Demethylchlortetracycline and Tetracycline

Abstract

In September, 1959, a new tetracycline compound, demethylchlortetracycline^*(here-after referred to as DMCT), became available for general use. This compound is reported to be identical in structure to chlortetracycline except for the absence of a methyl group in the 6-position.¹In early studies it was found to be more resistant to acid and alkali degradation than the other tetracyclines in common use,¹and to be generally more active against bacterial pathogens than tetracycline (hereafter referred to as TC) or oxytetracycline.^2-5The amount of DMCT absorbed from the gastrointestinal tract of man following a single dose was less than with TC,^6,11but Kunin and Finland found that the serum half-life was 44% greater for DMCT than for TC, and the renal clearance of the former drug was only 43% of the latter.⁷Assays of serum antibacterial activity after equal doses of the 2 drugs showed significantly