Demethylchlortetracycline Therapy in Pneumonia, Scarlet Fever, and Other Infections

Demethylchlortetracycline (DMCT),* a new antibiotic, is produced by a mutant strain of Streptomyces aureofaciens.¹ Three laboratories have demonstrated that significant antibacterial activity is found in the serum as a result of oral administration of this drug.^2-4 Each of these groups of investigators has shown that this antibiotic is more effective than its analogue, tetracycline, when equal amounts of the two antibiotics are tested against the common laboratory assay organisms Bacillus cereus #5, Streptococcus 98, or Staphylococcus 209P. In addition, many strains of Staphylococcus aureus organisms isolated from infected patients share this increased sensitivity.⁴ DMCT is somewhat less effective in vitro than chlortetracycline. Comparable antibacterial activity in the serum is achieved with a lower dosage regimen of DMCT than of tetracycline or chlortetracycline because DMCT has a slower rate of renal clearance than the other two compounds.² The effects of three dosage regimens on the resulting serum levels of antibacterial activity