Which pharmacodynamic interaction is shown by concurrent use of Loop Diuretic and Aminoglycoside?

Which pharmacodynamic interaction is shown by concurrent use of Loop Diuretic and Aminoglycoside?

• A. Addition
• B. Potentiation
• C. Synergism
• D. Antagonism

Answer: (C)

When two drugs produce an effect that is greater than the sum of their individual effects, that’s synergy. Here, an aminoglycoside has known risks of nephrotoxicity and ototoxicity, and a loop diuretic can worsen those toxic effects. Their concurrent use can lead to more pronounced kidney and inner ear toxicity than would be anticipated from either drug alone, demonstrating a synergistic pharmacodynamic interaction. In practice, this means clinicians should use caution with this combination, monitor kidney function and hearing closely, and opt for the safest possible dosing if the combination is necessary.

When two drugs produce an effect that is greater than the sum of their individual effects, that’s synergy. Here, an aminoglycoside has known risks of nephrotoxicity and ototoxicity, and a loop diuretic can worsen those toxic effects. Their concurrent use can lead to more pronounced kidney and inner ear toxicity than would be anticipated from either drug alone, demonstrating a synergistic pharmacodynamic interaction. In practice, this means clinicians should use caution with this combination, monitor kidney function and hearing closely, and opt for the safest possible dosing if the combination is necessary.