Common adverse effects of isoproterenol include tachycardia with potential proarrhythmia and reduced diastolic filling time.

• A. Bradycardia
• B. Hypertension
• C. Renal failure
• D. Tachycardia and proarrhythmia

Answer: (D)

Isoproterenol is a nonselective beta-adrenergic agonist that stimulates beta-1 receptors in the heart, causing increased heart rate and contractility. This rapid stimulation speeds up the SA node and AV conduction, so you get tachycardia. The quicker heart rate shortens diastolic filling time, reducing ventricular filling and myocardial perfusion during diastole. The heightened beta-adrenergic activity also increases the heart’s tendency to develop abnormal impulses, which raises the risk of proarrhythmias. Together, tachycardia with potential proarrhythmia and reduced diastolic filling time are the typical adverse effects to expect with isoproterenol.

Bradycardia wouldn’t fit because the drug speeds up the heart. Hypertension is not typical since isoproterenol often causes vasodilation and may lower blood pressure, while renal failure isn’t a direct common effect of this agent.