How can the nurse best determine treatment effectiveness in an older adult taking gemfibrozil?

Determining the effectiveness of gemfibrozil in an older adult primarily revolves around evaluating its impact on lipid levels, specifically triglycerides. Gemfibrozil is a medication that primarily lowers triglyceride levels and can also increase high-density lipoprotein (HDL) cholesterol. Therefore, a decrease in triglyceride levels is a direct indicator of how well the medication is working.

Monitoring liver enzymes could provide some information about potential side effects or complications of treatment, but it does not directly measure the efficacy of gemfibrozil in lowering triglyceride levels. Signs of gastrointestinal distress are relevant for assessing the side effects of the medication rather than its effectiveness. Increased energy levels, while potentially a beneficial effect of improved lipid profiles, are not a direct measurement of the drug's action. Thus, tracking triglyceride levels is the most objective and relevant way to assess how well the treatment is performing for the patient.