Nabumetone is a nonsteroidal anti-inflammatory drug. Nabumetone has been developed by Beecham. It is available under numerous brand names, such as Relafen, Relifex, and Gambaran. Nabumetone is a nonacidic NSAID that is rapidly metabolized in the liver to a major active metabolite, 6-methoxy-2-naphthyl acetic acid. As found with previous NSAIDs, nabumetone's active metabolite inhibits the cyclooxygenase enzyme and preferentially blocks COX-2 activity. The active metabolite of nabumetone is felt to be the compound primarily responsible for therapeutic effect. Comparatively, the parent drug is a poor inhibitor of COX-2 byproducts, particularly prostaglandins. It may be less nephrotoxic than indomethacin. There are two known polymorphs of the compound. Nabumetone has little effect on renal prostaglandin secretion and less of an association with heart failure than other traditional drugs of the class. Effects of nabumetone on blood pressure control in hypertensive patients on ACE inhibitors is also good—equivalent to paracetamol. As of 2015 the cost for a typical month of medication in the United States is 25 to US$50.
Medical uses
Similar in action to other NSAIDs, Nabumetone is used to treat pain and inflammation.
Side effects
It has been shown to have a slightly lower risk of gastrointestinal side effects than most other non-selective NSAIDs since it is a non-acidic prodrug which is then metabolized to its active 6MNA form. Side effects include: Bloody or black, tarry stools; change in color, frequency, or amount of urine; chest pain; shortness of breath; coughing up blood; pale stools; numbness; weakness; flu-like symptoms; leg pain; vision problems; speech problems; problems walking; weight gain; stomach pain; cold sweat; skin rash; blisters; headache; swelling; bleeding; bruising; vomiting blood; jaundice; diarrhea; constipation; dizziness; indigestion; gas; nausea; and ringing in the ears.
Assay of nabumetone
There are few papers published reporting analytical methods for nabumetone. Two of them employed HPLC with UV-detection. One HPLC method using direct injection on restricted access media columns. Flow injection analysis with UV-detection was also reported for the determination of nabumetone in pharmaceutical preparations. Methods using HPLC with fluorescence detection were reported. M. Nobilis et al. carried out biotransformation and disposition studies in humans and minipigs using HPLC with UV, fluorescence and mass spectrometric detection. The interactions with gamma-cyclodextrin were also studied by fluorescence measurements. Assay methods employed HPLC using UV detection, photodiode array detector and mass spectrometric detection for the determination of nabumetone and its metabolites. Murillo Pulgarín et al. reported three analytical methods using different techniques along with phosphorescence. Liquid chromatography methods using different techniques of mass spectrometry were also reported. The electrochemical behavior of nabumetone by a voltammetric technique and a novel colorimetric method based on chemical derivatization were also published. P. K. Sahu et al. has reported a HPLC method for simultaneous estimation of nabumetone and paracetamol in combined dosage form.
