(A-156) Prescription and Non-Prescription Medication Use Before and After a Herpes Zoster Diagnosis Among Nursing Home Residents in the United States

Background: Herpes zoster (HZ) is a common and potentially debilitating condition in older and immunocompromised adults that is commonly managed with a combination of antivirals, steroids, and pain medications. Few studies have investigated the nature and extent of prescription and non-prescription medications among nursing home residents with HZ – a population at high risk of medication-associated adverse events and drug interactions.

Objectives: To characterize prescription and non-prescription medication administrations prior to and following an HZ diagnosis in nursing home residents.

Methods: We conducted a retrospective cohort study using community nursing home electronic health record data between 2017 and 2022. Diagnoses for HZ were identified using ICD-10 codes in the active diagnosis file. We identified all administrations of antivirals, steroids, pain medications (opioid and non-opioid), antibiotics, and gabapentinoids within 30 days of the HZ diagnosis date in periods of time (i.e., 1-7, 8-14, 15-30 days prior to diagnosis, and 1-7, 8-14, 15-30 days after diagnosis). To assess medication changes over time, each period was compared to 15-30 days prior to diagnosis (“baseline period”). Prevalence ratios (PRs) with the baseline period as a reference were used to summarize relative changes over time.

Results: We identified 4,697 residents with an HZ diagnosis (mean age=77 years; 69.5% female). Acetaminophen (20.9%), acetylsalicylic acid (13.9%), and gabapentin (13.4%) were the most prevalent medications administered during the baseline period. Antivirals showed the largest relative and absolute increases in administrations up to and following the HZ diagnosis date, peaking at 0-7 days after diagnosis (acyclovir: baseline=0.7%, 0-7 days after=28.1%, PR=40.1; valacyclovir: baseline=0.5%, 0-7 days after=23.7%, PR=44.7). Hydrocortisone (baseline=1.5%, 0-7 days after=4.8%, PR=3.2), gabapentin (baseline=13.4%, 0-7 days after=31.3%, PR=2.3), and oxycodone (baseline=1.2%, 0-7 days after=2.6%, PR=2.2) also showed larger relative changes over time. Antivirals, gabapentinoids, and hydromorphone remained elevated compared to the baseline period in the 15-30 days following diagnosis (PR > 1.5).

Conclusions: We documented increases in antivirals, steroids, gabapentinoids, and opioid pain medication use before and several weeks following HZ diagnoses among nursing home residents. Evidence supporting the use of gabapentinoids and opioids for prolonged periods following diagnosis requires future study and risk-benefit evaluation.