Hypertension + Heart Failure Flashcards
List 5 types of drugs used to treat hypertension
- ACE inhibitors (ACEi)
- Angiotensin Receptor Blockers (ARBs)
- Diuretics
- Calcium Channel Blockers (CCBs)
- Other agents used to treat ‘resistant hypertension’
Where is the enzyme ACE found?
Luminal surface of capillary endothelial cells, predominantly in the lung
Angiotensin II acts through AT1 and AT2 receptors.
List 3 actions via AT1
- Stimulation of Aldosterone production
- Vasoconstriction
- ADH release
(Sometimes, AT2 receptor effects oppose AT1 effects)
How can Angiotensin II be produced from Angiotensin I independently of ACE?
Give 2 examples of ACE Inhibitors
Via Chymases
- Lisinopril
- Ramipril
List 5 ADRs of using ACE Inhibitors
- Dry cough
- Hyperkalaemia
- Hypotension
- Renal failure (including Renal Artery Stenosis)
- Angio-oedema (More common in Afro-Caribbeans)
List 4 contra-indications for using ACE Inhibitors
- Renal artery stenosis
- Pregnancy
- AKI (CKD) too
- Angio-oedema
Give examples of 2 ARBs
Where do ARBs work?
- Losartan
- Candesartan
At AT1 receptors
Give 3 ADRs of ARBs
- Hypotension
- Hyperkalaemia
- Renal failure
Why are ARBs more effective than ACE Inhibitors at inhibiting Ang-II mediated vasoconstriction?
Ang-II can still be made from Ang-I by Chymases
List 3 contra-indications for using ARBs
- Renal artery stenosis
- AKI (CKD too)
- Pregnancy
Why don’t ARBs cause angio-oedema?
No buildup of Bradykinin (a substrate of ACE), which causes a dry cough and angio-oedema
How do CCBs work?
- Bind to Alpha-subunit of L-Type Calcium Channel (LTCC), reducing cellular Ca entry
- The different types of CCB have higher selectivity for either vascular smooth muscle or myocardium
(LTCCs are a type of VOCC)
What are the 3 types of CCBs?
- Dihydropyridines
Non-dihydropyridines;
- Phenylalkylamines
- Benzothiazapines
List some features of Dihydropyridine CCBs
Give 3 examples
- Selective for peripheral vasculature
- Little Chronotropic or Inotropic effect
- Amlodipine (Most common)
- Nifedipine
- Nimodipine
List features of Phenylalkylamine CCBs
Give an example
- Less peripheral selectivity
- Depresses SA node and slows AV conduction-> Negative Inotropy
- Verapamil
How do Benzothiazapine CCBs compare to Phenylalkylamines and Dihydropyridines
Give an example of a Benzothiazapine
Sit in the middle;
- Some action on peripheral vasculature
- Some action on SA and AV nodes
- Diltiazem
What drugs are the Primary anti-hypertensive agent in patients with low renin?
CCBs, as ARBs and ACEi are not likely to be very useful
Which Dihydropyridine CCB has selectivity for cerebral vasculature?
When can this be useful clinically?
- Nimodipine
- Useful for ischaemic effects of subarachnoid haemorrhage
List 4 ADRs of Dihydropyridine CCBs
- Ankle swelling
- Flushing
- Headaches (All due to vasodilation)
- Palpitations (compensatory tachycardia)
List 2 contra-indications of Dihydropyridine CCBs
- Aortic stenosis
- Unstable angina
How does Amlodipine interact with Simvastatin?
Can maintain plasma levels of Simvastatin-> Increased statin effect
Phenylalkylamine CCBs can be used for Arrythmia, Angina and Hypertension.
What are 3 side effects?
- Constipation
- Heart block and cardiac failure
- Bradycardia, if given by IV
List 2 contra-indications of Phenylalkylamine CCBs
- Poor LV function
- AV node delay
List 6 ADRs of Thiazide thiazide-like diuretics
- Hypokalaemia
- Hyperuricaema, can-> Gout
- Arrhythmia
- Hyperglycaemia
- Small increases in TAG and Cholesterol levels
- Hyponatraemia (not really a long term issue)
List 3 contra-indications of thiazide diuretics
- Gout
- Hypokalaemia
- Hyponatraemia
Step 1 in treating primary hypertension in what 2 groups involves use of CCBs
- Age >55
- Blacks (less likely to have high renin)
Why are ARBs and ACEi good for treating Type 2 diabetic nephropathy or Proteinuria?
“Two pronged approach”:
- Reduced peripheral resistance= Reduced BP
- Dilation of efferent arteriole= Reduced intraglomerular pressure
Suggest 3 drugs used to treat Resistant hypertension
- Spironolactone
- Alpha blockers
- Beta blockers
(Consider the blockers if K+ is already high)
What are 2 ADRs and contra-indications for Spironolactone
Side effects;
- Hyperkalaemia
- Gynaecomastia, Impotence, Menstrual irregularities (Androgenic properties)
Contra-indications;
- Hyperkalaemia
- Addision’s
How do Beta blockers work?
Decrease sympathetic tone by;
- Blocking NA
- Reducing myocardial contraction-> Reduced CO
- Also decreases renin secretion
List 3 Beta blockers
- Labetalol (Pregnant hypertensive emergency)
- Bisoprolol
- Metoprolol
List 5 ADRs of beta blockers
- Bronchospasm
- Heart block
- Raynaud’s (cold hands)
- Lethargy
- Impotence
List 2 contraindications of beta blockers
- Asthma (COPD too)
- Hepatic failure
Describe the interactions between beta blockers and Verapamil (Phenylalkylamine) and Diltiazem (Benzothiazapine)
Can cause asystole
Name an Alpha blocker
How do these work?
(Safe relatively in renal disease)
- Doxazosin
- Selectivity to Alpha 1 receptors, so reduce peripheral resistance
Alpha blockers also act on the urinary tract at the bladder neck and prostate.
Which one is used to treat BPH?
Tamsulosin
List 5 ADRs of Alpha blockers
- Postural hypotension (Contraindications)
- Dizziness
- Syncope
- Headaches
- Fatigue
Describe the interaction between Alpha blockers and Dihydropyridine CCBs (Amlodipine)
Can cause Oedema
List 4 factors that affect CO
- Heart rate
- Contractility
- Preload
- Afterload
Suggest 2 non-pharmacological managements of heart failure
- reduced salt intake
- liquid reduction
What 5 drug types are used in treating Heart Failure?
- ARBs
- ACEi
- Diuretics
- Beta blockers
- Spironolactone
What drugs are usually used to treat HF with reduced EF?
- Diuretics
- ACEi/ ARB + Beta Blocker
- can give Spironolactone as well
Are NSAIDs and ACEi contra-indicated?
Yes, can lead to nephrotoxicity
