Copyright @ 2010 American Association of Neuroscience Nurses. Unauthorized reproduction of this article is prohibited. Effect of Oral Antihistamine on Local Injection Site Reactions With Self-Administered Glatiramer Acetate Gabriel Pardo, Christine Boutwell, Jill Conner, Douglas Denney, MerriKay Oleen-Burkey ABSTRACT Patients with multiple sclerosis often use injectable medication such as glatiramer acetate or interferons to treat their disease. Subcutaneous injections may be associated with local injection site reactions (LISRs), which can include itching, pain, swelling, or redness. Although not serious, these side effects are bothersome and can have a negative impact on adherence to the therapeutic regimen, particularly in early phases of treatment. This randomized parallel group study of 83 patients with multiple sclerosis who had recently begun glatiramer acetate therapy investigated whether administration of an oral antihistamine (cetirizine hydrochloride; Zyrtec, 10 mg) prior to each daily subcutaneous injection of glatiramer acetate would lower the incidence of LISRs compared with an oral placebo. Data for the outcome measures were derived from patient diaries and from the clinic during the baseline and the treatment periods. The primary outcome measure comparing the number of LISRs at 5 minutes after injection over 2 weeks was slightly but not significantly lower in patients who received cetirizine compared with patients who received placebo. Within-group comparisons showed that there was a significant reduction in mean LISR score from the 2-week baseline period to the 2-week cetirizine treatment period (0, 2, and 5 minutes after treatment). Both groups showed decreases in the average bothersome ratings from the baseline to treatment periods. Use of cetirizine did not affect the type of LISRs that was reported at any time point. There were no safety concerns with the concurrent administration of cetirizine with glatiramer acetate. Because there were no statistically significant differences on the primary end point between patient groups taking cetirizine and those taking placebo prior to glatiramer acetate injections, cetirizine use as a strategy to reduce LISRs in patients on glatiramer acetate therapy cannot be recommended at this time. S ix drugs have been approved by the U.S. Food and Drug Administration for treatment of mul- tiple sclerosis (MS), all of which are given by subcutaneous (SC) or intramuscular injection or intra- venous infusion. Local injection site reactions (LISRs) are not uncommon following SC injection and may contribute to nonadherence, particularly early in treat- ment (Frohman et al., 2004; Galetta & Markowitz, 2005; Jolly et al., 2008; Wingerchuk, 2006). Glatiramer acetate (Copaxone) is an immunomodulatory agent that is approved by the Food and Drug Administra- tion for the reduction of relapses in patients with relapsing-remitting MS (Johnson et al., 1995). The mechanism of action of glatiramer acetate is believed to involve immunomodulatory activity on monocytes, the development of anti-inflammatory T H 2 polarized CD4 T cells, increased production of neurotrophic factors, and restoration of deficiencies in CD4 + CD25 + Foxp3 + regulatory T-cells (Weber, Hohlfeld, & Zamvil, 2007). Glatiramer acetate has a favorable safety profile and is generally well tolerated. The most common adverse effects are LISRs (Johnson et al., 1995), which can be troublesome for some patients self-injecting glatiramer acetate (SC), par- ticularly those early in treatment who may be vulnerable to discontinuation (Jolly et al., 2008). The current program of research is aimed at pro- viding evidence-based guidance to physicians and nurses who are advising patients with bothersome LISRs to use glatiramer acetate. Such information could potentially improve patients’ adherence to the medication. Major types of LISRs observed for more than 350 patients taking glatiramer acetate in previous studies fell into the following categories: reddened, warm to touch, painful, raised area around the injec- tion site, trace of blood, and bubble at the injection site (Table 1; Jolly et al., 2008). Data compiled by Teva Neuroscience through its Shared Solutions patient support program shows that the first 60Y90 days after Journal of Neuroscience Nursing 40 Gabriel Pardo, MD MS, is the director of the MS Center of Oklahoma, Mercy’s NeuroScience Institute, Oklahoma City, OK. Christine Boutwell, MD, is a neurologist in Kansas City, MO. Jill Conner, PhD, is the director of Medical Operations at Teva Neuroscience, Kansas City, MO. Douglas Denney, PhD, is a professor of psychology at the University of Kansas, Lawrence, KS. Question or comments about this article may be directed to MerriKay Oleen-Burkey, PhD, at merrikay.oleenburkey@ tevaneuro.com. She is the director of Outcomes Research, Teva Neuroscience, Kansas City, MO. Copyright B 2010 American Association of Neuroscience Nurses