A nurse is preparing to administer gentamicin, an aminoglycoside antibiotic, to a client with a serious gram-negative infection.
The nurse understands that this class of antibiotics has a potential adverse effect on which organ system?

Gentamicin is an aminoglycoside antibiotic that can causekidney damage, reduced urine output, blood in the urine, andnephrotoxicity.Patients with impaired renal function, advanced age, dehydration, and those who receive high doses or prolonged therapy are at an increased risk of toxicity.Serum concentrations of gentamicin should be monitored when feasible to assure adequate levels and to avoid potentially toxic levels.

Choice B is wrong because Hepatic is wrong because gentamicin does not have a significant adverse effect on the liver.However, some rare cases of transient hepatomegaly and splenomegaly have been reported.

Choice C is wrong because Cardiac is wrong because gentamicin does not directly affect the heart.However, it can cause electrolyte imbalance (low levels of calcium, potassium, or magnesium in the blood) which can affect the cardiac rhythm.It can also cause hypotension or hypertension in some cases.

Choice D is wrong because Hematologic is wrong because gentamicin does not cause blood disorders.However, it can cause anemia, leukopenia, granulocytopenia, and thrombocytopenia in patients with preexisting renal impairment or who receive concomitant therapy with other nephrotoxic or hematotoxic drugs.It can also cause bleeding due to hypoprothrombinemia in patients with renal failure or who are on anticoagulant therapy.

Nitrofurantoin is considered a narrow-spectrum drug because it is effective against only a limited range of bacteria, mainly gram-negative bacteria that cause urinary tract infections.

Some additional explanations are:

Choice A is wrong becauseCiprofloxacin is a broad-spectrum drug that can affect a wide range of bacteria, both gram-positive and gram-negative.

Choice C is wrong becauseTrimethoprim-sulfamethoxazole is also a broad-spectrum drug that can inhibit the growth of many types of bacteria, including some gram-positive and gram-negative bacteria.

Choice D is wrong because None of them is incorrect because nitrofurantoin is a narrow-spectrum drug as explained above.

Normal ranges for urinary tract infection microorganisms are:

• Escherichia coli: less than 10^5 CFU/mL

• Other bacteria: less than 10^4 CFU/mL