Pharmacology Flashcards
What is the main function for antiarrythmic drugs?
They are used to restore normal cardiac activity by targeting proarrhythmic areas of heart.
Which drugs are apart of Class Ia Antiarrhythmics?
Double - Disopyramide
Quarter- Quinidine
Pounder - Procainamide
” Double Quarter pounder”
Which drugs are apart of the Class Ib Antiarrhythmics?
Lettuce - Lidocaine
Mayo - Mexiletine
Pickles - Phenytoin
Tomato - Tocainide
on my Burger
” Lettuce, Mayo, Pickles on my B(Ib)urger”
Which drugs are apart of Class Ic Antiarrhythmics?
Can - Ic
get
Fries - Flecainide
Please- Propafenone
What is the Mechanism of action for Class 1 Antiarrhythmics?
The are Sodium ( Na+ ) channels blockers. They leave fewer channels available to open in response to membrane depolarization thereby raising threshold for Action potential firing and slowing rate of depolarisation.
Which phase is affected by Class 1 antiarrhythmics drugs?
Phase 0 ( depolarization )
Class 1 antyarrythmic drugs decreases re-entry and prevent arrhythmia by ?
- Decreasing conduction velocity
- Increasing refractory periods of ventricular myocytes.
Which Class 1 antiarrhtyhmic drug provides a marked Na+ block?
Class Ic
Which class 1 antiarrhtyhmic drug prolongs action potential?
Class Ia
Which class 1 antiarrhtyhmic drug shortens action potential?
Class Ib
Which Which class 1 antiarrhtyhmic drug does not change action potential?
Class Ic
What is a diuretic?
- Drug that ↑ volume of urine flow
- Primarily inhibit Na + reabsorption
What are the classification of diuretics?
- Thiazide/ Thiazide like diuretics
- Loop diuretics
- K+ sparing Na channel inhibitors
- Aldosterone receptor antagonists
What are examples of Thiazide/ thiazide-like diuretics?
Metolazone
Indapamide
Chlorthalidone
Chlorothiazide
Hydrochlorothiazide (prototype)
“MICCH is thiazide”
What are examples of K+ sparing Na channel inhibitors?
Eplerenone
Amiloride
Triamterene
Spironolactone
” K+ sparing Na channel inhibitors EATS everytime !”
What are examples of Loop diuretics?
Tammy- Torsemide
Eat- Ethacrynic acid
Bunny’s - Bumetanide
Fruit - Furosemide
Loops
” Tammy Eat Bunny’s Fruit LOOPS’
What are the aldosterone receptor antagonists?
SpironolactONE
EplerenONE
AldosterONE inhibitors
Fill in the blanks. “An example of an osmotic diuretic is ____________ and a carbonic anhydrase inhibitor is __________.”
Osmotic diuretics - Mannitol
Carbonic anhydrase inhibitors - Acetazolamide
What is the principal site of action for Loop diuretics?
Loop of Henle duuhhh
What is the principal site of action for Thiazides?
The distal convoluted tubules
The cortical collecting tubules is the principal site of action for which drug?
– K sparing – amiloride, triamterene & spironolactone , eplerenone
What is the mechanism of action for Thiazides?
It inhibits Na+/Cl- transporter on the luminal side of Distal Convolutes Tubule.
What are the adverse effects of Thiazides?
HYPERcalcemia
HYPERuricemia
HYPERglycemia
Hypokalemia
Hypomagnesemia
Hyponatremia
Hypocholemia
Increase in LDL cholesterol & triglycerides
What is the Mechanism of Action for Loop Dieuretics?
Inhibition of Na+/K+/2Cl- co-transport system in the thick ascending limb of the Loop of Henle.
What are the clinical uses of Loop Diuretics?
- Oedematous states ( pulmonary oedema due to CHF, ascites due to cirrhosis)
*↑ urine output in acute renal failure
- Hypercalcemia, hyperkalemia, hypermagnesemia
What are the adverse effects of Loop Diuretics?
