HTN Flashcards
Thiazide diuretics
Bendroflumethiazide
Chlortalidone
Indapamide
Metolazone
Bendroflumethiazide drug class
Thiazide diuretic
Bendroflumethiazide targets
Na+ Cl
where is Bendroflumethiazides target (what part of the kidney)
DCT
Bendroflumethiazide moa
Inhibits sodium and chloride reabsorption = Natriuresis and reduction in blood volume and pressure
Bendroflumethiazide important side effects
electrolyte imbalance
Bendroflumethiazide causes the excretion of
sodium, chloride, and water
Bendroflumethiazide may inhibit
carbonic anhydrases in the smooth muscle
what does Chlortalidone inhibit
odium ion transport across the renal tubular epithelium
where does Chlortalidone work
ascending limb of the loop of Henle
what else does Chlortalidone decrease
potassium
Chlortalidone class
thiazide-like diuretics
Chlortalidone stimulates synthesis of
hypotensive prostaglandin PGE2
Chlortalidone blocks
rectifier potassium current
Metolazone class
thiazide-like diuretics
Metolazone length of action
long
Metolazone actions
lower BP
potassium loss
Metolazone inhibits
sodium reabsorption
where does Metolazone work
cortical diluting site
Loop diuretics
Furosemide
Bumetanide
Furosemide target
Na+ K+ 2Cl symporter
where is Furosemides target in the kidney
thick ascending limb of the loop of Henlé
Furosemide moa
Prevents the transport of sodium from the lumen of the loop of Henle into the basolateral interstitium. Consequently, the lumen becomes more hypertonic while the interstitium becomes less hypertonic, which in turn diminishes the osmotic gradient for water reabsorption throughout the nephron
important adverse effects of Furosemide
Electrolyte distubances
Metabolic disturbances
Ototoxicity; Nephrotoxicity; Hepatic encephalopathy
which part does Furosemide bind to
Chloride binding site
Bumetanide drug class
loop D
Potassium-sparing diuretics
Amiloride
Spironolactone
amiloride moa
inhibits sodium reabsorption predominantly in the collecting ducts
how strong is spironolactone
weak
spironolactone moa
competing for intracellular aldosterone receptor
where in the kidney does spironolactone work
DCT
difference between propanolol and atenolol
atenolol does not have a negative inotropic effect
high dose atenolol can do what
competitively block beta(2)-adrenergic responses in the bronchial and vascular smooth muscles
describe propanolol
non-cardioselective beta-adrenergic antagonist
Calcium channel blockers
Amlodipine
Felodipine
Diltiazem
Verapamil
amlodipine target
L-type calcium channels (Dihydropyridines favour depolarised closed Ca++)
amlodipine moa
Inhibit influx of calcium ions into vascular smooth muscle cells through L-type calcium channels = Decreased arterial smooth muscle contratility leading to vasodilatation
common adverse effects of amlodipine
Headache; Tachycardia; Peripheral oedema
bad side effect of amlodipine
Heart failure in patients with poor left ventricular function
where are depolarised closed Ca++ commonly found
vascular smooth muscle cells
Verapamil class
Class IV anti-arrhythmia agent
Verapamil inhibits
voltage-dependent calcium channels
what happens when Verapamil blocks L type calcium channels
reduction in ionotropy and chronotropy, reducing heart rate and blood pressure
how is Verapamil given
IV
first line ACE
ramipril
what does ACE do
converts angiotensin I to angiotensin II
how does angiotensin II work
Stimulation of secretion of aldosterone from the adrenal cortex
Stimulation of Vasopression secretion from the posterior pituitary gland.
Through direct arterial vasoconstriction
angiotensin II affect of hypothalamus
stimulates hypothalamic neurons = thirst
what does ACE deactivate
bradykinin
ACE side effect
cough
Losartan class
angiotensin II receptor blocker
good thing about ARBs to ACEi
do not affect bradykinin = no cough
Doxazosin class
alpha-adrenergic blocking agent
Doxazosin inhibits
selective inhibitor of the α1-adrenoceptors
where is Doxazosin target
smooth muscle
Spironolactone drug class
Aldosterone-dependent potassium sparing diuretics
Spironolactone target
Intracellular aldosterone receptors (mineralocortocoid receptors (MR)) in the renal tubules
Spironolactone important adverse effect
Hyperkalaemia
Gynaecomastia/hypogonadism, impotence in males, menstrual irregularities
AKI
when to stop Spironolactone
V and D - dehydration
bisoprolol moa
Inhibits binding of noradrenaline, this inhibits activation of adenylyl cyclase enzymes leading to reduced cyclic AMP. This in turn leads to reduced intracellular calcium levels.
bisoprolol overall aim on the heart
Reduce contractility, reduce heart rate, reduce blood pressure, reduce cardiac
bisoprolol important side effects
Hypotension Bronchoconstriction Bradycardia and heart block Hypoglycaemia Peripheral vasoconstriction = intermittent claudication and Raynaud’s phenomenon
bisoprolol in diabetics risk
may mask hypo symptoms
what does cardioselective mean
β1 only
examples of cardioselective BB
Atenolol, Metoprolol
examples of non cardio selective BB
Carvedilo
noradrenaline is released from
released from sympathetic adrenergic neurones
Reduced contractility proper name
negative intropy
reduce heart rate proper name
negative chronotropy
diltiazem drug class
Rate-limiting calcium channel blocker
diltiazem target
L-type calcium channels
diltiazem moa
Inhibit influx of calcium ions into cardiomyocytes through L-type calcium channels
diltiazem affect on heart
Negative inotropic effect – decreases cardiac contractility
diltiazem risks
Sino-atrial and AV block
ramipril moa
Inhibits synthesis of angiotensin II leading to vascular smooth muscle relaxation and vasodilatation
common side effects of ramipril
Persistent dry cough
(First dose) hypotension
bad side effects of ramipril
Acute renal failure
Hyperkalaemia
Angioedema, hypersensitivity reactions
what to do if ramipril acuses a cough
swap to ARB
when to take first ramipril
night
1st line drug in those below 55
Ramipril
sartan target
Angiotensin II AT1 receptor
sartan side effects
1st dose hypotension
sartan bad side effects
Hyperkalaemia
Acute renal failure
doxazosin drug class
α1 specific Alpha blockers
doxazosin target
Alpha adrenoceptor
doxazosin moa
inhibits binding of noradrenaline
This inhibits activation of phospholipase-C enzyme leading to reduced inositol triphosphate; this in turn blocks the downstream phosphorylation cascade.
doxazosin bad side effect
Postural hypotension