Nifedipine
Brand Names: Procardia, Nifedical XL, Adalat CC
Generic Available
Common Dosage Forms:
Capsules: 10 mg, 20 mg
Tablets, sustained release: 30 mg, 60 mg, 90 mg
FDA Indications/Dosages:
For the treatment of vasospastic angina and chronic stable angina: Start with 10 mg three times a day.
Maintenance (capsules): 30-120 mg per day in three to four divided doses.
Maintenance (tablets): 30-90 mg once daily. Patients maintained on capsule formulation may be switched to the sustained release formulation at the nearest equivalent total daily dose.
For the treatment of hypertension: One sustained release tablet daily.
Monitor: BP
Pharmacology/Pharmacokinetics: Nifedipine is a calcium channel blocker which inhibits the movement (influx) of calcium ions across specific cellular membranes (slow channels) resulting in: (1) dilation of coronary arteries and arterioles; (2) coronary spasm inhibition; (3) dilation of peripheral arterioles which lowers peripheral resistance. Peak plasma levels after ingestion of the capsule formulation occurs in 30 minutes. Half-life equals 2 hours. Nifedipine is metabolized in the liver and excreted in the urine as inactive metabolites. Nifedipine is highly bound to plasma proteins.
Drug Interactions: Cimetidine or grapefruit juice may decrease hepatic metabolism of nifedipine. Increased nifedipine toxicity when used with quinidine.
Contraindications/Precautions: Use with caution in patients undergoing surgery where fentanyl is used, in patients recently discontinuing b-adrenergic blocker therapy, and in patients with tight aortic stenosis, hepatic impairment, or congestive heart failure. May cause rare increase in angina or myocardial infarction on starting therapy on starting therapy or increasing dose. Pregnancy Category C.
Adverse Effects: Peripheral and pulmonary edema, palpitations, hypotension, dizziness, giddiness, headache, weakness, rash, nausea, flushing, nasal congestion, dyspnea, cramps, and cough.
Patient Consultation:
Do not discontinue therapy without first consulting a physician.
Take each dose on an empty stomach (one hour before or two hours after a meal) unless otherwise directed by a physician.
Caution: May cause fainting with sudden changes in posture.
Do not chew or divide long-acting tablets.
Contact a physician if adverse effects become severe.
Store in a cool, dry place away from sunlight and children.
If a dose is missed, take it as soon as possible. If taken within 12 hours of the next dose, skip the next dose and return to schedule.
Do not take OTC cough and cold remedies with first checking with your physician or pharmacist.
Avoid grapefruit juice during therapy.
