- Willingness to refrain from use of aspirin, Ibuprofen, Naproxen or any other non-steroidal anti-inflammatory drug (NSAID) prior to study treatment and chronic use during the entire post-treatment study period. Washout period, if chronic user, for 4 weeks prior to the study treatment. After study treatment is completed, limited acute NSAID use, i.e., a maximum of 2-3 doses in any 2 week period, is allowed if needed.