Adherence to proton pump inhibitors or H2‐receptor antagonists during the use of non‐steroidal anti‐inflammatory drugs

Abstract

The efficacy of proton pump inhibitors (PPIs) or histamine-2 receptor antagonists (H2RAs) prescribed as prophylaxis for NSAID-related upper gastrointestinal (UGI) toxicity is dependent upon patient adherence. To describe patient adherence to prophylactically prescribed PPIs and H2RAs in the clinical setting. We conducted a retrospective observational cohort study using the Integrated Primary Care Information Project database. The study population consisted of incident non-specific NSAID users prescribed a PPI or H2RA specifically as prophylaxis for NSAID-related UGI toxicity. Patients were classified as non-adherent if < 75% of days of NSAID use were covered by one of these agents, and as continuing users after discontinuation of NSAID use if they had a renewed prescription for these agents after their last NSAID prescription. The study cohort comprised 784 patients: 374 with H2RAs, 405 with PPIs, and 5 with both PPI and H2RA. Eighty-five percent of H2RA users and 7% of PPI users were prescribed these drugs at doses below the minimum recommended/effective dose for NSAID-associated gastroduodenal ulcer prophylaxis. Thirty-seven percent of patients were non-adherent. The lowest rate of non-adherence was associated with the first NSAID prescription (9%), increasing to 61% for patients with >/= 3 prescriptions. In a cohort of subjects who stopped their NSAID and were followed for up to 2 years (n = 711), there was significant persistent use of acid suppressive agents; 40% of patients had at least one additional prescription for the acid suppressive agent after stopping NSAIDs, and> 30% received enough drug to cover a period longer than 2 months after stopping their NSAID. The pattern of PPI and H2RA prescriptions, when prescribed as prophylactic strategy, does not correspond with the pattern of NSAID use. Physicians should consider the medical impact of non-adherence with dual therapies and the impact of prolonged use of GPAs on treatment cost.