The following patients should not have this injection: if you are allergic to any of the medications to be injected, if you are on a blood-thinning medication (. Coumadin, injectable Heparin), or if you have an active infection going on. With blood thinners like Coumadin, your doctor may advise you to stop this for 4-7 days beforehand or take “bridge therapy” with Lovenox prior to the procedures. Anti-platelet drugs like Plavix may have to be stopped for 5-10 days prior to the procedure. Aspirin should be stopped for cervical procedures for 10 days prior, but not for Lumbar.