A nurse who is caring for a preschooler should question a prescription for which of the following antibiotics?

The nurse should include tinnitus (ringing in the ears) as an adverse effect of gentamicin in the client's teaching. Gentamicin is an aminoglycoside antibiotic commonly used to treat bacterial infections. One of the potential side effects of gentamicin is damage to the inner ear, which can lead to tinnitus.

Tinnitus is a concerning symptom as it may indicate ototoxicity, which is damage to the structures of the inner ear responsible for hearing and balance. If the client experiences tinnitus while taking gentamicin, it is essential to notify the healthcare provider immediately to assess the severity of the issue and consider appropriate interventions.

Let's go through the other options and explain why they are not adverse effects of gentamicin:

A. Urinary frequency: Urinary frequency is not a common adverse effect of gentamicin. Gentamicin primarily affects the kidneys, and its main concern is related to potential nephrotoxicity (kidney damage) rather than causing urinary frequency.

B. Constipation: Constipation is not an adverse effect typically associated with gentamicin. Gentamicin is not known to affect the gastrointestinal system or cause constipation.

C. Hypertension: Hypertension (high blood pressure) is not a known adverse effect of gentamicin. Gentamicin primarily affects the kidneys and the inner ear, as mentioned earlier, but it does not significantly impact blood pressure.

Neostigmine is a medication classified as an acetylcholinesterase inhibitor. It is commonly used to treat myasthenia gravis and to reverse the effects of non-depolarizing neuromuscular blocking agents used during surgery. Adverse reactions to neostigmine are related to its cholinergic effects, which result from increased acetylcholine levels in the body.

Let's go through the options:

A. Hypoactive bowel sounds: Neostigmine can actually increase gastrointestinal motility and may cause increased bowel sounds or even diarrhea, not hypoactive bowel sounds. Therefore, hypoactive bowel sounds are not an adverse reaction to neostigmine.

B. Sweating: Sweating is a cholinergic effect and can be an adverse reaction to neostigmine. Increased sweating is a common sign of cholinergic stimulation.

C. Respiratory distress: Respiratory distress can occur as an adverse reaction to neostigmine, particularly if the client has a history of asthma or other respiratory conditions. Neostigmine can cause bronchoconstriction and excessive secretions, leading to respiratory distress.

D. Urinary retention: Neostigmine is actually used to treat urinary retention by increasing bladder contraction. Therefore, urinary retention is not an adverse reaction to neostigmine.

E. Bradycardia: Bradycardia (slow heart rate) is a significant adverse reaction to neostigmine due to its cholinergic effects on the heart. Increased acetylcholine levels can lead to excessive stimulation of the vagus nerve, resulting in bradycardia.