Final answer:
Potential interactions of concern when a patient is receiving linezolid therapy include Selective Serotonin Reuptake Inhibitors (SSRIs), due to the increased risk of serotonin syndrome.
Step-by-step explanation:
The nurse concerned about a potential interaction with linezolid (Zyvox) therapy should be wary of any orders including Selective Serotonin Reuptake Inhibitor antidepressants (SSRIs). Linezolid acts as a weak monoamine oxidase inhibitor (MAOI), and concurrent use with drugs that affect the serotonergic system, such as SSRIs, can increase the risk of serotonin syndrome, which is a potentially life-threatening condition. Other medications highlighted, such as calcium channel blockers, phenytoin, or anticoagulants, do not have as significant an interaction risk with linezolid as the SSRIs do.