PT
● MODULE 08 / 20
Cardiovascular Pharmacology
Study blood pressure, ischemia, heart failure, rhythm control and lipid lowering through hemodynamic mechanisms.
Quick revision ↓ Medical Dictionary
FULL CHAPTER EXPLANATION
Deep Learning — Module 08
Read this section in sequence. It moves from drug targets to therapeutic effects, adverse reactions and safe use.
01
Blood pressure and the renin-angiotensin system
Blood pressure reflects cardiac output and vascular resistance. ACE inhibitors reduce angiotensin II formation and reduce bradykinin breakdown; ARBs block angiotensin AT1 receptors. Both can increase potassium and alter renal function, and neither is appropriate in pregnancy. ACE inhibitor cough relates partly to bradykinin. Dihydropyridine calcium-channel blockers mainly dilate arteries, whereas verapamil and diltiazem also suppress cardiac nodal conduction and contractility. Drug selection depends on comorbidity and monitoring.
02
Angina and nitrates
Ischemic pain reflects imbalance between myocardial oxygen demand and supply. Nitrates release nitric-oxide-related signaling, increase cyclic GMP and predominantly dilate veins at usual therapeutic exposures, reducing preload and wall stress. Headache, hypotension and tolerance are important limitations. Combining nitrates with phosphodiesterase-5 inhibitors can cause dangerous hypotension. Beta blockers can reduce myocardial oxygen demand; calcium-channel blockers have differing vascular and cardiac effects. Relief of pain is not proof that infarction has been excluded.
03
Heart failure and inotropes
Reduced-ejection-fraction heart failure treatment combines agents that improve outcomes with medicines that relieve congestion. Renin-angiotensin pathway therapies, selected beta blockers, mineralocorticoid antagonists and SGLT2 inhibitors have distinct roles; loop diuretics mainly relieve fluid overload. Digoxin inhibits sodium-potassium ATPase, increasing intracellular calcium and vagal influence. Its narrow therapeutic margin, renal elimination and susceptibility to electrolyte disturbances require care. Positive inotropy alone does not prove long-term survival benefit.
04
Antiarrhythmic mechanisms
Class I agents block sodium channels, class II are beta blockers, class III commonly prolong repolarization through potassium-channel effects, and class IV are non-dihydropyridine calcium-channel blockers. The classification simplifies drugs with multiple actions. Prolonged QT can predispose to torsades de pointes. Adenosine briefly suppresses AV nodal conduction and is useful in selected regular supraventricular tachycardias under monitored protocols. Rhythm, stability and underlying heart disease determine suitability; one antiarrhythmic is not appropriate for every tachycardia.
05
Lipids and practical follow-up
Statins inhibit HMG-CoA reductase and increase hepatic LDL receptor-mediated clearance. Ezetimibe reduces intestinal cholesterol uptake; PCSK9 inhibition preserves LDL receptors; fibrates primarily address triglyceride-rich lipoprotein metabolism through PPAR-alpha. Monitor for clinically significant muscle symptoms and relevant interactions rather than assuming every ache proves toxicity. Follow blood pressure, pulse, volume status, renal function and electrolytes as appropriate. A drug-class mechanism informs choice but does not replace current patient-specific cardiovascular guidance.
High-Yield Revision
- ACE inhibitors and ARBs can both cause hyperkalemia.
- Nitrates plus PDE-5 inhibitors can cause severe hypotension.
- A medicine that relieves congestion does not automatically improve survival.
Common Exam & Concept Pitfalls
- Do not use verapamil as though it were identical to amlodipine.
- Antiarrhythmics can themselves provoke arrhythmias.
Sources & Further Reading
Curriculum scope checked 23 September 2026. These original study notes summarize established principles; current institutional guidance and product information govern clinical use. Faculty review is pending.
RAHBAR study structure: target → drug action → therapeutic use → adverse effects → monitoring. Use institutional curriculum and faculty guidance for local sequencing, practical requirements and assessment specifications.