- HYPERuricemia
- Metabolic alkalosis
- Hypokalemia
- Volume depletion
- Ototoxicity ( reversible)
- Hypokalemia
- Volume depletion
- Hypocalcemia
- Hypomagnesemia
- Hyperuricemia
- Interstitial nephritis
True or False? Loop diuretics DECREASES calcium content of urine.
FALSE!! It INCREASES calcium content in urine.
What is the mechanism of action for Spironolactone?
Competitive antagonist of aldosterone at aldosterone receptor in DCT.
*Binds to receptor preventing formation of mediator proteins that stimulate Na+/K+ pump
What is the mechanism of Amiloride & Triamterene?
Directly inhibits Na+ reabsorption in collecting tubule – works INDEPENDENT of presence of aldosterone.
What is the clinical use of Amiloride & Triamterene?
Can be used in the treatment of Hypoaldosteronism
What is the Clinical uses of Spironolactone?
- Hypertension – often added to other diuretics (thiazides) to limit K + loss
- Oedema 2 0 CHF, cirrhosis, nephrotic syndrome
- Primary hyperaldosteronism
What are the adverse effects of Spironolactone?
- Hyperkalemia (esp. in patients w renal impairment)
- Hyponatremia
*Metabolic acidosis [intracellular shift of H+] - Irregular menstrual cycle
- Gynaecomastia & impotence
True or False? Amiloride causes HYPERcalcemia while Spironolactone causes HYPOcalcemia.
TRUE!!
What are the examples of α-1 blockers ?
Prazosin
Doxazosin
Terazosin
What are the clinical uses for Prazosin?
- Hypertension
- BPH – relaxes smooth m in bladder neck
- Raynaud’s phenomenon (vasospam → digital ischemia)
What are the adverse effects of Prazosin?
- Orthostatic hypotension
- Syncope
- Nasal congestion
- Dry mouth
- Nightmares
- Sexual dysfunction
- Lethargy
Fill in the blanks. “ Propanol on the pulmonary (β 2): cells causes ________.
Bronchoconstriction - by blocking β 2 adrenoceptor mediated relaxation of bronchial smooth muscle
Fill in the blanks. “ Propanol on the β 2 receptors on the Juxtaglomerular cells causes ________.
A decrease in Renin secretion - ( blocks β 1 – adrenoceptors on the juxtaglomerular apparatus)
What are the clinical uses of Propranolol ?
- Ischemic heart disease, hypertension, arrhythmias, aortic dissection.
- Portal hypertension: splanchnic vasodilation →↓ portal pressures &↓ GI bleeding.
- Thyrotoxicosis, anxiety disorders
- Migraine prophylaxis
What are the adverse effects of Propranolol?
- Sinus bradycardia, AV block, hypotension, CHF
- Fatigue, depression, ↓libido
- May precipitate bronchospasm
- ↑ VLDL, ↓ HDL
Metoprolol is a what type of drug ?
β 1 adrenoceptor competitive antagonist
Which drug can be used in the treatment of chronic Congestive Heart failure?
Carvedilol
What are the contraindications of Carvedilol?
Acute CHF
Heart block
Asthma
COPD
What are the adverse effects of Carvedilol?
- Dizziness
- Fatigue
- Hypotension
- Weight gain
- Hyperglycaemia
- Diarrhoea
What are the clinical uses of Statins?
*Drug therapy of choice to reduce hypercholesterolemia & achieve LDL cholesterol goals in pts at risk for /or with CAD.
- Reduces cardiovascular mortality and risk of myocardial infarction , coronary revascularization and stroke
What are the lipid modulating properties of statins?
- Reduces lipid content of atherosclerotic lesions & promotes plaque stability.
- Decrease vulnerability of plaque to rupture.
- Decrease likelihood of thrombus formation & vascular occlusion
What are the Cardioprotective effects of statins?
