I saw a 21 year old man with MSSA lumbar discitis and osteomyelitis who is on cefazolin 2 grams Q12H. I would like your advice on changes to current therapy and on duration.
Spinal osteomyelitis is a serious and difficult condition to manage. An Infectious Diseases consult is highly recommended because individualization of therapy is usually necessary. All patients need to be evaluated radiologically to determine necessity for surgical drainage and a neurosurgical consult is often indicated.
In terms of antibiotic selection for serious MSSA infections cloxacillin and cefazolin are both good choices. Cefazolin is somewhat easier to administer as standard dosing is Q8H versus at least Q6H for cloxacillin. Cefazolin is much less venotoxic as well. In this man’s case his dose should be immediately increased to 2 grams Q8H.
He is a candidate for home IV therapy when he is stable and cefazolin at the same dose should be continued for a minimum of 6 weeks. Absolute duration of therapy must be determined by clinical and radiological progress.