When there are few or no alternative medications with which to treat the infection, a doctor may recommend a procedure called antibiotic desensitization. This process takes place under extremely careful supervision in the intensive care unit (ICU) of the hospital. A patient is started on a very small dose of the antibiotic and watched carefully for any signs of allergic response. When the patient is observed to tolerate that dose, the pharmacist will prescribe a slightly higher concentration of the drug. Little by little, stronger concentrations of are delivered to the body until the full recommended treatment dose is achieved.
At this point, if the patient has exhibited no severe allergic reactions to the antibiotic, he or she is said to be successfully desensitized. From that point forward, that antibiotics should always be used first to treat infection so that the patient does not redevelop sensitivity to it.