“Ton Dulon”

I once took 3 weeks of Ancient Greek in high school. By take I mean I went, and though now I see and understand the influence that language had on our English language, I only remember two words. 

Ton dulon. I can’t find anything to back this up, but I remember our professor hunching his shoulders as he described ton dulon as the “slow, lumbering yoked oxen at work” and for the life of me I don’t know why that stuck with me. My only affinity for Greece is Greek food and beaches. But all that rambling was just to talk about the word oxen so I could transition flawlessly to oxacillin. The next antibiotic in my “list” (I don’t have that much organization). 

Oxacillin is a second generation penicillin. And we all remember how those work right? Beta-lactam rings and the destruction of the peptidoglycan of the cell wall? Of course you remember. But this is for me so I remember. Oxacillin is primarily used for Staph and Strep infections, especially those what produce beta-lactamase. This is great! Right? Nothing could go wrong…. Except antibiotic resistance of course! Oxacillin was first used against penicillin resistant S. aureus which has gradually built defenses against oxacillin and other antibiotics meant to bypass this resistance. MRSA and VISA are two acronyms you might recognize. This happens when a gene gets activated that stops the inactivation of cell wall production by beta-lactams. Is it more complicated? Yes. Am I smart enough to tell you how? Nope. This is not the biologist you are looking for. 

But I’m not here to opine on resistance. Since oxacillin is a narrow spectrum antibiotic, it is preferred when the offending organisms are susceptible. The smallest caliber round that still gets the job done. Remember however, penicillin allergies and history positive for CDAD. Oxacillin is also linked to renal and hepatic toxicity. Not uncommon precursors to infections. 

Side note. I’m trying hard to remember these things. A patient, severe obesity and recurrent UTIs, was on cephalexin 500mg qd. What the hell? Post op my doc gives at twice that. I asked a pharmacist and guess what, I knew the patient needed dialysis but didn’t connect the dots. It would stay in her system longer. I say that so I remember and to remind you how awesome pharmacists can be. 

It degrades the effectiveness of OCP, live typhoid vaccine,  and warfarin. Pregnancy category B with no shown harm to the fetus. Dosed IV at 1-2g q4-6h it can cost from $109 to $300 for a 10 day course. 

That’s my story and I’m sticking to it. Anyone have experience with the “ox”? Let me know facts, opinions, studies, and dogma about it. Peace out all. 

References 

Comprehensive Genomic Investigation of Adaptive Mutations Driving the Low-Level Oxacillin Resistance Phenotype in Staphylococcus aureus from Giulieri et al.  at the American Society for Microbiology 2020. 

Image of MRSA from Wikipedia and since my fiancé is a lab scientist we may or may not have something similar on our walls. 

Oxacillin from Antimicrobe.org. 

Oxacillin from the NIH: National Library of Medicine in Liver Tox updated 2023.