Alpha-Nifedipine Retard - General Information
A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.
Pharmacology of Alpha-Nifedipine Retard
Alpha-Nifedipine Retard, the prototype of the dihydropyridine class of calcium-channel antagonists, is similar to other dihydropyridines including amlodipine, felodipine, isradipine, and nicardipine. Alpha-Nifedipine Retard is used to treat Prinzmetal's angina, hypertension, and other vascular disorders such as Raynaud's phenomenon. By blocking the calcium channels, Alpha-Nifedipine Retard inhibits the spasm of the coronary artery and dilates the systemic arteries, results in a increase of myocardial oxygen supply and a decrease in systemic blood pressure.
Alpha-Nifedipine Retard for patients
Nifedipine, known as a calcium channel blocker, is used to treat high blood pressure and some forms of chest pain known as angina. This medication works by relaxing blood vessels and decreasing the pressure on the heart. This can lead to dizziness, headache, lightheadedness, flushing and swelling of the legs. You should report this to your physician because it can often be easily treated with a diuretic (water-pill). This medication is available in an extended-release form allowing for once a day dosing. Some brands must be taken on an empty stomach. Other brands are made in porous capsule which slowly releases the medication. You may notice the empty capsule in your stool. Extended release medications should not be crushed, cut or split because this destroys the slow release mechanism. If you are taking this for high blood pressure, you should have your blood pressure checked regularly to make sure the medication is working.
Alpha-Nifedipine Retard Interactions
Beta-adrenergic Blocking Agents: Experience in over 1400 patients in a non-comparative clinical trial has shown that concomitant administration of nifedipine and beta-blocking agents is usually well tolerated, but there have been occasional literature reports suggesting that the combination may increase the likelihood of congestive heart failure, severe hypotension or exacerbation of angina.
Long Acting Nitrates: Nifedipine may be safely co-administered with nitrates, but there have been no controlled studies to evaluate the antianginal effectiveness of this combination.
Digitalis: Immediate Release Capsules: Since there have been isolated reports of patients with elevated digoxin levels, and there is a possible interaction between digoxin and nifedipine, it is recommended that digoxin levels be monitored when initiating, adjusting, and discontinuing nifedipine to avoid possible over- or under-digitalization. Extended Release Tablets: Administration of nifedipine with digoxin increased digoxin levels in 9 of 12 normal volunteers. The average increase was 45%. Another investigator found no increase in digoxin levels in 13 patients with coronary artery disease. In an uncontrolled study of over 200 patients with congestive heart failure during which digoxin blood levels were not measured, digitalis toxicity was not observed. Since there have been isolated reports of patients with elevated digoxin levels, it is recommended that digoxin levels be monitored when initiating, adjusting, and discontinuing nifedipine to avoid possible over- or under-digitalization.
Quinidine: Immediate Release Capsules: There have been rare reports of an interaction between quinidine and nifedipine (with a decreased plasma level of quinidine).
Coumarin Anticoagulants: There have been rare reports of increased prothrombin time in patients taking coumarin anticoagulants to whom nifedipine was administered. However, the relationship to nifedipine therapy is uncertain.
Cimetidine: A study in 6 healthy volunteers has shown a significant increase in peak nifedipine plasma levels (80%) and area-under-the-curve (74%) after a 1 week course of cimetidine at 1000 mg per day and nifedipine at 40 mg per day. Ranitidine produced smaller, non-significant increases. The effect may be mediated by the known inhibition of cimetidine on hepatic cytochrome P-450, the enzyme system probably responsible for the first-pass metabolism of nifedipine. If nifedipine therapy is initiated in a patient currently receiving cimetidine, cautious titration is advised.
Alpha-Nifedipine Retard Contraindications
Known hypersensitivity reaction to nifedipine.
Additional information about Alpha-Nifedipine Retard
Alpha-Nifedipine Retard Indication: For the management of vasospastic angina, chronic stable angina and hypertension.
Mechanism Of Action: Alpha-Nifedipine Retard inhibits the influx of extracellular calcium through myocardial and vascular membrane pores by physically plugging the channel. The decrease in intracellular calcium inhibits the contractile processes of smooth muscle cells, causing dilation of the coronary and systemic arteries, increased oxygen delivery to the myocardial tissue, decreased total peripheral resistance, decreased systemic blood pressure, and decreased afterload.
