PHARMA Flashcards
Nitrates
- Used in angina and CAD: potent vasodilators, lower Bp; control ischaemia
- Action: Enter vascular smooth muscle cells
Systemic hemodynamics - Decrease in myocardial oxygen demand
- Low doses: small amount of arterial dilatation
- Higher doses: BP falls, reducing wall stress
Coronary hemodynamics - Increase in coronary blood flow
Side effects - Headaches or light-headedness
Clinical context - Stable angina need supervision and encouragement
- Closely monitor any symptoms of new-onset chest pain particularly during exercise
- Cease activity and rest
- Be seated when GTN spray/oral sublingual nitrates administered
Cholesterol - lowering medications
- Action: Block enzyme activity leading to greater clearance of LDL cholesterol
- Side Effects: Nausea, constipation, diarrhea, myopathy
- Examples: HMG CoA reductase inhibitors (e.g., Atorvastatin, Rosuvastatin)
Anti-platelet Agent
- Action: Prevent blood clots and reduce the risk of cardiac events
- Classified: platelet aggregation inhibitors, Glycoprotein platelet inhibitors
- Side Effects: Bleeding propensity, peptic ulcer
- Examples: Glycoprotein IIb/IIIa inhibitors (e.g., Abciximab) for unstable angina
Beta-Blockers
- Peripheral: β-adrenoreceptors stimulation – vasodilation
- Cardiac: β-adrenoreceptor stimulation - increased heart rate, contractility
- Action: Reduce blood pressure by blocking epinephrine effects, leading to slower heart rates and decreased myocardial oxygen demand
- Side Effects: Bradycardia, fatigue, bronchospasm, difficulty with ADLs due to slowed or absent normal rapid increase in HR that accompanies exertion, bronchospasm due to stimulation of ß2-receptors in airway smooth muscle
- Clinical context: limit normal increase in HR seen during exercise, THUS DO not use HR as a target for training intensity
- Examples: Atenolol, Metoprolol
ACE inhibitors and Angiotensin II Receptor Blockers(ARBs)
- Action: Vasodilation, reduce sodium and water retention
- Side Effects: Cough, headache, dizziness
- Examples: Captopril (ACE inhibitor), Losartan (ARBs)
Angiotensin receptor neprilysin inhibitors
- Action: counteract maladaptive responses in heart failure by simultaneously suppressing the RAAS and enhancing the natriuretic peptide system
- Side Effects: Hypotension, hyperkalaemia, renal failure, cough and angioedema
- Examples: Entresto (Sacubitril/valsartan)
Calcium Channel Blocker
- Action: Inhibit calcium influx, leading to vasodilation and reduced myocardial contractility
- Side Effects: Headache, light-headedness
- Examples: Amlodipine, Verapamil
Diuretics
- Action: Reduce fluid retention and blood volume, aiding in heart failure management
- Examples: Loop diuretics (e.g., Frusemide), Thiazide diuretics (e.g., Hydrochlorothiazide)
Vasopressors and inotropes
- Action: Increase blood pressure and cardiac output in acute hypotension
- Examples: Norepinephrine (vasoconstrictor), Dobutamine (inotrope)
heart failure meds
Clinical context:
- Be familiar with effects and side effects
- Patients: combination of medications with different mechanisms of action and side effects
Side effects:
- ß blocker side effects
- e.g., bradycardia, fatigue or lethargy; dizziness; hyperkalaemia; oedema
Angiotensin-converting enzyme inhibitors & Angiotensin II receptor blockers
- Revision: Angiotensin II is primary vasoactive hormone of renin angiotensin aldosterone system
- Angiotensin II causes aldosterone stimulation, regulation of salt and water homeostasis
- Main difference between ACE inhibitors and ARBs – selective receptor activity
- ACE inhibitors: inhibits the inactivation of bradykinin (a potent vasodilator)
calcium
Actions:
- Inhibits calcium ion influx across cell membranes:
- Vascular smooth muscle cells (decreasing systemic vascular resistance) e.g., Amlodipine or cardiac muscle cells e.g., Verapamil which dilates main coronary arteries and coronary arterioles, both in normal and ischaemic regions, and inhibits coronary artery spasm
Side effects: Headache, light-headedness, flushing
acute hypotension
Clinical context: Commonly encountered in ICU where patients have low or a fluctuating blood pressure Administration: All are delivered intravenously via a central line or peripheral line
Side effects: Excessive vasoconstriction (peripheral ischaemia), hypertension, headache, hyperglycaemia, possibly glycosuria
Summary - Peripheral and Cardiac Receptor Stimulation
- Peripheral: α-adrenoreceptor stimulation – vasoconstriction; α2-adrenoreceptor inhibition – vasodilation. β-adrenoreceptors stimulation – vasodilation
- Cardiac: β-adrenoreceptor stimulation - increased heart rate, contractility, conduction velocity, and relaxation rate. Human heart has both β1- and β2-adrenoreceptor, with β2-adrenoceptors higher in the atria than in ventricular myocardium
