Effect of sodium diclofenac on serum and tissue concentration of amoxicillin and on staphylococcal infection.
The effect of sodium diclofenac on serum and tissue amoxicillin concentration as well as their effect against staphylococcal infection was observed. Four polyurethane sponges were placed in the back of thirty rats. After 14 d, two granulomatous tissues received 0.5 ml of 10(8) cfu/ml (Staphylococcus aureus). Two days later, the rats were divided into five groups: group 1 received amoxicillin 50 mg/kg/p.o., group 2 received amoxicillin 25 mg/kg/p.o., group 3 received sodium diclofenac 2.5 mg/kg/i.m. and amoxicillin 50 mg/kg/p.o., group 4 received sodium diclofenac 2.5 mg/kg/i.m., and group 5 (control group) received NaCl 1 ml/p.o. After six hours of drug administration, blood serum (10 microl) and noninfected granulomatous tissues were placed on Mueller-Hinton agar inoculated with 10(8) cfu/ml (S. aureus). Infected tissues were dispersed in a sonic system and were spread (10 microl) on salt mannitol agar. Microorganisms were counted and the inhibition zones were measured after 18 h of incubation at 37 degrees C. Amoxicillin tissue concentration was 6.27 microg/g for group 1, 2.18 microg/g for group 2, and 0.72 microg/g for group 3. The serum concentrations were 11.56 microg/ml for group 1, 5.36 microg/ml for group 2, and 1.34 microg/ml for group 3. No differences were observed among group 1, 2, and 3 regarding staphylococci counts (Kruskall-Wallis test p>0.05). Group 4 reduced (p<0.05) staphylococci counts comparing to group 5. It was concluded that sodium diclofenac reduced serum and tissue amoxicillin concentration and, even in large doses, amoxicillin was not effective in eradicating the staphylococcal infection after 6 h of administration.
Groppo
Francisco Carlos
FC
Department of Pharmacology, Anaesthesiology and Therapeutics-Piracicaba Dentistry School, Campinas State University, Av. Limeira 901, Bairro Areiao, Piracicaba, São Paulo, Brazil. fcgroppo@fop.unicamp.br
Simões
Roberta Pessoa
RP
Ramacciato
Juliana Cama
JC
Rehder
Vera
V
de Andrade
Eduardo Dias
ED
Mattos-Filho
Thales Rocha
TR
D000658:Amoxicillin / Q000493:pharmacokinetics* / Q000494:pharmacology; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D004008:Diclofenac / Q000494:pharmacology*; D004347:Drug Interactions; D006099:Granuloma / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology; D008297:Male; D008826:Microbial Sensitivity Tests; D010406:Penicillins / Q000493:pharmacokinetics* / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D013211:Staphylococcus aureus / Q000187:drug effects
D000894:Anti-Inflammatory Agents, Non-Steroidal; D010406:Penicillins; D004008:Diclofenac; D000658:Amoxicillin