedipine overdosage is limited. Generally, overdosage with nifedipine leading to pronounced hypotension calls for active cardiovascular support, including monitoring of cardiovascular and respiratory function, elevation of extremities, judicious use of calcium infusion, pressor agents, and fluids. Clearance of nifedipine would be expected to be prolonged in patients with impaired liver function. Since nifedipine is highly protein-bound, dialysis is not likely to be of any benefit. …

Take it when you remember, unless it is nearly time for the next dose. Then skip the missed one. Never take two doses at once to make up for it. Check your leaflet, as some medicines are different.