nifedipine

Drug Name

Generic Name :  nifedipine

Brand Name:  Adalat, Adalat CC, Adalat XL (CAN), Apo-Nifed (CAN), Apo-Nifed AP (CAN), Nifedical XL, Novo-Nifedin (CAN), Procardia, Procardia XL

Classification: Calcium channel-blocker, Antianginal, Antihypertensive

Pregnancy Category C

Dosage & Route

Available forms : ER tablets—30, 60, 90 mg; capsules—10, 20 mg

ADULTS
  • Initial dose, 10 mg tid PO. Maintenance range, 10–20 mg tid. Higher doses (20–30 mg tid–qid) may be required, depending on patient response. Adjust over 7–14 days. More than 180 mg/day is not recommended.
Sustained-release
  • 30–60 mg PO once daily. Adjust over 7–14 days. Usual maximum dose is 90–120 mg/day.
Therapeutic actions
  • Nifedipine blocks the slow calcium channels thus preventing the flow of calcium ions into the cell. It produces peripheral and coronary vasodilatation, reduces afterload, peripheral resistance and BP, increases coronary blood flow and causes reflex tachycardia. It has little or no effect on cardiac conduction and rarely has negative inotropic activity.
Indications
  • Angina pectoris due to coronary artery spasm (Prinzmetal’s variant angina)
  • Chronic stable angina (effort-associated angina)
  • SR preparation only: Treatment of hypertension
  • Orphan drug use: Treatment of interstitial cystitis
Adverse effects
  • Peripheral edema, hypotension, palpitations, tachycardia, flushing, dizziness, headache, nausea, increased micturition frequency, lethargy, eye pain, mental depression, visual disturbances, gingival hyperplasia, myalgia, tremor, impotence, fever, paradoxical increase in ischemic chest pain during initiation of treatment, rashes, abnormalities in liver function (including cholestasis), GI obstruction in some tablets covered in indigestable membrane.
Contraindications
  • Acute MI, cardiogenic shock, acute unstable angina, treatment of anginal attack in chronic stable angina.
Nursing considerations
Assessment
  • History: Allergy to nifedipine; pregnancy; lactation
  • Physical: Skin lesions, color, edema; orientation, reflexes; P, BP, baseline ECG, peripheral perfusion, auscultation; R, adventitious sounds; liver evaluation, normal GI output; LFTs
Interventions
  • WARNING: Monitor patient carefully (BP, cardiac rhythm, and output) while drug is being adjusted to therapeutic dose; the dosage may be increased more rapidly in hospitalized patients under close supervision. Do not exceed 30 mg/dose increases.
  • Ensure that patients do not chew or divide sustained-release tablets.
  • Taper dosage of beta-blockers before nifedipine therapy.
  • Protect drug from light and moisture.
Teaching points
  • Do not chew, cut, or crush sustained-release tablets. Swallow whole.
  • You may experience these side effects: Nausea, vomiting (eat frequent small meals); dizziness, light-headedness, vertigo (avoid driving and operating dangerous machinery; take special precautions to avoid falling); muscle cramps, joint stiffness, sweating, sexual difficulties (reversible).
  • Report irregular heartbeat, shortness of breath, swelling of the hands or feet, pronounced dizziness, constipation.