I have a patient who reports that MSG causes severe cramping and diarrhea and that sucrose causes an itchy rash and trouble breathing. She would like a Zostavax immunization but Zostavax contains both MSG and sucrose. What advice should I give her?


Thank you for your inquiry.

Unfortunately, I do not have a “good answer” for you. Normally, in this type of circumstance, we would suggest a graded challenge procedure. For example, the dose of Zostavax is 0.65 ml, containing a minimum of 19,400 plaque-forming units. Utilizing most vaccines, we would suggest an initial dose of 0.1 ml followed up a day later by a dose of 0.1 to 0.2, and continuation of this graded challenge until the full dose was administered. The interval between dosing could be shortened, depending upon the potential nature of the adverse response. However, in regards to Zostavax, we have a difficult situation in that the instructions state that the drug must be administered immediately after reconstitution, and that it should be discarded within 30 minutes if not used. And, because the vaccine is so expensive, it would be impractical to reconstitute a new vial each time a graded challenge dose was administered.

Thus, in final analysis, since there is no way to test for the type of reaction you described, and since a graded dosage challenge would not be practical, one would simply have to decide whether or not the administration of the drug, in its full dose, was justified by an analysis of risk/benefit. Thus there is no easy answer to this conundrum. The only way to come to a conclusion would be to discuss the issues with your patient and, with their cooperation and understanding, make a decision as to whether or not to give the vaccine or simply not immunize her.

Thank you again for your inquiry and I am sorry that we could not come up with a better solution for you.

Phil Lieberman, M.D.

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