13: Alpha blockers and Ca channel blockers Flashcards
(17 cards)
Which subtype of alpha receptor is located on the prostate?
Alpha1b
Which alpha blocker is alpha 1a specific?
Tamsulosin
Alpha blockers are ___ line therapy for hypertension alongside ___ and ____
Third line
ACEi and diuretic
What is a phaeochromocytoma? How is this managed perioperatively?
- Tumour of the SNS
- Given phenoxybenazmine perioperatively to reduce surge in NE
Which drug is most helpful in hypertensive men with prostate symptoms?
Doxazosin
What are teh side effects of alpha blockers?
- Orthostatic hypotension
- Lassitude (tiredness)
- Nasal stuffiness
- Dry mouth
- Urinary incontinence
Why are the side effects of phenoxymenzamine so pronounced?
- Irreversible alpha blocker (a1 > a2)
- Antihistamine, anticholinergic, blocks serotonin receptors
What advice would you give someone on an alpha blocker?
- Stand up slowly
- Take first dose at night time
What are the indications for Ca channel blockers?
- Hypertension
- Angina
- Arrhythmias
- Vasospasm
What is the role of Ca channel blockers in arrhythmias?
Slow down heart rate but are NOT anti arrhythmic
What are the 3 classes of Ca channel blockers and examples of each?
- Dihydropyridine - nifedipine, felodipine, amlodipine
- Benzothiazepine - diltiazem
- Phenylalkylamine - verapamil
How are Ca channel blockers usually prepared?
All oral, IV of diltiazem and verapamil
What are the side effects of:
- Dihydropiridines?
- Phenylalylkamines?
- Nifedipine: flushing, headache, oedema
- Verapamil: heart block, -ve inotrope, constipation
Diltiazem/verapamil can be used with beta blockers
Diltiazem (slow down HR in AF)
What are some important drug interactions of verapamil?
- Inhibits CYP450 (statins)
- Inhibits PGP (digoxin, cyclosporin)
What is the first line therapy for angina? Why?
- Beta blockers
- Reduce heart rate and cardiac work
What is the suffix for alpha blockers?
- osin
