For which of the following drugs would peak levels be most critical to monitor?

Monitoring peak drug levels is particularly critical for aminoglycosides because these antibiotics have a narrow therapeutic index, meaning that the difference between an effective dose and a toxic dose is small. Elevated peak levels of aminoglycosides can lead to significant toxicity, particularly renal damage and ototoxicity.

These drugs require careful dosing and frequent monitoring to ensure that drug concentrations within the body remain in the therapeutic range. Collecting peak levels, which are taken after the drug is administered and absorbed to assess the highest concentration of the drug in the bloodstream, is fundamental in achieving optimal therapeutic outcomes while minimizing the risk of toxicity.

For other categories of drugs mentioned, their therapeutic windows and monitoring requirements do not necessitate the same level of scrutiny for peak levels. For example, barbiturates may require monitoring, but not necessarily for peaks, while stimulants and antidepressants generally have more flexible therapeutic ranges that do not yield immediate and serious adverse effects if peak levels fluctuate.