Hypertension Flashcards
What are the stages of treatment for hypertension?
BPM > 135/85 = monitor every 5yrs
135/85 < BPM < 149/94 = start drug treatment if co-morbidity
BPM > 150/95 = start drug treatment
What are the NICE guidelines in treating hypertensive patients?
Black or 55 and over = calcium-channel blocker followed by ACE inhibitor
T2 diabetes or under 55 & not black = ACE inhib followed by calcium-channel blocker
What do clearance, half-life and time-to-peak plasma levels mean?
Clearance = total blood that is cleared by all organs per min
Half-life= time required for conc. of drug to half
Time-to-peak plasma = faster absorption = less time taken to peak
What time of day does blood pressure increase most rapidly and which calcium blocker is most effective to use and why?
In the morning
Use amlodipine bcos has a longer time to peak plasma levels so provides longer, more stable plasma conc. over time
What’s the difference between pro-drug and active drug?
Pro-drug = inactive until metabolised
Active drug - takes effect immediately
Why do thiazide like diuretics get excreted in the urine unchanged?
They need to go from the blood to the basolateral side of proximal tubule to apical side of proximal tubule before exerting an effect on NACL transporter so it cannot be metabolised before this
Why do thiazide-like diuretics lead to hypokalaemia?
They inhibit NA/CL transporter on the Distal Convoluted Tubule meaning there is more Na+ in tubular lumen around the collecting duct, some of this is therefore re absorbed by the Na+/K+ATPase at the expense of K+
What is the action mechanism of ACE inhibitors? What are some examples?
Ramipril, Lisonopril, Perindopril
Inhibit angiotensin converting enzyme from converting angiotensin I to angiotensin II
What are the side effects of ace inhibitors?
Cough
Hypotension
Hyperkalaemia
Foetal injury- avoid in pregnant women
Renal failure
What is the action mechanism of Calcium Chanel blockers?
What are some examples?
Amlodipine, Felodipine
Block L-type calcium channels on vascular smooth muscle causing vasodilation and reducing peripheral resistance
What are the side effects of calcium channel blockers?
Ankle odoema
Constipation
Palpitations
Headaches
What is the action mechanism of thiazide-like diuretics?
Block Na+/Cl- cotransporter in early DCT increasing osmolarity of tubule fluid which decreases the osmotic gradient for water réabsorption in collecting duct
What are the side effects of thiazide-like diuretics?
Hypokalaemia
Hyponatraemia
Metabolic alkalosis
Hypercalcaemia
Hyperglycaemia
What is the action mechanism for Angiotensin receptor blockers? What are some examples?
Losartan, Canderstan
Non competitive antagonist at AT1 receptor on kidneys and vasculature
What are the side effects of angiotensin receptor blockers?
Hypotension
Hyperkalaemia
Fœtal injury- not for pregnant women
