- Chronic use of non-protocol approved non-steroidal anti-inflammatory drugs (NSAIDs), defined as greater than 3 to 4 times/month. The following NSAIDs are allowed: acetylsalicylic acid, etodolac, ibuprofen, indomethicin, ketoprofen, nabumetone, naproxen, nimesulide, piroxicam, and sulindac.