This property increases myocardial oxygen delivery in patients with coronary artery spasm, and is responsible for the effectiveness of nifedipine in vasospastic (Prinzmetal's or variant) angina. Atrial or ventricular dysrhythmias each occurred in about one patient in 150.In post-marketing experience, there have been rare reports of exfoliative dermatitis caused by nifedipine. 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: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 upon starting nifedipine or at the time of dosage increase. J Control Release. Clipboard, Search History, and several other advanced features are temporarily unavailable. Studies have demonstrated that the increase in active tension reflects an increase in cytosolic free calcium.Nifedipine is a peripheral arterial vasodilator which acts directly on vascular smooth muscle. Whether this effect plays any role in classical angina is not clear, but studies of exercise tolerance have not shown an increase in the maximum exercise rate-pressure product, a widely accepted measure of oxygen utilization. These include: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. Within several hours of ingestion, nausea, vomiting, and generalized edema developed. Drug absorption from nifedipine hydrophilic matrix extended-release (ER) tablet-comparison with an osmotic pump tablet and effect of food Author links open overlay panel Bertil Abrahamsson a Magne Alpsten b Björn Bake c Ulf E Jonsson a Maria Eriksson-Lepkowska a Annhild Larsson b The mechanism of this effect is not established.It is important to taper beta blockers if possible, rather than stopping them abruptly before beginning nifedipine. With the exception of leg cramps, the incidence of these side effects was similar to that of placebo alone.Other adverse reactions were reported sporadically with an incidence of 1.0% or less. This site needs JavaScript to work properly. Drug absorption from nifedipine hydrophilic matrix extended-release (ER) tablet-comparison with an osmotic pump tablet and effect of food. And why the change? Clearance of nifedipine would be expected to be prolonged in patients with impaired liver function. This suggests that, in general, relief of spasm or dilation of coronary arteries is not an important factor in classical angina.Nifedipine regularly reduces arterial pressure at rest and at a given level of exercise by dilating peripheral arterioles and reducing the total peripheral vascular resistance (afterload) against which the heart works. Nifedipine extended release tablet depends for its action on the existence of an osmotic gradient between the contents of the bi-layer core and fluid in the gastrointestinal tract.