To the Editor: In whatever way it acts, indomethacin has shown itself, in certain conditions, to be an excellent "anti-inflammatory" agent. To my knowledge, its use as an immediate and total "pain killer" is not generally known.For the past two years I have used this drug as the mainstay of analgesic therapy with unqualified success in each case of acute pleurisy or pericarditis (or both), regardless of etiology. As a background, I, like most physicians, had repeatedly witnessed futile attempts to control the exquisite pain produced by inflammation of the cavity tissues. The only absolute achievement of the usual . . .