Composition
1 prolonged-release tablet contains 20 mg nifedipine.

Action
Nifedipine inhibits the influx of calcium into the myocardial cells and the smooth muscle cells of arteries. It decreases the consumption of oxygen directly by reducing heart work. The oxygen demand is also indirectly decreased as the heart is relieved.

The release of nifedipine from prolonged-release tablets is slower so nifedipine achieves the maximum concentrations in 2 to 4 hours and its effect persists for 10 to 12 hours.

Indications
The drug is intended for treatment of all kinds of high blood pressure and all kinds of angina pectoris, particularly vasospastic and chronic stable one.

Contraindications
The drug should not be used by patients hypersensitive to nifedipine or any of the other ingredients of the drug, by patients with cardiogenic shock, advanced aortic stenosis, porphyria and by nursing mothers.

Precautions
Especially at the beginning of treatment and if certain groups intended for treatment of high blood pressure (beta blockers) are taken concomitantly, blood pressure may fall substantially, which some patients tolerate poorly. In patients taking beta blockers, heart failure may occur after the introduction of nifedipine therapy. The doctor will make more frequent appointments for control examinations, which you should pass regularly, even if you feel well.

If you suffer from severe heart diseases (hypertrophic cardiomyopathy, unstable angina pectoris), diabetes, severe hepatic dysfunction or severe pulmonary hypertension and you are an elderly person, you will be closely monitored by your doctor during the introduction of nifedipine therapy.

In patients with severe coronary disease, more frequent attacks of angina pectoris may occur at the beginning of treatment. Mild to moderate peripheral edema, typically associated with arterial vasodilation and not due to left ventricular dysfunction, occurs in about one in ten patients treated with nifedipine. This edema occurs primarily in the lower extremities and usually responds to diuretic therapy.

Nifedipine can alter certain laboratory values and tests (mainly liver ones). These changes are not necessarily associated with clinical signs (although cases of cholestasis and jaundice have been reported).

Due to lack of experience in children, nifedipine prolonged-release tablets should not be used in this age group.

Pregnancy and lactation
Nifedipine should be used during pregnancy only if the potential benefit for the mother justifies the potential risk to the fetus. Nursing mothers should not use the drug.

Effects on the ability to drive and operate machinery
Especially at the beginning of treatment or with concomitant intake of alcohol, nifedipine can transiently decrease the ability to perform dangerous activities, including driving and operating machines, in susceptible patients.

Interactions
You should inform your doctor if you are taking any other drugs.

If drugs lowering high blood pressure, beta blockers, drugs increasing urine excretion and certain drugs for treating heart diseases (nitroglycerin and isosorbide with prolonged-release ) are taken concomitantly, blood pressure is additionally reduced. Fentanyl exerts similar action.

Nifedipine can seriously potentiate the toxicity of magnesium sulphate and induce neuromuscular blockade (jerky movements, swallowing difficulty, paradoxical respiration and neck muscle weakness). Therefore this combination can be hazardous and life-threatening and should be avoided.

Nifedipine may increase serum concentrations of digoxin, phenytoin (probably also carbamazepine) and tacrolimus, and potentiate their action.

Concurrent use of nifedipine and quinidine may cause decreased quinidine concentrations and increased nifedipine concentrations.

Concurrent administration of nifedipine and theophylline can alter the metabolism of theophylline. Therefore theophylline serum concentrations should be closely monitored when nifedipine is added, discontinued, or when dosing changes occur. Some adjustments of theophylline dosage may be necessary.

Concomitant administration of nifedipine and rifampicin may cause lowered serum nifedipine concentrations and attenuation of cardiovascular stability (hypertension, exacerbation of angina).

Concurrent administration of nifedipine and cimetidine. triazole antifungals (itraconazole, fluconazole), imidazole antifungals (ketoconazole), cyclosporine, ritonavir or saquinavir may cause elevated serum nifedipine concentrations, and potentiate its action.

During treatment with nifedipine it is not recommended to drink great amounts of grapefruit juice because it can elevate serum levels of nifedipine, thus increasing its effect.

Nifedipine may interfere with the interpretation of pulmonary function tests after a methacholine bronchial challenge. If possible, nifedipine should be discontinued prior to a methacholine test.

Dosage and administration
Dosage is always individualized and directed by the doctor. Tablets should not be broken or chewed.

The usual dosage is one prolonged-release tablet twice daily. If necessary, the dose may be increased to two prolonged-release tablets twice daily. In patients with Prinzmetal's angina, the daily dose may be increased to 80 mg or up to 120 mg daily.

Overdosage
Overdosage could result in excessive peripheral vasodilation with subsequent marked and probably prolonged hypotension. Hypotension is usually manifested as nausea, accelerated heartbeat, dizziness, lightheadedness or fainting. If this occurs, you should lie down, elevate the legs with a pillow and call the doctor.

If large quantities of prolonged-release tablets have been ingested, the signs of intoxication can appear only after a few hours (3 or 4 hours). The signs of intoxication are lowered blood pressure, shock, slow heartbeat or accelerated heartbeat, heart failure and convulsions. After the ingestion of a large number of tablets, the doctor should be consulted as soon as possible so that he may determine the appropriate treatment (gastric lavage, adsorption to activated charcoal and symptomatic treatment).

Undesirable effects
Side effects are transient and mild and usually do not necessitate discontinuation of treatment. The most common side effects are dizziness, lightheadedness, headache, fatigue, weakness, facial flushing, heat sensation, peripheral edema (around the ankles, feet, shanks or periorbital), tachycardia, nausea and heartburn. Rarely, transient hypotension may occur.

Less frequently, palpitation, nasal and chest congestion, shortness of breath, diarrhea, constipation, flatulence, joint stiffness, muscle cramps, shakiness, nervousness, jitteriness, sleep disturbances, blurred vision, difficulties in balance, dermatitis, pruritus, urticaria, fever, sweating, chills, sexual disorders may occur.

Syncope, thrombocytopenia, anemia, leukopenia, purpura, allergic hepatitis, gingival hyperplasia, depression, paranoid syndrome, transient blindness at the peak of plasma level, erythromelalgia and arthritis with positive ANA may also occur.

Nifedipine can alter certain laboratory values and tests (mainly liver ones). These changes are not necessarily associated with clinical signs (although cases of cholestasis and jaundice have been reported).

The patient should inform his doctor about undesirable effects, particularly about those that are not mentioned in the insert leaflet.

Storage and expiry date
The drug should not be used after the expiry date shown on the packaging.
Do not store over 25°C. Protect from light and moisture.

Keep out of the reach of children.