Drug Interactions: Amobarbital The barbiturate decreases the effect of the calcium channel blocker
Aprobarbital The barbiturate decreases the effect of the calcium channel blocker
Butabarbital The barbiturate decreases the effect of the calcium channel blocker
Butalbital The barbiturate decreases the effect of the calcium channel blocker
Butethal The barbiturate decreases the effect of the calcium channel blocker
Cimetidine Cimetidine increases the effect of the calcium channel blocker
Cisapride Cisapride increases the effect and toxicity of nifedipine
Cyclosporine Increased risk of gingivitis
Ginseng Ginseng increases the effect and toxicity of nifedipine
Heptabarbital The barbiturate decreases the effect of the calcium channel blocker
Hexobarbital The barbiturate decreases the effect of the calcium channel blocker
Imatinib Imatinib increases the effect and toxicity of nifedipine
Melatonin Melatonin can possibly decrease the effect of nifedipine
Methohexital The barbiturate decreases the effect of the calcium channel blocker
Methylphenobarbital The barbiturate decreases the effect of the calcium channel blocker
Pentobarbital The barbiturate decreases the effect of the calcium channel blocker
Phenobarbital The barbiturate decreases the effect of the calcium channel blocker
Primidone The barbiturate decreases the effect of the calcium channel blocker
Secobarbital The barbiturate decreases the effect of the calcium channel blocker
Talbutal The barbiturate decreases the effect of the calcium channel blocker
Rifampin Rifampin decreases the effect of the calcium channel blocker
Quinidine Decreased quinidine effect, increased nifedipine effect
Quinidine barbiturate Decreased quinidine effect, increased nifedipine effect
Dihydroquinidine barbiturate Decreased quinidine effect, increased nifedipine effect
Quinupristin Synercid increases the effect of ziprasidone
Tacrolimus Alpha-Nifedipine Retard increases serum levels of tacrolimus
St. John's Wort St. John's Wort decreases the effect of nifedipine
Food Interactions: Avoid alcohol.
Avoid taking with grapefruit juice.
Avoid natural licorice.
Take with low fat meal.
Generic Name: Nifedipine
Synonyms: Not Available
Drug Category: Tocolytic Agents; Vasodilator Agents; Calcium Channel Blockers; Dihydropyridines
Drug Type: Small Molecule; Approved
Other Brand Names containing Nifedipine: Adalat; Adalat 10; Adalat 20; Adalat 5; Adalat CC; Adalat CR; Adalat Crono; Adalat Ft; Adalat Gits; Adalat Gits 30; Adalat LA; Adalat LP; Adalat Oros; Adalat PA; Adalat Retard; Adalate; Adapine; Adapress; Alat; Aldipin; Alfadal; Alonix; Alonix S; Alpha-Nifedipine Retard; Angipec; Anifed; Anpine; Apo-Nifed; Aprical; Bonacid; Calcibloc; Calcigard; Calcilat; Camont; Cardifen; Cardilat; Cardionorm; Chronadalate; Chronadalate Lp; Citilat; Coracten; Coral; Cordafen; Cordaflex; Cordalat; Cordicant; Cordilan; Cordipin; Corinfar; Corotrend; Corynphar; Depin; Dignokonstant; Dilafed; Dilcor; Dipinkor; Duranifin; Ecodipi; Ecodipin; Ecodipin E; Fedcor; Fedcor Retard; Fenamon; Fenamon Sr; Fenihidin; Fenihidine; Glopir; Hadipin; Hexadilat; Introcar; Kordafen; Macorel; Megalat; Myogard; N1fedilat; Nedipin; Nicardia; Nifangin; Nifar; Nifdemin; Nifebene; Nifecard; Nifecor; Nifedepat; Nifedicor; Nifedin; Nifedine; Nifedipine Retard; Nifedipres; Nifedirex LP; Nifelan; Nifelat; Nifelat Q; Nifelate; Nifensar XL; Nificard; Nifidine; Nifipen; Niphedipine; Orix; Oxcord; Pidilat; Procardia; Procardia XL; Sepamit; Tibricol; Zenusin;
Absorption: Rapidly and fully absorbed following oral administration.
Toxicity (Overdose): Symptoms of overdose include dizziness, drowsiness, nausea, severe drop in blood pressure, slurred speech, and weakness. LD50=494 mg/kg (orally in mice); LD50=1022 mg/kg (orally in rats)
Protein Binding: 92-98%
Half Life: 2 hours
Dosage Forms of Alpha-Nifedipine Retard: Tablet, extended release Oral
Chemical IUPAC Name: dimethyl 2,6-dimethyl-4-(2-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate
Chemical Formula: C17H18N2O6
Nifedipine on Wikipedia: http://en.wikipedia.org/wiki/Nifedipine
Organisms Affected: Humans and other mammals