Nabumetone is a nonsteroidal anti-inflammatory drug (NSAID). Nabumetone was developed by Beecham and first received regulatory approval in 1991. It is available under numerous brand names, such as Relafen, Relifex, and Gambaran. Nabumetone is a nonacidic NSAID prodrug that is rapidly metabolized in the liver to the active metabolite, 6-methoxy-2-naphthyl acetic acid. As found with previous NSAIDs, nabumetones active metabolite inhibits the cyclooxygenase enzyme and preferentially blocks COX-2 activity (which is indirectly responsible for the production of inflammation and pain during arthritis). 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. Medical uses
Similar in action to other NSAIDs, Nabumetone is used to treat pain and inflammation.
They propose that aged basal cells contain lipofuscin bodies that cannot be removed and might promote the aging of neighboring cells, generating a feedback loop that causes more and more neighbor cells to become aged and contain lipofuscins. Such cells might then aggregate into a spot with an irregular shape. They propose that the protrusion of a flat spot is a result of the death of aged cells in the spot and release of lipofuscin bodies. The aggregating cells would form a capsule, and the dense lipofuscin bodies make the protruding spot soft and dark in color. However, this proposal appeared as a preprint in 2015, has little direct empirical support, and has never been published in a peer reviewed journal. Another group has reported that "age spots" taken from human skin biopsies of patients facial senile lentigo of Fitzpatrick skin type III or IV aged 55–62 are enriched with senescent fibroblasts compared to surrounding skin. The dark coloration appeared to be due to higher melanin levels and activity of tyrosinase in the senescent fibroblasts than in the controls, potentially related to lower SDF1 expression. Patients were then administered six weekly treatments of microneedle fractional radiofrequency aimed at eliminating dermal senescent fibroblasts; this led to a marked decrease in epidermal pigmentation compared to baseline, accompanied by a decrease in the synthesis of collagen and the normalization of suppressed SDF1 expression. Treatment
Treatment for liver spots is almost never done for health-related reasons, though it is sometimes done for aesthetic ones.