A client who takes sertraline has a new prescription for intravenous linezolid. Which action should the nurse take before administering the first dose?

Linezolid can interact with serotonergic antidepressants such as sertraline and cause serotonin syndrome. The nurse should pause administration and obtain a coordinated risk-benefit and medication plan rather than independently stopping long-term therapy or giving both medications without clarification.

Quick answer
Pause and clarify the linezolid-sertraline interaction before the first dose. The combination requires deliberate prescriber and pharmacy review.

Why this is correct
Linezolid has monoamine oxidase-inhibiting activity, and concurrent serotonergic drugs can produce dangerous agitation, hyperthermia, rigidity, myoclonus, and autonomic instability. Urgent linezolid use may still be justified, but the medication plan and monitoring must be coordinated.

Easy analogy or mental picture
The two drugs are like separate controls that can both raise pressure in the same system. Before turning on the second control, the team checks whether the system can be managed safely; this analogy does not mean the drugs have identical mechanisms or that linezolid is never appropriate.

Memory hook
Linezolid plus a serotonergic drug means stop before the dose, clarify the plan, then monitor deliberately.

NCLEX decision rule
When a new medication has a serious interaction with an active home drug, hold the pending dose long enough to clarify the order. Do not independently discontinue chronic therapy, mask the risk with premedication, or administer first and investigate later.

Why the other choices are wrong
Temperature monitoring alone does not prevent the interaction. The nurse should not independently stop sertraline, and diphenhydramine does not prevent serotonin syndrome.