๐370: Cardiac Drugs Flashcards
What are HMG-CoA Reductase Inhibitors?
Statins
What is the mechanism of action of statins?
Inhibit rate limiting enzyme in cholesterol synthesis (HMG-CoA reductase)
- Lower LDL
- Increase HDL
- Decrease Triglycerides
What is the onset and max efficacy of statins?
Onset: 2 weeks
Max efficacy: 4-6 weeks
What are the side effects of statins?
- Hepatotoxicity
- Myopathy (muscle ache, weakness)
(Rarely rhabdomyolysis) โ> monitor creatine kinase (CK)
What are some drug interactions for statins?
- CYP450 inhibitors (statin accumulation and inc myopathy)
- Grapefruit juice
- Vibrates, niacin (myopathy)
What is the dosing and administration of statins?
Dose once daily at bedtime
PO only
(HMG-CoA reductase highest at night)
What is a HMG-CoA Reductase Inhibitor prototype?
Atrovastatin (Lipitor)
What is a Fibric Acid Derivative prototype?
Febofibrate (LipidilMicro, LipidilSupra)
What is another name for Fibric Acid Derivatives?
Fibrates
What are Fibrates used for?
CAD: Most effective agents to decrease Triglycerides
Also inc HDL, small effect on LDL
What is the mechanism of action for Fibrates?
- Breakdown Triglycerides and facilitate HDL formation
2. Enhances cholesterol elimination in bile
What is the onset of Fibrates?
3-4 weeks
What are the side effects of Fibrates?
- Gallstones (cholesterol inc in bike)
- GI effects (nausea, dyspepsia, diarrhea)
- Myopathy
- Rash
- Hepatotoxicity (monitor LFTs)
What are some drug interactions with Fibrates?
- Statin (myopathy)
2. Warfarin (bleeding, monitor INR)
What is the dosing and administration of Fibrates?
Once daily with meal
PO only
What is another name for Bile Acid Sequestrants?
Resins
What is a prototype of Resins?
Cholestyramine (Questran)
What are Resins used for?
CAD
Modest decrease LDL
Small inc HDL and Triglycerides
What is the mechanism of action of Resins?
- Cholesterol required to make bile acids
- Resins bind bile acids in gut to increase excretion
- Increased bile acid production in liver
- Removes cholesterol from blood
What is the onset and max effect of Resins?
Onset: 1 week
Max effect: 4 weeks
What are side effects of Resins?
Not absorbed by body, eliminated in feces
- only agent safe in pregnancy
- GI side effects (nausea, constipation, bloating, abdo pain, flatulence)
What are some drug interactions with Resins?
Reduce absorption of:
- Fat soluble vitamins (ADEK)
- Anionic drugs (digoxin, warfarin, levothyroxine, thiazides, fibrates)
What are anti-adrenergic drugs?
- B-Blockers
2. alpha1-adrenergic blockers
Which drugs work on the RAAS system?
- ACE inhibitors
- Angiotensin receptor blockers (ARBs)
- Aldosterone antagonists
What is the goal of drug therapy for angina?
Reducing oxygen demand
What are 5 clinical uses for Beta-Blockers?
- Prevent angina attacks
- Acute MI
- Heart failure
- Hypertension
- Dysrhythmias
What is the suffix for Beta-Blockers?
-olol
What is a non-selective Beta-Blocker?
Propranolol
Blocks both B1 and B2 receptors
What is a cardioselective B-Blocker?
Metoprolol
Blocks B1 receptors only
What is a vasodilating B-Blocker?
Carvedilol
Blocks alpha-1-adrenergic receptors and B-receptors
What is the mechanism of action for Beta-Blockers?
- Block B1 receptors in heart
- Dec HR, contractility, and AV conduction
- Dec renin release from kidneys
- Dec peripheral vascular resistance
What are side effects of B-Blockers?
- Bradycardia
- Decreased Cardiac Output (CO)
- CNS effects (sleep, fatigue, depression)
Non-selective agents:
- Bronchoconstriction
- Hypoglycaemia
What are some drug interactions with B-Blockers?
CCBs (excessive cardio suppression)
What is the dosing and administration of B-Blockers?
Orally once-twice daily
IV forms available
โ> Rebound cardiac excitation if stopped abruptly
(Tachycardia, dysrhythmia, angina, MI)
What is the suffix for alpha1-adrenergic blockers?
-osin
What is the main clinical use for alpha1-adrenergic blockers?
- Hypertension
2. Benign Prostatic Hyperplasia (BPH)
What is the mechanism of action of alpha1-adrenergic blockers?
Block alpha1 receptors on arterioles and veins, preventing vasoconstriction
What are side effects of A1ABs?
- Orthostatic hypotension
- Reflex increased HR (May be managed with B-Blockers)
- Nasal congestion
- Sexual dysfunction (inhibition of ejaculation)