Negative effect of non-steroidal anti-inflammatory drugs on the antibacterial activity of ciprofloxacin - an in vitro study

Abstract

Ciprofloxacin, a second generation fluoroquinolone is often co-administered with non-steroidal anti-inflammatory drugs (NSAIDs) in life threatening situations in which Staphylococcus aureus infections are accompanied with pain and inflammation. This study was carried out to investigate possible in vitro interactions in co -administration of ciprofloxacin and some NSAIDs. The study was carried out in the Department of Pharmaceutical Microbiology, Faculty of Pharmacy, and University of Benin, Benin City in 2013. The in vitro evaluation was carried out by incorporating appropriate concentrations of the NSAIDs with ciprofloxacin in 20 ml final volume of Muller Hinton broth in the presence of Staphylococcus aureus and incubated at 37°C in a hot water-bath. Aliquots of 0.1 ml were removed every two hours; serially diluted and plated out on Mannitol Salt agar and incubated at 37oC for 24 hours. The number of colony-forming units (CFU) of Staphylococcus aureus was noted. It was observed that all the NSAIDs reduced the antibacterial activity of ciprofloxacin against Staphylococcus aureus in vitro to varying degrees. The highest reduction was exhibited by acetyl salicylic acid (ASA) as it yielded the highest number of CFU. This was followed closely by piroxicam, then indomethacin and lastly paracetamol (130 cfu; 65 cfu; 43 cfu; and 33 cfu.) respectively. There is a suggestion that the studied NSAIDs and perhaps NSAIDs generally should not be co-administered with ciprofloxacin at the same time. Keywords: Ciprofloxacin; NSAIDs; Interaction