Experimental Studies on Synergism Between Aminoglycosides and the Antimicrobial Antiinflammatory Agent Diclofenac Sodium

Abstract

The antiinflammatory agent diclofenac sodium (Dc) exhibited remarkable antibacterial effects both in vitro and in vivo. Fifteen different bacteria sensitive to Dc as well as to a number of common antibiotics were tested for synergistic effects in vitro. Disc diffusion test with Dc and aminoglycosides assessed by stringent computation showed clear-cut synergism. Synergism between Dc and streptomycin (Sm) was found to be statistically significant (p < or = 0.01) when compared with their individual effects. By the checkerboard assessment procedure, the fractional inhibitory concentration (FIC) index of this combination was found to be 0.49, confirming synergism. The mouse protective capacity of this combination was then evaluated in vivo against S. typhimurium as the virulent infecting bacterium, and the size of bacterial load determined from infected autopsied animals. Statistical analysis by Student's 't' test suggested this drug combination is highly synergistic; synergism was also noted between Dc and other aminoglycosides.

Antimycobacterial activity of the antiinflammatory agent diclofenac sodium, and its synergism with streptomycin

“…Table 5 shows that of the 10 animals in the untreated group, all developed minute tubercles in the liver, 5 in the spleen, 5 in the lungs and 9 in the peritoneum and intestines; microscopic necrosis suggestive of caseation was found in the liver of 3 animals and in the spleen, peritoneum and intestines each in one animal. Smears for acid-fast bacilli by Z-N stain, from centrifuged deposits (for 100 fields) of tissue homogenates, effects of Dc and Sm, as well as Dc and the non-antibiotic trifluoperazine on Gram positive and Gram negative bacteria provided significant synergism both through in vitro and in vivo experiments (4,11). In the present study, Dc has shown a remarkable antitubercular activity against a number of mycobacteria.…”

Evidence of significant synergism between antibiotics and the antipsychotic, antimicrobial drug flupenthixol

“…Nevertheless, although many new anti-infective compounds are reported in the literature, it is expected that the appearance of mutations and acquisition of drug-resistant plasmids will restrict their usage for therapy of infections [6,7]. However, several studies have revealed that significant antimicrobial actions are present in a large number of pharmacologically diverse categories of compounds designated as "non-antibiotics" [8][9][10][11][12][13][14][15][16][17][18][19][20]. Moreover, some of these "non-antibiotics" act synergistically with conventional antibiotics rendering initially antibioticresistant bacteria susceptible [16][17][18][19][20].…”

In Vitro and In Vivo Synergism between Tetracycline and the Cardiovascular Agent Oxyfedrine HCl against Common Bacterial Strains

“…Finally, the diameters of inhibition zones produced due to individual and mutual effects of two drugs were recorded on the same plate. The mutual influence/interference encountered when two drugs were used in combination was assessed as follows 15) : (i) indifference, when both the zones of inhibition remained unaffected; (ii) antagonism, when the zones of inhibition receded and assumed kidney shape; (iii) synergism, in which there was enlargement of zones. The statistical evaluation of the increase in surface area (pr 2 ) of a zone, if any, due to a combination of effects was done by the c 2 test for its level of significance.…”

“…14) Many of these non-antibiotic agents have further shown remarkable synergistic action with several antibiotics and other non-antibiotics. 15,16) The antianginal and coronary vasodilator oxyfedrine HCl (Oxy) was previously reported to be a non-antibiotic agent that demonstrated significant antimicrobial action. 17) This drug could inhibit bacteria in the following order: Staphylococcus aureus, vibrios, Bacillus spp., Shigella spp., Salmonella spp., Escherichia coli, Klebsiella spp.…”