The nurse should teach a patient to observe which side effects when taking ampicillin.

A. Seizures: Some antibiotics, especially cephalosporins, can lower the seizure threshold, increasing the risk of seizures, especially in individuals prone to seizures or those with a history of epilepsy.

B. Nephrotoxicity: Both cephalosporins and aminoglycosides have the potential to harm the kidneys. When used together, their nephrotoxic effects can be additive, increasing the risk of kidney problems in patients.

C. Hearing Loss: Aminoglycosides, a class of antibiotics that includes drugs like gentamicin, are well-known for their potential to cause hearing loss, especially when used in high doses or for prolonged periods. This effect is due to their toxic impact on the hair cells in the inner ear.

D. Hepatotoxicity: Hepatotoxicity refers to liver damage caused by medications. Some antibiotics, including certain cephalosporins, can have hepatotoxic effects, potentially harming the liver. Monitoring liver function is important when these drugs are used.

A. Obtaining all cultures before the antibiotic is administered: While obtaining cultures is important for identifying the specific pathogen causing the infection and guiding targeted antibiotic therapy, waiting for culture results can take time. During this time, the infection can progress. Therefore, it's generally recommended to initiate broad-spectrum antibiotics first and then adjust the treatment based on culture results.

B. Delaying administration of the antibiotic until the culture results are available: Delaying antibiotics until culture results are available can be risky, as it allows the infection to progress, potentially leading to sepsis or other severe complications.

C. Administering antipyretics as soon as possible: Administering antipyretics like acetaminophen or ibuprofen can help reduce fever and make the patient more comfortable. However, the primary intervention for a suspected infection is antibiotic therapy, as it targets the underlying cause of the fever.

D. Administering the antibiotic immediately: When dealing with a patient with a fever of unknown origin and a suspected infection, the priority is to start appropriate antibiotic therapy promptly. Delaying antibiotic administration can allow the infection to worsen, leading to serious complications.