Nifedipine

FDA Drug Information • Also known as: Nifedipine, Nifedipine Er, Procardia Xl

Brand Names: Nifedipine, Nifedipine Er, Procardia Xl
Dosage Form: POWDER
Product Type: BULK INGREDIENT

Description

DESCRIPTION Nifedipine is a drug belonging to a class of pharmacological agents known as the calcium channel blockers. Nifedipine is 3,5-pyridinedicarboxylic acid, 1,4-dihydro-2,6-dimethyl-4-(2-nitrophenyl)-, dimethyl ester, C 17 H 18 N 2 O 6 , and has the structural formula: Nifedipine is a yellow crystalline substance, practically insoluble in water but soluble in ethanol. It has a molecular weight of 346.3. Nifedipine GITS (Gastrointestinal Therapeutic System) tablet is formulated as a once-a-day controlled-release tablet for oral administration designed to deliver 30, 60, or 90 mg of nifedipine. Inert ingredients in the formulations are: cellulose acetate; ferric oxide; hypromellose; magnesium stearate; polyethylene glycol; polyethylene oxide; potassium chloride; povidone; sodium chloride; titanium dioxide; propylene glycol and black iron oxide. The USP Dissolution Test is pending. image description System Components and Performance Nifedipine extended-release tablets are similar in appearance to a conventional tablet. It consists, however, of a semipermeable membrane surrounding an osmotically active drug core. The core itself is divided into two layers: an “active” layer containing the drug, and a “push” layer containing pharmacologically inert (but osmotically active) components. As water from the gastrointestinal tract enters the tablet, pressure increases in the osmotic layer and “pushes” against the drug layer, releasing drug through the precision laser-drilled tablet orifice in the active layer. Nifedipine extended-release tablets are designed to provide nifedipine at an approximately constant rate over 24 hours. This controlled rate of drug delivery into the gastrointestinal lumen is independent of pH or gastrointestinal motility. Nifedipine extended-release tablets depend for its action on the existence of an osmotic gradient between the contents of the bi-layer core and fluid in the gastrointestinal tract. Drug delivery is essentially constant as long...

What Is Nifedipine Used For?

INDICATIONS & USAGE 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. Nifedipine extended-release tablets 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 in unstable angina where electrocardiographic findings are compatible with intermittent vasospasm, or when angina is refractory to nitrates and/or adequate doses of beta blockers. II. Chronic Stable Angina (Classical Effort-Associated Angina) Nifedipine extended-release tablets are 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 is 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 left ventricular function or cardiac conduction abnormalities. When introducing such concomitant therapy, care must be taken to monitor blood pressure closely, since severe hypotension can occur from the combined effects of the drugs. (See WARNINGS ) III. Hypertension Nifedipine extended-release tablets are indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including nifedipine extended-release tablets. Control of high blood pressure should be part of comprehensive cardiovascular risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. Many patients will require more than one drug to achieve blood pressure goals. For specific advice on goals and...

Dosage and Administration

DOSAGE & ADMINISTRATION 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. However, if discontinuation of nifedipine is necessary, sound clinical practice suggests that the dosage should be decreased gradually with close physician supervision. Care should be taken when dispensing nifedipine extended-release tablets to assure that the extended release dosage form has been prescribed. Coadministration with Other Antianginal Drugs Sublingual nitroglycerin may be taken as required for the control of acute manifestations of angina, particularly during nifedipine titration. See PRECAUTIONS, Drug Interactions , for information on coadministration of nifedipine with beta blockers or long-acting nitrates.

