[pharmaco midterms] cardiovascular

Hypertension (HTN) Definition

Sustained, reproducible increase in BP: systolic >140 mmHg or diastolic >90 mmHg. Goal: <120/80 mmHg.

HTN Complications

Stroke, heart failure, renal disease, and blindness.

BP Formula

BP = Cardiac Output (CO) × Vascular Resistance (R). CO = HR × Stroke Volume.

RAAS Function

Regulates blood volume, electrolyte balance, and systemic vascular resistance.

Beta-Blockers (-olol)

Decrease HR and contractility, lower CO, reduce sympathetic tone and renin release.

Beta-Blocker Adverse Effects

Bronchoconstriction (nonselective), bradycardia, orthostatic hypotension, fatigue, depression.

Alpha Blockers (-zosin)

Block alpha-1 receptors, reduce vascular resistance, used in HTN and BPH.

Prazosin Effect

Causes vasodilation in arteries and veins.

Alpha Blocker Adverse Effects

Reflex tachycardia, orthostatic hypotension.

Presynaptic Adrenergic Inhibitors

Inhibit NE release (e.g., Reserpine, Guanadrel), reduce sympathetic tone.

Central Acting Agents

Alpha-2 or imidazoline agonists (e.g., clonidine, methyldopa), reduce sympathetic outflow.

Central Acting Agent Side Effects

Dry mouth, dizziness, sedation.

Vasodilators

Directly relax vascular smooth muscle via second messengers like cGMP.

Hydralazine Use

Emergency HTN and preeclampsia.

Minoxidil

Vasodilator used off-label for hair growth.

Nitric Oxide

Endogenous vasodilator for pulmonary hypertension.

Vasodilator Adverse Effects

Reflex tachycardia, orthostatic hypotension, headache, nausea.

Thiazide Diuretics

Inhibit Na⁺ reabsorption in early distal tubule; superior for preventing cardiac events.

Loop Diuretics

Inhibit Na⁺/Cl⁻ reabsorption in loop of Henle (e.g., Furosemide).

K⁺-Sparing Diuretics

Prevent K⁺ loss (e.g., Spironolactone).

Diuretic Adverse Effects

Hypokalemia, orthostatic hypotension, weakness, confusion, mood changes.

ACE Inhibitors (-pril)

Inhibit Angiotensin I → II conversion, decrease BP, prevent vascular remodeling.

ARBs (-sartan)

Block angiotensin II receptors, lower BP without dry cough.

ACE Inhibitor Side Effects

Dry cough, angioedema, renal problems, dizziness, chest pain.

Calcium Channel Blockers (-dipine)

Inhibit calcium influx, promote vasodilation, lower resistance.

Dihydropyridines

Act on vascular smooth muscle (e.g., Nifedipine).

Non-Dihydropyridines

Act on myocardial cells to reduce HR and contractility.

CCB Adverse Effects

Reflex tachycardia, MI risk, pedal edema, arrhythmias.

Ganglionic Blockers

Nicotinic cholinergic antagonists that block sympathetic and parasympathetic transmission.

Ganglionic Blocker Side Effects

GI distress, urinary retention, visual disturbances.

Rehab Concerns with Antihypertensives

Monitor orthostatic hypotension; avoid systemic heat; beta-blockers blunt HR response.

Arrhythmia Definition

Any abnormal cardiac rhythm including bradycardia, tachycardia, or irregular rhythm.

Class I Antiarrhythmics

Sodium channel blockers; proarrhythmic risk, especially in HF and MI.

Class I Side Effects

Dizziness, visual disturbance, GI problems.

Class II Antiarrhythmics

Beta-blockers reduce sympathetic activity, HR, AV node conduction.

Class II Side Effects

Bradycardia, bronchoconstriction.

Class III Antiarrhythmics

Potassium channel blockers; prolong repolarization; treat VT and VF.

Amiodarone

Class III agent with effects of all four classes; risk of pulmonary, thyroid, liver toxicity.

Class IV Antiarrhythmics

Calcium channel blockers; affect SA/AV node, treat SVT and AF.

Class IV Side Effects

Bradycardia, dizziness, headache.

Non-Pharmacologic Arrhythmia Tx

Includes pacemakers, defibrillators, ablation.

Angina Pathophysiology

Caused by mismatch between O₂ supply and demand → ischemia.

Organic Nitrates

Converted to nitric oxide, cause vasodilation, reduce preload/afterload.

Nitroglycerin

Common nitrate for angina, various administration routes.

Nitrate Side Effects

Headache, dizziness, orthostatic hypotension.

Heart Failure Causes

Myocardial damage, workload, and neurohumoral compensation.

Inotropic Drugs

Increase cardiac contractility (e.g., Digoxin, Dobutamine, Milrinone).

Digoxin

Secondary agent in HF; narrow therapeutic index.

Anticoagulants

Prevent venous clots; treat DVT, embolism; used in Afib and post-surgery.

Heparin

IV anticoagulant enhancing antithrombin; immediate effect.

LMWHs

Subcutaneous anticoagulants targeting Factor Xa; safer, no monitoring needed.

Warfarin

Oral anticoagulant; inhibits vitamin K-dependent factors; monitored by PT/INR.

Direct Thrombin Inhibitors

Block thrombin activity (e.g., Dabigatran); reduce stroke risk in Afib.

Factor Xa Inhibitors

Inhibit Factor Xa (e.g., Apixaban, Rivaroxaban); oral use for cardiac patients.

Anticoagulant Side Effects

Hemorrhage, thrombocytopenia, GI distress.

Aspirin (ASA)

Irreversibly inhibits COX → ↓ TXA2; prevents arterial thrombosis.

ADP Receptor Blockers

Block platelet activation signal; prevent MI, stroke post-stent.

GPIIb/IIIa Inhibitors

Block platelet fibrinogen receptor; strong platelet inhibition during PCI.

Other Antiplatelets

Dipyridamole, Cilostazol, Pentoxifylline; used in stroke or PAD.

Fibrinolytics

Dissolve clots via plasmin activation; used for MI, stroke, PE.

Streptokinase/Urokinase

Activate plasminogen; used IV in emergencies.

tPA (Alteplase)

Recombinant fibrinolytic used for stroke and MI.

Fibrinolytic Side Effects

Hemorrhage, GI bleeding, bruising, allergic reactions.

Antifibrinolytics

Prevent excessive clot breakdown (e.g., Tranexamic acid, Amicar).

Antifibrinolytic Side Effects

Nausea, dizziness, headache.

Dyslipidemia

Elevated lipids in blood → atherosclerosis, clot risk.

Statins

Inhibit HMG-CoA reductase → ↓ LDL, TG; ↑ HDL; CV risk ↓ by 50%.

Statin Side Effects

Myopathy, rhabdomyolysis, peripheral neuropathy.

Fibric Acids

Activate PPAR-α; ↓ TGs, ↑ HDL; used in diabetes-related dyslipidemia.

Fibric Acid Side Effects

Myopathy, especially with statins.

Bile Acid Binders

Bind GI bile acids → ↓ cholesterol; may improve glucose in diabetes.

Niacin

↓ LDL/TG, ↑ HDL; safe with statins; causes flushing.

Ezetimibe

Inhibits cholesterol absorption; ↓ LDL; combined with statins.

Dyslipidemia Rehab Concerns

Promote exercise/diet; watch for statin-induced myopathy.