Digitalis And Other Imp Drugs For The Management Of Heart Failure

Mode of Action

Di gi tal is indu ces the Ca ion inf lux th us enh ances the con tr ac tio n of myocar di um and t he con tr ac til it y inc rea ses the vent ricul ar ej ecti on. (ion ot ropi c

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Indications congestive cardiac failure - systolic failure cardiac arrhythmias - atrial fibrillation - atrial flutter - paroxysmal supraventricular tachycardia

Contraindications - Hypokalemia: enhances digitalis toxicity by increasing itsbinding to Na/K ATPase - Elderly, renal and severe hepatic disease - Myocardial infraction - Thyrotoxicosis: reduces responsiveness to digitalis - Myxoedema: elimination is slow , cumulative toxicity - Ventricular tachycardia: may leadto ventricular fibrillation - Partial A-V block : may converted to complete block - Acute myocardiis: prone to arrhythmias - Wolf-parkinson-white syndrome: VF may occur

Side effects 

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Extra cardiac: gastric irritation, mesentric vasoconstriction, restlessness, hyperapnoea Cardiac: many kind of arrhythmias, AV block

Digoxin toxicity 

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Inhibition of Na/K ATPase is clearly involved in the toxic action of the digitalis. At high doses there is depletion of intracellular K, toxicity is partially reversed by infusing k and the toxicity of the digitalis also may be due to Ca loading therapeutic index is low. Preparations: 0.5mg tab., 0.05mg/ml pediatric elixir, 0.5mg/2ml Ing.

A loop diuretics inhibitors of Na/K/2Cl ion cotransport

Dose: 20-80 mg once daily in the morning, in renal insufficiency upto 200mg qd given iv or im, in pulmonary edema 40-80mg iv. Side effect: hypotension, dehydration, electrolyte depletion, tinnitus, sensitivity to light , rashes.

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Thiazides, inhibitors of Na/Cl symport Dose: 500-2000 mg 6-12 hoursly Side effects: hypokalemia, dilutional hyponatremia, hearing loss, GIT and CNS disturbances. Aldosteron antagonist, k sparing diuretics Dose: 25-50 mg BD-QID Side effects: drowsiness, confusion, abdominal upset, hirsutism, gynecomastia, most common hyperkalemia , irregular menstruation.

Dose: 50mg in 5 ml Ing. Side effects: palpitaion, nervousness, vomitimg, perspiration, pain in abdomen, lactic acidosis. Dose: Captopril 25 mg tab Side effect: hypotension, hyperkalemia, cough, rashes, dizziness

1.These all are the contraindication of Digoxin except: a. b.

c. d.

Hypokalemia Paroxysmal Supraventricular Tachycardia Partial AV block myxedema

2. All of the following statement is true about frusemide except: a. b.

c.

d.

It is a loop diuretics The commonest complication is hyperkalemia It commonly act on acending limb of loop of henle It inhibits the Na/K/2Cl cotransport

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