- Improve endothelial function by enhanced synthesis of NO.
- Diminish vulnerability of lipoproteins to oxidation —-> inhibiting unregulated uptake of modified LDL by macrophages.
*Suppress inflammation - key component of atherogenesis
- Promote plaque stability by inhibiting monocyte penetration into arterial wall & reducing macrophage secretion of metalloproteinases - degrade & weaken fibrous caps of plaques
Which statin drug should not be taken at night?
Atorvastatin & Rosuvastatin
Which statin drugs are inhibited in the liver by Cytochrome P450 CYP3A4 ?
Lovastatin, Simvastatin, Atorvastatin
Which substance is a Potent inhibitor of Cytochrome P450 CYP3A4 ?
Grapefruit Juice
Fill in the blanks. “ ___________ &______________ are metabolised by CYP2C9
Rosuvastatin & Fluvastatin
What are the adverse effects of HMG CoA Reductase inhibitors?
- Elevation of serum transaminase
- ↑ risk of diabetes ( largely in prediabetics)
- Constipation
- GI upset
- Myalgia
- Myopathy
- Rhabdomyolysis
- Headache
- Rash
- Cataracts
- ↓ Coenzyme Q 10
- Cognitive impairment (rare) (amnesia, memory impairment, confusion)
What is the effect of Ezetimibe?
WResults in ↓total cholesterol and LDL-C with minimal effects on HDL & trigylcerides
What drugs should Ezetimibe be combined with to increase its efficacy?
Statins
What is the MOA of Ezetimibe?
Inhibits cholesterol absorption at small intestine brush border.
What are examples of Bile acid binding resins / sequestrants ?
Cholestyramine
Colestipol
Colesevelam
What is the MOA of Bile acid resins/sequestrants?
Prevent intestinal
reabsorption of bile acids; liver must use cholesterol to make more.
- Resins bind negatively charged bile acids in small intestines, forming insoluble complexes that are then excreted in faeces.
- Loss of bile acids stimulates liver to increase conversion of stored cholesterol into new bile acids.
What are examples are Fibric acid derivatives (Fibrates)?
GemFIBRozil
FenoFIBRate
BezaFIBRate
CiproFIBRate
What are the mechanisms of action of Fibric acid derivatives (Fibrates)>
Reduces plasma triglycerides
- ↑ activity of lipoprotein lipase → promote catabolism of VLDL (rich in TGs).
- ↓hepatic synthesis & secretion of VLDL.
- ↑ HDL ( ↓ TG → ↓exchange of cholesteryl esters from HDL to TG – rich lipoproteins)
What are the adverse effects of Fabric acid derivatives?
- GI upset
- Skin rash
- Alopecia
- Myalgias
- Lithiasis (formation of gall stones due to biliary excretion of cholesterol)
- Abnormal LFTs
What is the mechanism of Niacin (Vitamin B3)?
- Inhibits lipolysis (hormone- sensitive lipase) in adipose tissue;↓ transport of FFA to the liver and ↓ hepatic synthesis of triglycerides. It reduces hepatic VLDL synthesis
What are the adverse effects of Niacin?
- Severe flushing (prostaglandin mediated, may be reduced if aspirin taken beforehand/ taking sustained-release preparations)
- Pruritus
- Headache
- Nausea
- Constipation
↑ transaminases
- Hyperglycaemia
*Hyperuricemia (inhibits tubular secretion of uric acid)
What are examples of PCSK9 (proprotein convertase subtilisin/ kexin type 9) inhibitors ?
Alirocumab, evolocumab
What is the MOA of PCSK9 inhibitors?
They inactivate the LDL-receptor degradation, increasing amount of LDL removed from bloodstream.
PCSK9 inhibitors decrease LDLR degradation by PCSK9 → improve LDL clearance & ↓ LDL
What are the examples of ACE inhibitors?
Captopril
Enalapril
Lisinopril
Ramipri
Trandolapril
all the prils lol
What is the mechanism of action for ACE inhibitors?
