Oral tetracycline phosphate complex (Tetrex) in the treatment of non-specific urethritis.

The role of the tetracyclines is well established in the treatment of non-specific urethritis (NSU). This paper reports a ttrial of orally-administered tetracycline phosphate complex (Tetrex), a combination of acidified sodium hexametaphosphate with acidified tetracycline hydrochloride in the ratio of 3:1. This preparation is said to be absorbed from the alimentary tract more efficiently than the hydrochloride combination and to give blood concentrations twice as high (Shidlovsky, Prigot, Maynard, Felix, and Hjelt-Harvey, 1958). These properties, it is claimed, give the phosphate complex an advantage over other tetracycline analogues in that effective blood levels can be maintained with a 12-hour dosage regimen (Olon and Holvey, 1968). The promised advantages of ease of administration and convenience to the patient, together with the experience of one of us (Statham and Morton, 1968) in the use of Tetrex PMT, a parenteral preparation of rolitetracycline nitrate, led us to believe that a trial of oral tetracycline phosphate complex should be undertaken.