416 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1952 



aureomycin. The more rapid disappearance of chloramphenicol from 

 the blood may be explained by the fact that it is more rapidly metab- 

 olized into the inactive nitro compound. In spite of this, however, in 

 some subjects chloramphenicol can be demonstrated in low concen- 

 trations at the twenty-fourth hour. In the therapeutic use of the 

 drug, proper dosages at intervals of 6 to 8 hours have been shown to 

 be clinically effective. As with single doses, the blood concentrations 

 obtained are much higher than those obtained with comparable oral 

 doses of aureomycin and terramycin. 



TERRAMYCIN 



The first report on terramycin, the third of the broad-spectrum 

 antibiotics to be isolated, gave an indication of its wide clinical possi- 

 bilities. This drug has an acute and chronic toxicity comparable to 

 the other broad-spectrum antibiotics. Although daily intramuscular 

 injections of the drug were well tolerated by dogs for a period of 2 

 months or more, it was indicated that intramuscular use of the drug 

 would probably cause local irritation. In high doses (75 to 225 mg. 

 per kg.) sodium terramycin in dogs resulted in impaired renal and 

 liver functions. Dogs dying from these large intramuscular doses 

 of sodium terramycin showed cloudy swelling of the liver and fatty 

 metamorphosis of the kidneys. 



Terramycin, as the hydrochloride, is administered largely in cap- 

 sule form by the oral route. Patients treated by this mode of adminis- 

 tration rarely show untoward reactions although there is evidence 

 that terramycin causes gastrointestinal irritation in some patients. 

 This is manifested by nausea, vomiting, and diarrhea. This is usually 

 minor in character. The nausea and vomiting can be controlled by 

 giving the capsules with milk. The use of milk does not interfere 

 with the absorption of terramycin; however, the use of aluminum 

 hydroxide gel is contraindicated as it is with aureomycin. Other 

 reactions reported include proctitis, vaginitis, and pruritis, usually 

 of a mild degree. 



Terramycin is now available for intravenous administration. This 

 preparation, however, should not be used except in those patients who, 

 for one reason or another, are unable to take the drug by mouth. The 

 relatively high alkalinity of the preparation may cause phlebitis on 

 intravenous administration and patients receiving this type of medi- 

 cation should be given the drug by the oral route as promptly as pos- 

 sible. The low toxicity of terramycin by mouth is evident from the 

 fact that doses of at least 15 grams per day over a period of 10 to 15 

 days have been given without evidences of serious toxic effects. 



Absorption and excretion. — The close relationship between ter- 

 ramycin and aureomycin is readily demonstrable in the absorption and 



