8-3 Pharmacology

q123456's version from 2016-06-01 18:51

antidysrhythmic drugs

Question Answer
antidysrhythmic drugsantidysrhythmic drugs class I
block sodium channels/reduce the maximum rate of depolarisation during phase 0.
cause QRS prolongation but has little effect on the QT interval duration
treatment for MI induced ventricular arrhythmia?lidocaine, class IB

antidysrhythmic drugs class II
β-adrenoceptor antagonists olol+carvedilol
do not affect the QRS, QT interval durations, prolong the PR interval

antidysrhythmic drugs class III (li)
amiodarone, ibutilide and dofetilide (lid)
blocking the potassium channels>>>cardiac repolarisation>>>prolong the cardiac action potential>>>prolonged QT interval
aminodarone SE: thyroid dysfunction, hepatitis, skin discoloration and pulmonary fibrosis

antidysrhythmic drugs class IV (verapamil and diltiazem)
slow inward Ca2+ current>>>slow conduction in the SA and AV nodes
occurs in phase 0
carotid sinus massageincreases baroreceptor firing
increase cardiac parasympathetic tone
slow conduction through the AV node
prolongs the AV node refractory period
class 1A>>>slow phase 0 depolarization and prolonged phase 3 repolarizationDisopyramide
class 1Blidocaine
class 1C sodium channel binding strength is IC>IA>IBmoricizine
Rapid iv injection of __into the patients with palpitation results in resolution of the arrhythmia but flushing, chest buring and shortness of breath?adenosine
1st for supraventricular tachycardia
verapamil or propranolol, which one is used to treat atrial fibrillation in patient with COPD?COPD is contraindication to the use of non selective beta blockers. so verapamil.


Question Answer
nitratevenodilation>>>retention of blood in the venous system>>>decreased cardiac preload (decrease left ventricular volume during diastole)>>>decrease cardiac work and oxygen demand
venodilation on the coronary arterioles>>>dilate the collateral vessel>>>allow more blood through to the underperfused region/a decrease in afterload
which of the nitrate agents has the highest bioavailability if given orally?isosorbide mononitrate
nitrates>>>anginavasodilators>>>decrease in BP>>>Reflex tachycardia>>>increase myocardial oxygen demand>>>prevented by beta-blockers (metoprolol).
around the clock nitrate administration rapidly results in?development of tolerance to nitrates
a nitrate free interval must be provided every day in patients, why?development of tolerance to nitrates

Phosphodiesterase inhibitors

Question Answer
cGMP accumualationphosphodiesterase inhibitors (erectile dysfunction)/nitrates
phosphodiesterase inhibitorsincrease cAMP>>>VASODIALTION
erectile dysfunction


Question Answer
Sulfonylureas and Meglitinidesdirect effect on insulin secretion
binds to ATP gated K+channel>>>inhibits efflux of K+
before each meal
sulfonylureas SE: sulfa drugs. anaphylactic reaction KA9-3. Glipizide
meglitinides: Repaglinide: Rapid absorption/short acting
Side Effects:
Interactions with: Alcohol, Beta blockers, NSAID's, Diuretics, antibiotics
weight gain
Biguanidesdecrease glucose production from liver
Metformin (Glucophage)
more effective when used with Sulfonylureas
SE: Renal
Alpha Gludosidase InhibitorsTake with first bite of each meal.
Blocks pancreatic alpha-amylase and alpha-glucosidases to reduce the rate of digestion of carbohydrates
Delays absorption of carbohydrates in small intestines
Acarbose (Precose), Miglitol (Glyset)
used alone or with other OADs,
SE: diarrhea, flatulence
Thiazolidinediones (TZDs)bind to PPARr, a nuclear regulatory protein involved in transcription of genes regulating glucose and fat metabolism
Pioglitazone (Actose), Rosigutazone (Avandia)
SE: hepatotoxicity and fluid retention/weight gain>>>congestive heart failure
insulinpostprandial short acting:regular, lispro, aspart and glulisine
long acting of insulin: NPH, Glargine and detemir
insulin is the medicaiton of choice for treatment of gestational diabetes mellitus
Reduce oral contraceptive effectThiazolidinediones (TZD's)
direct effect on insulin secretionsulfonylureas and meglitinides (not metformin and rosiglitazone)
the most crucial gene regulated by PPARrAdiponectin upregulation/decreasing insulin resistance


Question Answer
isoproterenolincreases cardiac contractility by acting on myocardial B1 adrenergic, relaxation of vascular smooth muscle by binds to B2 receptors
regualtion of reninmacula densa
intrarenal baroreceptor
beta adrenergic receptors:NE binds to beta 1 receptor on juxtaglomerular cells
beta adrenergic blockers inhibit renin release by blocking the beta-1 receptor mediated pathway
medications that can cause hyperkalemiaNonselective beta-darenergic blockers

angioedema: ACE inhibitors>>>bradykinin accumulation>>>vasodilator/increas vascular permeability
chronic cough


