Clinical tolerance of
benzylpenicillin administered intramuscularly in doses of 2000000--3000000 units every 4--6hours (12000000 units a day) was studied in 253 patients with
pneumonia. Satisfactory tolerance of
sodium benzylpenicillin and pronounced painfulness at the site of injection of
potassium benzylpenicillin were noted. General toxic side effects in the form of
asthenia,
dizziness,
pain in the heart region were observed in a part of elderly patients. The
benzylpenicillin serum levels after administration of 2000000 units were 6--10 times higher than those after administration of 200000 units. The efficiency of
benzylpenicillin elevated doses was studied in 193 patients. In 101 of them the previous treatment with usual doses of
benzylpenicillin, i. e. 200000 units every 4 hours was not sufficiently effective. The elevated doses of
benzylpenicillin proved to be effective in 78 per cent of the cases, the effect being observed in all the cases with acute
pneumonia, in 88.5 per cent of the cases with neglected state and in 83 per cent of the cases with chronic
pneumonia. The
therapeutic effect was also observed in most of the patients with
benzylpenicillin resistant microflora in the sputum. On the basis of high efficiency of
penicillin therapy it was concluded that gram-positive cocci played the main role in
pneumonia etiology.