Side Effects (Adverse Reactions)

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). Other common adverse experiences reported in placebo-controlled trials include: Nifedipine Extended-Release Tablets (%) (N=707) Placebo (%) (N=266) Adverse Effect Headache 15.8 9.8 Fatigue 5.9 4.1 Dizziness 4.1 4.5 Constipation 3.3 2.3 Nausea 3.3 1.9 Of these, only edema and headache were more common in nifedipine extended-release tablets patients than placebo patients. The following adverse reactions occurred with an incidence of less than 3.0%. With the exception of leg cramps, the incidence of these side effects was similar to that of placebo alone. Body as a Whole/Systemic: asthenia, flushing, pain Cardiovascular: palpitations Central Nervous System: insomnia, nervousness, paresthesia, somnolence Dermatologic: pruritus, rash Gastrointestinal: abdominal pain, diarrhea, dry mouth, dyspepsia, flatulence Musculoskeletal: arthralgia, leg cramps Respiratory: chest pain (nonspecific), dyspnea Urogenital: impotence, polyuria Other adverse reactions were reported sporadically with an incidence of 1.0% or less. These include: Body as a Whole/Systemic: face edema, fever, hot flashes, malaise, periorbital edema, rigors Cardiovascular: arrhythmia, hypotension, increased angina, tachycardia, syncope Central Nervous System: anxiety, ataxia, decreased libido, depression, hypertonia, hypoesthesia, migraine, paroniria, tremor, vertigo Dermatologic: alopecia, increased sweating, urticaria, purpura Gastrointestinal: eructation, gastroesophageal reflux, gum hyperplasia, melena, vomiting, weight increase Musculoskeletal: back pain, gout, myalgias Respiratory: coughing, epistaxis, upper respiratory tract infection, respiratory disorder, sinusitis Special Senses: abnormal lacrimation, abnormal vision, taste perversion, tinnitus Urogenital/Reproductive: breast pain, dysuria, hematuria, nocturia Adverse experiences which occurred in less than 1 in 1000 patients cannot be distinguished from concurrent disease states or medications. The following adverse experiences, reported in less than 1% of patients, occurred under conditions (e.g., open trials, marketing experience) where a causal relationship is uncertain: gastrointestinal irritation, gastrointestinal bleeding, gynecomastia. Gastrointestinal obstruction resulting in hospitalization and surgery, including the need for bezoar removal, has occurred in association with nifedipine extended-release tablets, even in patients with no prior history of gastrointestinal disease. (See WARNINGS ) Cases of tablet adherence to the gastrointestinal wall with ulceration have been reported, some requiring hospitalization and intervention. In multiple-dose U.S. and foreign controlled studies with nifedipine capsules in which adverse reactions were reported spontaneously, adverse effects were frequent but generally not serious and rarely required discontinuation of therapy or dosage adjustment. Most were expected consequences of the vasodilator effects of nifedipine. Adverse Effect Nifedipine Capsules (%) (N=226) Placebo (%) (N=235) Dizziness, lightheadedness, giddiness 27 15 Flushing, heat sensation 25 8 Headache 23 20 Weakness 12 10 Nausea, heartburn 11 8 Muscle cramps, tremor 8 3 Peripheral edema 7 1 Nervousness, mood changes 7 4 Palpitations 7 5 Dyspnea, cough, wheezing 6 3 Nasal congestion, sore throat 6 8 There is also a large uncontrolled experience in over 2100 patients in the United States. Most of the patients had vasospastic or resistant angina pectoris, and...

Warnings and Precautions

WARNINGS 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. The interaction with high dose fentanyl appears to be due to the combination of nifedipine and a beta blocker, but the possibility that it may occur with nifedipine alone, with low doses of fentanyl, in other surgical procedures, or with other narcotic analgesics cannot be ruled out. In nifedipine-treated patients where surgery using high dose fentanyl anesthesia is contemplated, the physician should be aware of these potential problems and, if the patient’s condition permits, sufficient time (at least 36 hours) should be allowed for nifedipine to be washed out of the body prior to surgery. The following information should be taken into account in those patients who are being treated for hypertension as well as angina: Increased Angina and/or Myocardial Infarction Rarely, patients, particularly those who have severe obstructive coronary artery disease, have developed well documented increased frequency, duration and/or severity of angina or acute myocardial infarction on starting nifedipine or at the time of dosage increase. The mechanism of this effect is not established. Beta Blocker Withdrawal It is important to taper beta blockers if possible, rather than stopping them abruptly before beginning nifedipine. Patients recently withdrawn from beta blockers may develop a withdrawal syndrome with increased angina, probably related to increased sensitivity to catecholamines. Initiation of nifedipine treatment will not prevent this occurrence and on occasion has been reported to increase it. Congestive Heart Failure Rarely, patients, usually receiving a beta blocker, have developed heart failure after beginning nifedipine. Patients with tight aortic stenosis may be at greater risk for such an event, as the unloading effect of nifedipine would be expected to be of less benefit, owing to the fixed impedance to flow across the aortic valve in these patients. Gastrointestinal Obstruction Requiring Surgery There have been rare reports of obstructive symptoms in patients with known strictures in association with the ingestion of nifedipine extended-release tablets. Bezoars can occur in very rare cases and may require surgical intervention. Cases of serious gastrointestinal obstruction have been identified in patients with no known gastrointestinal disease, including the need for hospitalization and surgical intervention. Risk factors for a...

