Pharmacokinetics and Pharmacodynamics

Benazepril 

Pharmacodynamics 

Benazepril is categorized as an angiotensin-converting enzyme. The drug is a prodrug, and when hydrolyzed in the presence of esterases it leads to the activation of its active Benazeprilat. It is used for the treatment of various cases that include prevention of stroke, heart failure, and hypertension, reduction of proteinuria and renal disease for nephropathy patients, myocardial infarction and cardiac death in high-risk patients. This chemical substance is used in both veterinary and human medicine. Angiotensin-converting enzyme (ACE) is peptidyl dipeptidase that catalyzes the conversion of angiotensin 1 to angiotensin two that is a vasoconstrictor substance. The presence of angiotensin 2 triggers aldosterone secretion from the cortex of the adrenal. 

Pharmacokinetics 

Benazepril has Benazeprilat as its active content. Benazeprilat competes for the active binding site with angiotensin 1 to bind to the ACE. This scenario blocks conversation of angiotensin 1 to angiotensin 2.The inhibitory effect leads the reduction of angiotensin 2 effect in plasma. Angiotensin 2 is the vasoconstrictor and its concentration being lower means decreased blood pressure. In the same process, the baroreceptor reflex mechanisms are stimulated reducing vasopressor activity and also aldosterone secretion. Benazeprilat is also known to act on kinase 2 which is an enzyme similar to ACE, and it degrades the vasodilator bradykinin. Its mode of action is by inhibitors. 

Variables 

The drug reduces absorption of potassium 

Food slows down but does not prevent absorption 

Some herbs e.g. cayenne, ephedra, ginger, bayberry, kola, ginseng, and licorice inhibits the antihypertensive effect of the drug 

Take with no regards to meals 

High intake of salt may counter the antihypertensive effect. 

Bisoprolol 

Pharmacodynamics 

The drug belongs to the class beta blockers which is a competitive cardioselective β1 adrenergic antagonist. Epinephrine activates β1-receptors in the heart increasing pressure and heart rate, in turn, increasing the consumption of oxygen. Bisoprolol lower blood pressure and the heart rate hence used to reduce the work of the heart. It also hinders the production of renin (cause constriction of blood vessels) from the kidneys causing. It is lipophilic, and it shows no intrinsic sympathomimetic activity. 

Pharmacokinetics 

The drug blocks stimulation of catecholamine in a selective manner reducing systole pressure diastole pressure, cardiac output, heart rate and possibly orthostatic hypertension. In greater dose, the drug competitively blocks β2-adrenergic receptors of vascular smooth muscle and bronchial muscles causing vasodilation and bronchospasm. 

Variables 

Overdose causes congestive heart failure accompanied by fatigue, swollen, legs, feet, ankles, shortness of breath and sudden increase in body weight. It also causes Low blood sugar, Low blood pressure, slow heart rate and difficulty in breathing. 

References 

Burchum, J. R., & Rosenthal, L. D. (2016). Lehne’s Pharmacology for nursing care. (9th Ed.). St. Louis, MO: Elsevier. 

DrugBank. (n.d.). Retrieved July 9, 2017, from https://www.drugbank.ca/drugs/DB00542#pharmacology 

DrugBank. (n.d.). Retrieved July 9, 2017, from 

https://www.drugbank.ca/drugs/DB00612