L1 B Alpha Beta Adrenergic Modulators Flashcards
(34 cards)
What is the primary focus of cardiovascular (CV) pharmacology?
To understand drug classes, mechanisms of action, therapeutic indications, potential adverse drug reactions, and pharmacokinetics.
CV pharmacology is crucial for prescribing and understanding patient care.
What is the first-line treatment for hypertension (HTN) in patients with compelling indications?
A low dose of an ACE Inhibitor or ARB.
Compelling indications include diabetes, coronary disease risk, and heart failure.
What are some common drug options if lifestyle modifications are insufficient for controlling blood pressure?
ACE Inhibitors/ARBs, Calcium Channel Blockers (CCBs), Thiazide diuretics, β-blockers.
A single drug class controls BP in 40-50% of patients.
What is Doxazosin primarily used for?
Adjunct antihypertensive treatment and benign prostatic hyperplasia.
Doxazosin is a selective α1 blocker.
What are some side effects of α1-blockers like Doxazosin?
- Postural hypotension
- Depression
- Drowsiness
- Nasal stuffiness
- Increased GI motility
- Inhibit ejaculation
- Urinary incontinence
What is the mechanism of action for centrally acting α2 agonists like Clonidine?
Reduces sympathetic outflow and increases parasympathetic activity, lowering blood pressure.
Clonidine decreases noradrenaline release.
What are the three generations of β-blockers?
- 1st generation: Propranolol (non-selective)
- 2nd generation: Metoprolol, Atenolol (β1-selective)
- 3rd generation: Carvedilol (β1, β2 & α1 antagonist)
What are the main therapeutic uses of β-blockers?
- Rate control
- Angina
- Myocardial infarction
- Heart failure
- Hypertension (not first line)
- Glaucoma
- Anxiety
True or False: β-blockers are commonly used as the first-line treatment for hypertension.
False.
1st and 2nd generation β-blockers are generally not indicated for hypertension.
What pharmacological actions do β-blockers provide?
- Negative chronotropic effect
- Negative inotropic effect
- Decrease renal renin output
- Decrease conduction through AV node
What are some adverse drug reactions (ADRs) associated with β-blockers?
- Bronchospasm
- Decreased cardiac output
- Fatigue
- Peripheral vasoconstriction
- Nightmares
- Worsened lipid profiles
Fill in the blank: Doxazosin has better _______ profile compared to other adrenergic modulators.
LDL/HDL
What is a significant pharmacokinetic difference between hydrophilic and lipophilic β-blockers?
Hydrophilic β-blockers have a lower chance of drug interactions and food interference.
They are mainly excreted unchanged via the renal route.
What is the effect of metoprolol on β-adrenoceptors?
It acts as an inverse agonist, inhibiting basal β-AR activity.
Metoprolol has stronger inverse agonist effects compared to carvedilol.
What is the pharmacogenomic relevance of the ADRB1 gene in relation to β-blockers?
Single nucleotide polymorphisms can affect receptor sensitivity to β-blockers.
C-allele carriers respond better than G-allele carriers.
What is the recommended method for tapering off β-blockers?
Withdraw/taper slowly over several months to prevent rebound effects.
This is important to avoid withdrawal symptoms.
What is the primary action of β-blockers on cardiac output?
Reduction of cardiac output through decreased heart rate and force of contraction.
This leads to decreased oxygen consumption.
What is the significance of a single nucleotide polymorphism in the ADRB1 gene?
It can lead to amino acid Gly → Arg substitution, increasing receptor sensitivity to beta blockers.
C-allele responds better to beta blocker treatment than G-allele based on the 1000 Genome Project.
What is the effect of a Ser → Gly substitution in the ADRB1 gene?
It results in a smaller amount of β-receptors and loss of response to beta blockers.
What genetic variations can affect the metabolism of beta blockers?
Variations in the CYP2D6 gene can affect how fast beta blockers are metabolized, leading to ultra-rapid or poor metaboliser classifications.
Fill in the blank: Poor metabolism of metoprolol affects _______.
cardioselectivity.
What is atenolol?
Primarily a cardioselective adrenergic receptor blocker with β1 adrenergic receptor blockade properties.
How does atenolol exert its anti-anginal action?
Through a negative inotropic and negative chronotropic effect, reducing cardiac oxygen demand and RAS activation.
How may atenolol plasma concentrations be affected in patients with chronic kidney disease?
Plasma half-life may be prolonged due to renal excretion; dose-reduction should be considered.
