Thesis (M.Sc. in Pharm.)--Chulalongkorn University, 2001

Background Nonsteroidal anti-inflammatory drugs (NSAIDs) use is known as a cause of upper gastrointestinal bleeding (UGIB). Risk factors of UGIB in NSAID users are age, a history of dyspepsia, peptic ulcer, and UGIB, multiple NSAID use, concomitant corticosteroids or warfarin therapy, high dose of NSAID use, and H. pylori infection. The purpose of this study was to predict the risk of GI bleeding in NSAID users. Patients and Methods The patients of this case-control study were NSAID users who use NSAIDs for at least 3 days and were gastroscoped at King Chulalongkorn Memorial Hospital. The patients with history of gastrointestinal varices, gastrointestinal cancer, chronic renal failure, and coagulopathy were excluded from this study. The data was collected from July 2001 to January 2002 by patient interviewing and charts reviewing. H. pylori status was assessed by rapid urease test or serology test. One hundred fifty four NSAID users were identified (89 were in UGIB group, 65 were in non-bleeding group). An equation for prediction of the probability of UGIB in NSAID users was generated by using enter logistic regression. Results Most of the patients were elderly (Mean age+-SD: 60.9+-12.6 years). 46.1% were men, and 53.9% were women. Age and the number of current NSAID users were statistically significant higher in patients with UGIB than non-bleeding patients ( p < 0.05, p < 0.01, respectively). The number of antiulceration drug users were statistically significant higher in non-bleeding patients than patients with UGIB (p < 0.01). The best model of predicted the risk of UGIB event in NSAID users was logit (UGIB) = 0.334-0.000048Age-8.53Sex+0.118(AgexSex)+0.344Current NSAID use+2.087Multiple NSAID use+1.429H. pylori infection-2.406Antiulceration drugs. The model had 99.9 of 2 log likelihood and 80.2% of the overall rate of correct classification. The probability of UGIB = elogit(UGIB) /1+elogit(UGIB). If the value of the probability of UGIB is more than 0.5, the patients have a high risk of UGIB. Conclusion Multiple NSAID use is the strongest factor that impacted on the probability of UGIB in NSAID users following by H. pylori infection. Antiulceration drugs usage reduced the risk of UGIB in NSAID users. A table demonstrated probability of UGIB in various groups of patients was developed. This table can be use as a guide for pharmacotherapy planning in clinical practices.