Question

Complete a concept map for antianginal and coagulation modifier drugs.

Answer 1

Answer: An antianginal is any drug used in the treatment of angina pectoris, a symptom of ischaemic heart disease.

• Drugs used are nitrates, beta blockers, or calcium channel blockers.
• Nitrates cause vasodilation of the venous capacitance vessels by stimulating the endothelium-derived relaxing factor (EDRF).
• The mechanism of action is as they are calcium channel blockers so it relax the muscles that make up the walls of arteries, increasing the blood supply to the heart.
• Examples are amlodipine, diltiazem, felodipine, nifedipine, verapamil.

*Coagulation modifiers that prevent blood clot formation are anticoagulants, antiplatelet drugs and thrombolytic drugs. Those that promote clot formation are fibrinolytics. Heparin antagonists and platelet-stimulating agents are used to reduce the risk of bleeding.

The mechanism of action involves as anticoagulants work in the clotting cascade but do so at different points.

• Heparin: Binds to the substance called antithrombi III, which turns off the three main activating factors: activated factor II ( THROMBI), activated factor X and activated factor IX. THROMBI is the most sensitive to the actions of heparin.
• LMWHs differ from heparin in that they are much more specific for activated factor X ( Xa) than for activated factor II ( thrombi). More predictable and frequent lab monitoring (aPPT) is not required.

• Warfarin ( Coumadin): inhibits Vitamin K synthesis by bacteria in the GI tract. This in turn inhibits production of factors II, VII, IX and X.
• Fondaparinux ( Arixtra): inhibits THROMBOSIS by its specific action against factor Xa alone.