The rate of systemic reactions to immunotherapy injections is the same whether or not the dose is reduced after a local reaction

Background: Even though no studies have shown that local reactions to immunotherapy injections predict subsequent systemic reactions, many protocols continue to call for dose adjustments after local reactions. Objective: To determine whether the rate of systemic reactions to immunotherapy injections is affected by dose adjustment after local reactions. Methods: In our clinic before March 1999, if a patient had a local reaction to an immunotherapy injection, an adjustment was made to repeat or reduce the next dose. From March 1999 on, no such adjustments were made. At our outlying clinics, the adjustment protocol continued. A retrospective review was conducted for shots given from March 1997 to February 2001, recording whether an immunotherapy visit resulted in a systemic reaction. Results: In our clinic, there were 3,250 shot visits from March 1997 to February 1999 (adjustment protocol) and 4,692 visits from March 1999 to February 2001 (no adjustment protocol). The systemic reaction rate during the 2 periods was not different (1.11% vs 0.85%, P =.29). In the outlying clinics, there were 1,138 shot visits from March 1999 to February 2001 (adjustment protocol), and the systemic reaction rate was not different than in our clinic (no adjustment protocol) (0.88% vs 0.85%, P =.86). Conclusions: The rate of systemic reactions to immunotherapy injections is the same whether or not the dose is adjusted after a local reaction. These dose adjustments are thus unnecessary, and eliminating them lessens chances for errors and decreases the number of shots required to reach a therapeutic dose.