Nifedipine

Nifedipineis indicated for the management of vasospastic心绞痛confirmed by any of the following criteria: 1) classical pattern of angina at rest accompanied by ST segment elevation, 2) angina orcoronary artery spasmprovoked by ergonovine, or 3) angiographically demonstrated coronary artery spasm. In those patients who have hadangiography, the presence of significant fixed obstructive disease is not incompatible with the diagnosis of vasospastic angina, provided that the above criteria are satisfied. Nifedipine may also be used where the clinical presentation suggests a possible vasospastic component but where vasospasm has not been confirmed, e.g., where pain has a variable threshold on exertion or when angina is耐火材料to nitrates and/or adequate doses ofbeta blockers.

Nifedipine is indicated for the management of chronic stable angina (effort-associated angina) without evidence of vasospasm in patients who remain symptomatic despite adequate doses of beta blockers and/or organic nitrates or who cannot tolerate those agents. In chronic stable angina (effort-associated angina) nifedipine has been effective in controlled trials of up to eight weeks duration in reducing angina frequency and increasing exercise tolerance, but confirmation of sustained effectiveness and evaluation of long-term safety in these patients are incomplete. Controlled studies in small numbers of patients suggest concomitant use of nifedipine and beta-blocking agents may be beneficial in patients with chronic stable angina, but available information is not sufficient to predict with confidence the effects of concurrent treatment, especially in patients with compromised leftventricularfunction or cardiac conduction abnormalities. When introducing such concomitant therapy, care must be taken to monitor blood pressure closely since severehypotensioncan occur from the combined effects of the drugs.

Nifedipine is available under the following different brand names:Procardia,Procardia XL,AdalatCC, Nifedical XL, Adalat,Afeditab CR, and Nifediac CC.

Dosage Forms and Strengths

Capsule

• 10 mg
• 20 mg

Tablet, extended release

• 30 mg
• 60 mg
• 90 mg

Dosage Considerations – Should be Given as Follows:

Not FDA approved for children

Potential toxic dose in children under 6 years: 2 mg/kg

Angina

• 10 mg (conventional) orally every 8 hours or 30-60 mg (extended release) orally once daily initially; may be increased every 7-14 days as needed
• Maintenance: 10-20 mg (conventional) orally every 8 hours up to 20-30 mg orally every 6-8 hours; not to exceed 180 mg/day (conventional) or 120 mg/day (extended release)

Hypertension

• 30-60 mg (extended release) orally once daily; may be increased every 7-14 days as needed; not to exceed 90 mg/day (Adalat CC) or 120 mg/day (Procardia XL)

Hypertension, Pediatric (Off-label)

• 0.25-0.5 mg/kg/day (extended release) orally in 1 or 2 daily doses initially; not to exceed 3 mg/kg/day (120 mg/day)

Pulmonary Hypertension

• 每12小时30毫克(延长释放)口服;妈y be increased to 120-240 mg/day (monitor)

Raynaud Phenomenon (Off-label)

• 30-120 mg (extended release) orally once daily

Anal Fissures (Off-label)

• 0.2% topical gel/ointment(extemporaneously compounded) every 12 hours for 3-6 weeks
• 20 mgsublingual

Dosing Modifications

• Peritoneal dialysis(PD) or hemodialysis (HD): Supplemental dose not necessary
• Cirrhosis: Consider dose adjustment
• Geriatric: Avoid conventional (i.e., immediate-release) product; potential for hypotension and risk of precipitating myocardialischemia

Administration

• Take on empty stomach

Common side effects of nifedipine include:

• Swelling of extremities
• Dizziness
• Flushing
• Headache
• Heartburn
• Nausea
• Muscle cramps
• Mood change
• Nervousness
• Cough
• Indigestion
• Palpitations
• Wheezing
• Low blood pressure (hypotension), transient
• Hives
• Itching
• Constipation
• Chest pain

Other side effects of nifedipine include:

• Swollen gums
• Agranulocytosis
• Erectile dysfunction

Postmarketing side effects of nifedipine reported include:

• Exfoliative orbullousskin adverse events (e.g.,erythema multiforme,Stevens-Johnson syndrome, toxicepidermalnecrolysis)
• Photosensitivityreactions
• Acute generalized exanthematouspustulosis

This is not a complete list of side effects and other serious side effects may occur. Call your doctor for information and medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

If your doctor has directed you to use this medication for your condition, your doctor or pharmacist may already be aware of any possible drug interactions or side effects and may be monitoring you for them. Do not start, stop, or change the dosage of this medicine or any medicine before getting further information from your doctor, healthcare provider or pharmacist first.