Reversibly inhibit ACE which catalyzes Angiotensin I → Angiotensin II → blocking RAAS axis
Inhibition ofACE also prevents inactivation ofbradykinin, a potent vasodilator.
What are the adverse effects of ACE inhibitors ?
- Cough (persistent dry cough)
- Angioedema (both due to
increase bradykinin; contra indicated in C l esterase inhibitor deficiency}, - Teratogen (fetal renal malformations),
*Creatinine increase (because of decrease GFR), - Hyperkalemia,
- Hypotension.
CATCHH
Used with
caution in bilateral renal artery stenosis because ACE inhibitors will further l CFR - renal failure.
What are the examples of Angiotensin II receptor blockers (ARB’s)?
Losartan
Candesartan
Eprosartan
Irbesartan
Olmesartan
Telmisartan
Valsartan
” the sartans”
What is the mechanism of action of Angiotensin II blockers (ARB’s)?
Competitive AT11 receptor blocker but they DO NOT increase bradykinin
What are the adverse effects of ARB’s?
- dizziness
- nausea
- angioedema
- hyperkalemia esp. in patients taking K sparing diuretics
- fatigue
- hypoglycemia
- chest pain
- diarrhoea
- hypotension
Which drug is a direct inhibitor of renin?
Aliskiren
What are examples of Calcium channel clockers?
Dihydropyridine (DHP)
- Nifedipine
- Amlodipine
- Felodipine
- Nicardipine
- Isradipine
- Nisoldipine
- Clevidipine
- Nimodipine
Non- dihydropyridine
- Verapamil
- Diltiazem
What is the mechanism of action for Dihydropyridine (DHP) CCB?
CCB binds to L type Ca 2+ channels inhibiting inward movement of Ca 2+, decreasing the rate of recovery of these channels
What are the clinical uses of Nifedipine?
- Hypertension
- Ischaemic heart disease
- Relief of coronary vasospasm in Prinzmetal’s angina
- Pulmonary hypertension
- Raynaud’s phenomenon
What are the adverse effects of Nifedipine?
- Ripheral oedema
- Dizziness
- Flushing
- Headache
- Heartburn
- Hypotension
- CHF
- Nausea
What is the Main clinical uses of Methyldopa?
It is used to treat Hypertension in Pregnancy .
What are rapidly - acting Nitrates?
Nitroglycerin
What are examples of long-acting nitrates?
- Sustained- release nitroglycerin
- Isosorbide dinitrate
- Isosorbide mononitrate
What is the MOA of Nitrolycerine?
Nitrates via nitric oxide (NO), stimulate guanylate
cyclase→↑ cGMP → activation of
cGMP-dependent protein kinases.
This causes ↓intracellular Ca 2+ & activation of
myosin light chain (MLC) phosphatase, both of
which result in MLC dephosphorylation
What are the clinical uses of Nitroglycerine?
Treatment of angina (often w β- blocker * to
minimize reflex tachycardia that occurs w
nitrates)
Congestive heart failure
Hypertension esp. in patients w coronary disease
Which drug is a PDE V inhibitor?
Sildenafil
What is the MOA of PDE V inhibitor (Sildenafil)?
PDE V inactivates cGMP - ↑cGMP→ MLC dephosphorylation → smooth m
relaxation
What is the MOA Ranolazine ( Anti-anginal drug )?
- Inhibits the late phase of sodium current thereby reducing diastolic wall tension and oxygen consumption. Does not affect heart rate or blood pressure.
What is the MOA of Trimetazidine ( abtianginal drug)?
Trimetazidine inhibits the utilisation of FFA for energy production by inhibiting the enzyme mitochondrial 3-ketoacyl CoA thiolase ( 3-KAT) activity in Beta oxidation
What are the clinical uses of Trimetazidine (anti-anginal drug)?
Angina
Vertigo, Tinnitus
