Drugs online research references
Am J Cardiol. 1994 Jan 27;73(3):34A-38A.
Hemodynamic and electrophysiologic effects of first- and second-generation calcium antagonists.
Vetrovec GW.
Department of Internal Medicine, Medical College of Virginia, Richmond.
The calcium antagonists currently available exert significantly different in vitro and in vivo electrophysiologic, hemodynamic, and contractile effects on cardiovascular function, mediated through differential cardiac and vascular smooth muscle responses to calcium channel blockade. These differences have important implications regarding choice of agent in specific clinical conditions, such as sinus or atrioventricular nodal disease, depressed left ventricular function, or congestive heart failure--conditions that may coexist with angina or hypertension. Recognizing and utilizing the properties of the different calcium antagonists is important to ensure maximally effective clinical outcomes. For example, in patients with hypertrophic cardiomyopathy and supraventricular arrhythmias, verapamil is singularly effective, whereas in post-myocardial infarction patients with pulmonary congestion, diltiazem may produce an added risk. Calcium antagonists of the dihydropyridine class, such as nifedipine and amlodipine, have the greatest peripheral vasoselective effects and thus the greatest potential to reduce afterload, minimizing direct left ventricular depression of contractility. Despite favorable effects of calcium antagonists, most of the agents currently available are not clearly safe in congestive heart failure and may adversely affect left ventricular function. However, newer calcium antagonists such as amlodipine are being investigated with regard to their safety in congestive heart failure.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8310974&dopt=Abstract
Acta Pharmacol Toxicol (Copenh). 1985;57 Suppl 2:21-30.
Haemodynamic and electrophysiologic effects of diltiazem.
Bourassa MG.
This review describes the haemodynamic and electrophysiologic properties of diltiazem and shows how these effects may, in some clinical situations, favour the choice of this drug as an antianginal and antiarrhythmic agent. Compared to nifedipine and verapamil, diltiazem has the distinct advantage of being a negative chronotropic agent and thus has the potential of leading to a greater reduction in myocardial oxygen consumption; it does not affect cardiac output, left ventricular end diastolic pressure, and ejection fraction in patients with an adequately preserved left ventricular function; finally, it possesses a longer duration of action and fewer side effects, even at relatively high calcium entry blocking doses, than the other major calcium entry blockers.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=4061103&dopt=Abstract
Am J Cardiol. 1982 Feb 18;49(3):629-35.
Comparative clinical electrophysiologic effects of diltiazem, verapamil and nifedipine: a review.
Mitchell LB, Schroeder JS, Mason JW.
The slow channel blocking agents--diltiazem, verapamil and nifedipine--have generated clinical interest for the treatment of a variety of cardiovascular disorders. These agents, despite a similar basic mechanism of action, produce disparate clinical cardiac electrophysiologic effects in human beings. In usual doses, the acute administration of diltiazem slows heart rate. Verapamil and nifedipine, however, increase heart rate. Although diltiazem and verapamil produce equivalent slowing of atrioventricular (A-V) nodal conduction, verapamil prolongs A-V nodal refractoriness to a greater degree. In contrast, nifedipine facilitates A-V nodal conduction and shortens A-V nodal refractoriness. Knowledge of these differences may aid in the appropriate selection of specific slow channel blocking agents in specific clinical situations.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6277182&dopt=Abstract
Herbs and Pharmaceuticals Online ||
Hair Million herbal formula for hair loss and hair growth ||
Wellstreet online pharmacy for click-order prescription medications ||
Altace Online Pharmacy ||
Rx Drugs USA, Prescription Drugs Online Pharmacy ||
Insurance plans and information ||
Insurance policies for all purposes ||
Antibiotics and prescription medications online literature ||