What is the guideline when choosing a drug from the group of non-steroidal inflammatory drugs?

It is impossible to predict which NSAID will be best tolerated by a particular patient; no particular NSAID has demonstrated superiority over others for pain relief. Once an NSAID has been selected, the dose should be increased until pain has been relieved or the maximal recommended dose has been achieved. The duration of analgesia does not always correlate with the serum half-life of the NSAID. Therefore, the response of the patient should guide the clinician in selecting dosing intervals of these agents. Because NSAIDs have ceiling effects to their efficacy, if a patient does not respond to the maximal dose of one NSAID, another should be tried before discontinuation of NSAID therapy. The use of NSAIDs has been associated with both minor (dyspepsia, heartburn, nausea, vomiting, anorexia, constipation, and abdominal pain) and major (bleeding, ulceration, and perforation) gastrointestinal toxicities. Hepatic and renal dysfunction or toxicity, which can occur at any time in the course of NSAID therapy, are of particular concern during long-term use. The initial choice of NSAID should be based on the efficacy and safety.