• Severe interactions of nifedipine include:
  • None
• Nifedipine has serious interactions with at least 30 different drugs.
• Nifedipine has moderate interactions with at least 219 different drugs.
• Nifedipine has mild interactions with at least 132 different drugs.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

Warnings

This medication contains nifedipine. Do not take Procardia, Procardia XL, Adalat CC, Nifedical XL, Adalat, Afeditab CR, or Nifediac CC if you are allergic to nifedipine or any ingredients contained in this drug.

This medication contains nifedipine. Do not takeProAmatineor Orvaten if you are allergic to nifedipine or any ingredients contained in this drug.

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.

Contraindications

• Hypersensitivity to nifedipine or other calcium-channel blockers
• Cardiogenic shock
• Concomitant administration with strong CYP3A4 inducers (e.g.,rifampin, rifabutin,phenobarbital,苯妥英,carbamazepine, St John's wort) significantly reduces nifedipine efficacy
• Immediate release preparation (sublingually or orally) for urgent or emergent hypertension

Effects of Drug Abuse

No information available

Short-Term Effects

• See "What Are Side Effects Associated with Using Nifedipine?"

Long-Term Effects

• See "What Are Side Effects Associated with Using Nifedipine?"

Cautions

• Use with caution in (up to 4 weeks)myocardial infarction(MI), congestive heart failure (CHF), advancedaortic stenosis, peripheral edema, symptomatic hypotension, unstable angina, concurrent use of beta blockers, hepatic or renal impairment, persistent progressivedermatologicreactions, exacerbation of angina (during initiation of treatment, after a dose increase, or after withdrawal ofbeta blocker).
• Short-acting nifedipine may be less safe than other calcium-channel blockers in management of angina, hypertension, or acute MI.
• Use cautiously in combination with quinidine.
• Conventional (short-acting) form not indicated for hypertension.
• Use extended-release form with caution in severeGIstenosis; rare reports of GI obstructive symptoms in patients with known strictures or without history of GI obstruction in association with ingestion of long-acting nifedipine; bezoars can occur in very rare cases and may necessitate surgical intervention.
• Extended-release form contains lactose; thus, patients with rare hereditary problems ofgalactoseintolerance, Lapplactase deficiency, or glucose-galactose妈labsorptionshould not take this medicine.
• Cirrhosis: Clearance reduced and systemic exposure increased.
• CYP3A inhibitors (e.g.,ketoconazole,fluconazole,itraconazoleclarithromycin,erythromycin,grapefruit, nefazodone, saquinavir, indinavir, nelfinavir, ritonavir) may inhibit nifedipinemetabolismand result in increased exposure when co-administered.
• Strong CYP3A inducers (e.g., rifampin, rifabutin, phenobarbital, phenytoin, carbamazepine, and St John's wort) may enhance nifedipine metabolism and result in decreased exposure when co-administered.
• Avoid use in heart failure due to lack of benefit, and/or worse outcomes withcalcium channel blockersin general.
• Use with caution in patients withhypertrophiccardiomyopathy and outflow tract obstruction; reduction in afterload may worsen symptoms associated with this condition.
• Avoid use of immediate release formulation in the elderly; may cause hypotension and risk precipitating myocardial ischemia.

Pregnancy and Lactation

• Use nifedipine with caution during pregnancy if benefits outweigh risks. Animal studies show risk and human studies are not available, or neither animal nor human studies were done.
• Nifedipine is distributed into breast milk; the manufacturer suggests discontinuing the drug or refraining from nursing (however, theAmerican Academy of Pediatricsstates that the drug is safe for nursing).