Q:

5/10/2013
Are there protocols for skin testing to linezolid?

A:

Thank you for your inquiry.

Unfortunately, I was not able to find any reference describing a specific protocol (concentration to use) for skin testing to linezolid. However, skin testing has been done to this drug at least once as evidenced by the link copied for you below to a website entitled ehealthme (labeled below as skin test to linezolid). In addition, there are two articles which present protocols for the desensitization to linezolid, but I have not seen in these articles a published protocol for skin testing itself. There is a link to the protocol for desensitization copied for you below as well. Finally, there is an abstract copied below describing desensitization to linezolid in the Journal of Pharmacotherapy.

However, as noted, I could not find a published protocol for skin testing per se. Nonetheless, if one looks at nonirritating concentrations of antibiotics generally employed for skin testing, dilutions varying from a 1 to 10 to 1 to 10,000 have been cited as being appropriate for intradermal testing (Empedrad, et al. Nonirritating intradermal skin test concentrations for commonly prescribed antibiotics. J Allergy Clin Immunol 2003; 112(3):629-630. I believe that you could therefore start with a 1 to 10,000 concentration, and progress to more concentrated solutions ending at a 1 to 100 concentration in the absence of a published protocol.

Thank you again for your inquiry and we hope this response is helpful to you.

Cawley MJ, Lipka O. Intravenous linezolid administered orally: a novel desensitization strategy. Pharmacotherapy. 2006 Apr;26(4):563-8.
Source
Department of Pharmacy Practice and Pharmacy Administration, Philadelphia College of Pharmacy, University of the Sciences in Philadelphia, Philadelphia, Pennsylvania 19104, USA
Abstract
A 41-year-old woman with a history of myasthenia gravis was admitted to a local hospital because of severe muscle weakness, ptosis, shortness of breath, nausea and vomiting, and fever. Blood cultures revealed Enterococcus faecium resistant to several antimicrobial agents. The organism had minimum inhibitory concentrations above 16 microg/ml for vancomycin and above 2 microg/ml for quinupristin-dalfopristin. In the absence of therapeutic alternatives, treatment with linezolid was required (minimum inhibitory concentration 1.5 microg/ml). The first dose of linezolid resulted in a hypersensitivity reaction consistent with an immunoglobulin E-mediated response requiring medical intervention. Because of a lack of intravenous access and because of limited availability of the oral suspension from the manufacturer, a desensitization protocol was implemented in which the intravenous formulation of linezolid was given orally. The patient was successfully desensitized by using an escalating, 14-dose procedure. We believe this is the first case in the English language literature to describe successful desensitization with the oral administration of intravenous linezolid in a patient with E. faecium bacteremia who was allergic to oxazolidinone.

Protocol for desensitization to linezolid

Skin test to linezolid

Sincerely,
Phil Lieberman, M.D.

 

AAAAI - American Academy of Allergy Asthma & Immunology