Contraindications

CONTRAINDICATIONS Known hypersensitivity reaction to nifedipine.

Overdosage

OVERDOSAGE 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. There has been one reported case of massive overdosage with nifedipine extended-release tablets. The main effects of ingestion of approximately 4800 mg of nifedipine extended-release tablets in a young man attempting suicide as a result of cocaine-induced depression was initial dizziness, palpitations, flushing, and nervousness. Within several hours of ingestion, nausea, vomiting, and generalized edema developed. No significant hypotension was apparent at presentation, 18 hours post-ingestion. Electrolyte abnormalities consisted of a mild, transient elevation of serum creatinine, and modest elevations of LDH and CPK, but normal SGOT. Vital signs remained stable, no electrocardiographic abnormalities were noted, and renal function returned to normal within 24 to 48 hours with routine supportive measures alone. No prolonged sequelae were observed. The effect of a single 900 mg ingestion of nifedipine capsules in a depressed anginal patient also on tricyclic antidepressants was loss of consciousness within 30 minutes of ingestion, and profound hypotension, which responded to calcium infusion, pressor agents, and fluid replacement. A variety of ECG abnormalities were seen in this patient with a history of bundle branch block, including sinus bradycardia and varying degrees of AV block. These dictated the prophylactic placement of a temporary ventricular pacemaker, but otherwise resolved spontaneously. Significant hyperglycemia was seen initially in this patient,...

How Supplied

HOW SUPPLIED Nifedipine Extended-Release Tablets USP are supplied as 30 mg round, biconvex, rose-pink, film-coated tablets with “T011” in black ink on one side and plain on the other side: Bottles of 100: (NDC 24979-011-01) Bottles of 300: (NDC 24979-011-12) Nifedipine extended-release tablets USP are supplied as 60 mg round, biconvex, rose-pink, film-coated tablets with “T010” in black ink on one side and plain on the other side: Bottles of 100: (NDC 24979-010-01) Bottles of 300: (NDC 24979-010-12) Nifedipine extended-release tablets USP are supplied as 90 mg round, biconvex, rose-pink, film-coated tablets with “T009” in black ink on one side and plain on the other side: Bottles of 100: (NDC 24979-009-01) Bottles of 300: (NDC 24979-009-12) Store at 20° to 25°C (68° to 77°F). [see USP Controlled Room Temperature] Protect from moisture and humidity. Manufactured for: TWi Pharmaceuticals USA, Inc. Paramus, NJ 07652 Manufactured by: China Chemical & Pharmaceutical Co., Ltd. Tainan City, 72042, Taiwan OS011 01/2017

About This Information

This drug information is sourced from FDA-approved labeling via the openFDA database. It is intended for educational and reference purposes only. This is not medical advice. Always consult your healthcare provider before making decisions about medication. Drug information may be updated by the FDA; check with your pharmacist for the most current information.

What are side effects?

Side effects are unwanted reactions that can occur when taking a medication. They range from mild (headache, nausea) to severe (allergic reactions, organ damage). Not everyone experiences side effects, and severity varies. Report any concerning side effects to your doctor.

What are drug interactions?

Drug interactions occur when a medication is affected by another drug, food, or supplement. Interactions can make medications less effective or cause dangerous side effects. Always tell your doctor about all medications and supplements you take.