The effect of food on bromfenac, naproxen sodium, and acetaminophen in postoperative pain after orthopedic surgery.

STUDY OBJECTIVES

To evaluate the effect of a standard meal on bioavailability of bromfenac, and on the relative analgesic efficacy and adverse effect liability of bromfenac 25 mg, naproxen sodium 550 mg, and acetaminophen 325 mg in the treatment of pain after orthopedic surgery.

DESIGN

Randomized, double-blind, single-dose, parallel-group.

SETTING

Two wards of the orthopedic surgery department at the Central Hospital, Karlstad, Sweden.

PATIENTS

Three hundred ten patients with steady, moderate, or severe pain within 72 hours after orthopedic surgery.

INTERVENTIONS

Patients were randomly assigned both to receive a standard meal or remain in a fasted state, and to treatment with a single oral dose of bromfenac 25 mg, naproxen sodium 550 mg, or acetaminophen 325 mg, when they experienced steady, moderate, or severe pain that required an analgesic. Using a self-rating record, subjects rated their pain and its relief for up to 8 hours after medicating. Blood samples were obtained from all patients using one of two schedules.

MEASUREMENTS AND MAIN RESULTS

The peak plasma bromfenac concentration for fed patients was only 28% of that of fasted patients. Disregarding food intake, bromfenac 25 mg and naproxen sodium 550 mg were significantly superior to acetaminophen 325 mg for all summary measures of analgesia. Bromfenac and naproxen were superior to acetaminophen by hour 1 and this difference persisted for 8 hours. Food reduced bromfenac's analgesic effect, but not that of naproxen or acetaminophen; treatment by meal interaction was significant for five measures of efficacy. Analgesic response for fed bromfenac recipients, compared with those who were fasted, ranged from 37-71%. The percentage of patients reporting an adverse effect was significantly higher for bromfenac (25%) and naproxen (24%) than for acetaminophen (12%).

CONCLUSIONS

Results of analgesic studies not taking patients' food status into consideration might be misleading. Although bromfenac 25 mg and naproxen sodium 550 mg produced significant analgesia compared with acetaminophen 325 mg, bromfenac's efficacy was significantly reduced when patients ate a standard meal. Adverse effects were transient and consistent with the pharmacologic profiles of the drugs.