K+sparing diuretics
block the epithelial sodium channel>>>inhibit sodium reabsorption in the late distal convoluted tubules


orthostatic hypotensiona fall of >20 mm in systolic or >10 mm in diastolic when assuming an upright posture. under stimulation of a1-adrenoreceptors (SE of a adrenergic blockers)
Calcium channel blockersvascular smooth muscle>>>reduce contraction of the arteries>>> increase in arterial diameter (CCBs do not work on venous smooth muscle).
SE:patients with Hypertension has bilateral ankle swelling and flushing
the patient's medications include metoprolol, atorvastatin and aspirinacute renal failure when addition of erythromycin
acetazolamide diuretic inhibits carbonic anhydrase
loop diureticsinhibit the Na/K/2Cl symporters in the thick ascending limb of the loop of henle.
Hypokalemia secondary to CHF medication?loop diuretics
Skip heartbeats, ECG shows premature ventricular contractions
thiazide diureticshyperuricemia/hypercalcemia/hyperglycemia/hyperlipidemia
hypo: hypokalemia/hypotension
mannitolpulmonary edema
dobutamineB-adrenergic agonist>>>B1>>>cAMP>>>contractility, increased cardiac output, decrease in ventricular filling pressures, increased HR>>>increased myocardial oxygen consumption
B1 receptors are found in cardiac tissue and on renal juxtaglomerular cells but not on vascular smooth muscle.blockade of the B1 receptor leads to decreasing cAMP levels in cardiac and renal tissue without affecting cAMP levels in vascular smooth mucles.
lower HRB-adrenergic blockers

non dihydropyridine calcium channel blocker

cardiac glycosides

amiodarone and sotalol
essential hypertension without CHF or diabetesthiazide diuretic
hypertension with CHF or diabetesACE inhibitors


Question Answer
beta blocker overdoseglucagon>>>cAMP increase>>>release of intracellular calcium during muscle contraction>>>HR and cardiac contractility
glucagon1 increase glycogen catabolism and gluconeogenesis and ketogenesis >>>severe hypoglycemia
2 increase HR and contractility>>>reversing the cardiac effects of an overdose of β-blocking agents because of its ability to increase cAMP production in the heart.
3 increase insulin
hypoglycemiacorrect: intramsclular glucagon
wrong: intramuscular glucose
alpha -2>>>Gidecrease insulin secretion
beta-2>>>Gs, muscarinic M3>>>Gqincrease insulin secretion
glucagon>>>Gsincrease insulin secretion, why? During hypoglycemia glucagon is stimulated ----> glucagon makes sugar ----> sugar is in the blood BUT As we all know sugar by it self wont be taken up by the cell ----> Insulin then is called in to push it into the cell


Question Answer
symptoms of heart failuretachycardia, decreased exercise tolerance, shortness of breath and cardiomegaly>>>peripheral and pulmonary edema
SuccinylcholineDepolarizing skeletal muscle relaxant SE: hyperK+
Digoxinvagus nerve>>>decreased rate of AV conduction
block Na-K ATPase in cardiac myocytes>>>increased intracellular calcium con.c>>>increase cardiac contractility

1)arrhythmia due to hyperK+
2)supraventricular tachycardia KA31-44
oral activated charcoal
correct serum potassium
digoxin specific antibody fragments to bind digoxin

1) patients with atrial fibrillation and heart failure has nausea, vomiting, anorexia and confusion, serum potassium 5.7 mEq/l
2) A 65 year old man with CHF has upset stomach, he has a history of disturbed color perception, anorexia, nausea, vomiting and diarrhea that have worsened over the past 2 weeks.


Question Answer
GemfibrozilIsactivator of PPARα
increase in the synthesis of lipoprotein lipase

Gemfibrozil+Bile acid resins
Imbalance between bile salts and cholesterol= Gallstones. too much cholesterol or too little bile salts>>> Gallstones.
ezetimibeinhibit the GI absorption of cholesterol
statinsHMG CoA reductase
inhibit hepatic cholesterol synthesis>>>increased LDL receptor>>>uptake of circulation
decreasing the syntheisis of hepatic triglyceride and VLDL>>>decreases VLDL conversion to LDL>>>decrease LDL

gouty arthritis

increase insulin resistance>>>increase diabetes medications when treated with niacin for hyperlipidemia

vasodilatory effects

niacin's side effects are flushing, which may be mediated by prostaglandins
pretreatment with aspirin
total serum cholesterol level is 155 mg/dl, with a high density lipoprotein level of 30 mg/dl. which of the lipid lowering agents would be most effective in preventing future cardiovascular events in this patient?the patient has a low HDL (<40 mg/dL in men, <50 mg/dLin women)>>> statins not niacin (Even niacin is the most effective agent for increasing HDL, however, the cardiovascular benefits of niacin are less than those from statins, even in patients with low HDL)
atorvastatin + gemfibrozilelevated serum creatine kinase and muscle pain


Question Answer
mesnaheorrhagic cystitis, can be prevented by aggressive hydration and by the coadministration of mesna
right sided endocarditistricuspid valve occurs in IV drug user, S aureus.

inserts into the cell membrane >>>leak
right sided endocarditis
SE: Myopathy and elevated CK

SE: nephrotoxicity and red man (itching and rash)

inhibits bacterial protein synthesis by 50S
SE:thrombocytopenia, serotonin syndrome and potic neurits
drug induced lupushydralazine
high risk drugs for the development of lupushydralazine
selective arteriolar vasodilation cause?reductions in arterial pressure>>>stimulate baroreceptor >>>increased HR, contractility and increased renin activity>>>sodium and fluid retention
hydralazine and minoxidildirect arteriolar vasodilators>>>tachycardia and edema
doxorubicincauses dilated cardimyopathy