Penicillin dosage in the blood and investigation in cerebrospinal fluid from patients with neurolues treated with procaine penicillin or benzathine penicillin G

Abstract

The variation of temperature caused by the constant employment of a common refrigerator does not change, considerably levels in blood samples stored up to 76 hours.

Blood samples maintained at room temperature during 40 minutes did not show significative decrease in the penicillin levels. Dosages of penicillin in the blood and research in the liquor were made in order to verify if in the neuroluetics the classical scheme of treatment of 50,000 to 100,000 i.u. of crystalline penicillin G, by intramuscular route, every three hours, could be substituted by a more practical and economical administration of procaine penicillin G, in the 24-hour dose of 300,000 to 600,000 i.u. 300,000 i.u. of procaine penicillin were given intramuscularly, to two patients, every 24 hours. In 26 dosages made 24 hours after each injection, penicillin was found only three times, the titer having been 0.06 u. per ml. No penicillin was present in seven samples of subcoccipital liquor taken 24 hours after each injection, 300,000 u. of procaine penicillin G were given to three patients, every 12 hours. In 38 dos ages made in blood serum 12 hours after each injection the titers mean of penicillin was 0.223 u. per ml ± 0.117; (0.06 u. per ml being the lowest value found (four times) and the highest 0,64 i.u. (once). In 23 tests of penicillin in the liquor made 12 hours after each injection the result was always negative. 600,000 u. of procaine penicillin G were given to two patients every 24 hours. In 30 dosages made 24 hours after each injection the titers mean of serum penicillin was 0.031 u. per ml ± 0.039, 17 determinations having been negative. Nine tests of penicillin in liquor, 24 hours after each injection, were negative. 50,000 i. u. of crystalline penicillin G were administered intramuscularly to five patients, every three hours. In 38 dosages made 3 hours after each injection the titers mean of serum penicillin was 0.071 u. per ml ± 0.033. In 43 determinations of penicillin in the liquor made 3 hours after the injection all the results were negative. The blood levels of penicillin stay higher by the use of small amounts of the solvent. 100,000 i. u. of crystalline penicillin G were given to two patients, intramuscularly, every 3 hours. In 19 dosages made 3 hours after each injection the titers mean of penicillin was 0.121 u. per ml ± 0.087. Sixteen tests of penicillin made in liquor, 3 hours after the injection, were negative. No penicillin was found in the liquor of two patients administered with 600,000 i.u. of procaine penicillin G, when determined from 2 to 7 hours after the injection. No penicillin was found in the liquor of 2 patients to whom 100,000 i.u. of crystalline penicillin G were injected either intramuscularly or intravenously, when determined from 15 minutes to 5 hours after the administration of the antibiotic. The blood levels of crystalline or procaine penicillin were not influenced by the long period of the treatment, thus showing that there is neither accumulative effect of the antibiotic nor increase of the capacity of elimination of the drug. In several patients treated with the same therapy the variability of penicillin levels blood is explained by interference of lying in bed, quantity of liquids administered, vascularization of the injected region and renal permeability. From these proved schemes, the one which showed higher and more uniform serum titers, at the end of each period of administration. Was that one of 300,000 i.u. of procaine penicillin G, every 12 hours. In the same conditions, the scheme of 600,000 i.u. of procaine penicillin G, every 24 hours, showed inferior titers of penicillin to those of 100,000 and 50,000 i.u. of crystalline penicillin G, by intramuscular route, every 3 hours.