Cardiovascular System Flashcards
Renin is secreted by
JG cells of macula densa of affereent arteriole
Organs that angiotensin 2 acts (6)
Heart: increase force,rate,velocity
Bv: vasoconstriction
Kidney : sodium,water retention
Adrenal : aldosterone secretion
Brain: increase ADH, increasing thirst receptors —> plasma expansion
Peripheral nerves: activation of sympathetic system
ACEI …….TPR
Preload ,after load
Decreases
Decreases
All are carboxyl groups except
Captopril -sulfhydryl
Fosinopril: phosphinate
All are prodrug except …
Captopril
Lisinopril
Max and min bioavailability of ACEI
Max :70%: captopril
Min : 25%: lisinopril
All are excreted by kidney except
Fosinopril: liver:kidney = 50/50
Uses of ACEI and ARB
Home Care Makes Patient Definitely Strong
HTN
CHF
MI
PX of MI
DN
Scleroderma crisis
Use of aliskiren
Only HTN
Adverse effects of captopril
CAPTOPRIL
Cough
Angioneurotic Edema
Potassium high
Tetatogenic, taste prob
Other: fatigue,headache
Proteinuria-rare
Renal impairment
Itch
Low Bp -first dose hypotension- give 1/2 dose for 1st week then from 2nd week onwards full dose
C/I of captopril
Pregnancy
Allergy
Renal artery stenosis : u/l or b/l
Hyperkalemia
Antihypertensive that is also antidiabetic
Telmisartan - has PPAR gamma activating property
Known as cardio metabolic Sartan
Losartan in anticoagulation
Blocks thromboxane A2 , inhibit plt aggregation
( losartan activity is similar to aspirin, hence it’s also a uricosuric drug)
Adverse effects of aliskiren (4)
Angioneurotic edema
Hyperkalemia
Teratogenic
Hypotension
MOA of digoxin w.r.to HR
Decrease HR without decreasing myocardial oxygen consumption
Name 4 cardiac glycosides
Digoxin
Digitoxin
Ouabain
Strophanthin
Where are digitalis obtained from
Digoxin: Digitalis Lanata
Digitoxin: Digitalis purpura
Actions of digitalis (4)
- Heart:
Increase force of contraction
Increase excitability
Decrease velocity —> decrease HR - Blood vessels: vasodilation
- Kidney: diuresis
- CNS: activate CTZ —> N/V
Elimination of digitoxin vs digoxin
Oral availability
Digitoxin: hepatic
Digoxin: renal
Digitoxin: 90-100%
Digoxin: 60-80%
Plasma protein binding for digitoxin vs digoxin
Toxicity of digitoxin vs digoxin
Digitoxin: 95%
Digoxin: 25%
Digitoxin: >35ng/ml
Digoxin: >2ng/ml
Toxicity of digitalis
Hypokalemia
Hypercalcemia
Adverse effects of digitalis (3)
N/V
Yellow vision
Gynecomastia
ECG finding of digitalis (4)
Increase PR
Decrease QT
T wave inversion
ST depression
Antidote of digitalis
Anti-dig Fab fragments
Nitrates MOA (2)
Increase in CGMP which
1. Inhibit calcium channel
2. Inhibit MLCK phosphorylation
Uses of nitrates (6)
A: Angina pectoris
B: biliary colic
C : cyanide poisoning
D: dil ka daura: MI
E: esophageal spasm
F: failure : HF
How does nitrates work for cyanide poisoning?
- Hb—-> methb ( sodium nitrite)
- Methb——-> cyanohb ( cyanide)
- Cyanohb——-> methb + sodium thiocyanate (sodium thiosulfate)
Sodium thiocyanate gets excretes in urine
Adverse effects of nitrates
T: tolerance
D: dependence
S: skin rashes
R: reflex tachycardia
O: orthostatic hypotension
M: methb
C/I of nitrates (3)
- Right ventricular infarction
- Sildenafil
- HOCM
All nitrates undergo first pass metabolism except
Shortest acting nitrate:
Longest acting nitrate :
Isosorbide mononitrate
Shortest: GTN / Amyl nitrite
Longest: Pentaerythitol
MOA of nicorandil (2)
- K channel opener : hyperpolarizes smooth muscle membrane and relaxes it.
- Acts as nitric oxide donor- relaxes blood vessels by increasing cGMP
How does nicorandil exert cardio protective action?
Stimulates ischemic preconditioning —as a result of mitochondrial K ATP channels
Uses of nicorandil (2)
- 2nd line antianginal drug
- Resistant asthma
MOA of ivabradine
Blocks HCN channel responsible for pacemaker funny current - which regulates heart rate.
Another name for ivabradrine
Pure heart rate blocker
As it only blocks funny currents.
Uses of ivabradine (3)
- Stable angina
- Sinus tachycardia
- Stable with symptomatic chronic HF with resting HR >70bpm
Those on max tolerated beta blockers
Have c/I to beta blockers
Moa of ranolazine
Inhibit late inward sodium current.
Reduces diastolic wall tension and oxygen consumption
Not affect HR contractility.
Uses of ranolazine
Angina refractory to other therapies
Adverse effects of ranolazine (5)
Constipation
Dizziness
Headache
Nausea
Qt prolongation
MOA of trimetazidine. Use
Inhibits mitochondrial LC3KAT, responsible for fatty acid oxidation
Use: add on therapy in angina and post Mi
Different between dihydropyridines and non dihydropyridines
Dihydro: act on smooth muscle
More potent, lipophilic
Non dihydro: act on heart
Negative chrono,iono,dromo
MOA of CCB
Block voltage dependent calcium L type channels.