Medications to Treat Mast Cell DiseasesALL PATIENTS:Self-Injectable Epinephrine (two doses; e.g., EpiPen®/EpiPen Jr®) should be carried by all patients with a mast cell disorder at all times, even if previous anaphylaxis has not occurred. Both the patient and family members/caregivers should be trained on administering the epinephrine!Please visit the American Academy of Allergy, Asthma and Immunology (AAAAI) website for more information on anaphylaxis.Basic Medications for Symptomatic Patients with Mast Cell Diseases1-4H1 antihistamines: help with itching, abdominal pain, flushing, headaches, brain fogH2 antihistamines: help with gastrointestinal symptoms and overall mast cell stability (all mast cell activation symptoms)Mast cell stabilizers: help with stomach and intestinal symptoms and brain fogLeukotriene inhibitors: help with respiratory symptoms and overall mast cell stability (all mast cell activation symptoms)Aspirin therapy (under direct supervision of a physician): if tolerated and if prostaglandins are elevated, helps with flushing, brain fog and bone painNote: The H1 and H2 antihistamines are necessary to stabilize receptors on the mast cell. Therefore, if additional medication is required for control of gastroesophageal reflux (GERD), a proton pump inhibitor may be added to this protocol, but it cannot replace the H2 antihistamine.Please see Tables 1-6 for lists of some specific drugs in these different categories.Please see Table 7 for a list of some specific drugs for advanced systemic mastocytosis.Table 1. Some First Generation H1 AntihistaminesBrand NameGeneric NameAtarax®Hydroxyzine hydrochlorideBenadryl®DiphenhydramineChlortrimeton®ChlorpheniramineDoxepin®, Sinequan®Doxepin hydrochlorideTavist®ClemastineTable 2. Some Second Generation H1 Antihistamines (may tend to cause less drowsiness)Brand NameGeneric NameAllegra®FexofenadineClaritin®LoratidineClarinex®DesloratidineZaditor®/Zaditen® (in Europe)*KetotifenXyzal®LevocetirizineZyrtec®Cetirizine*Zaditor® is only available in the US as eye drops; Zaditen® is available by prescription, but it must be obtained from a compounding pharmacy or from abroad.Table 3. Some H2 AntihistaminesBrand NameGeneric NameAxid®NizatidinePepcid®FamotidineTagament®CimetidineZantac®RanitidineTable 4. Some Leukotriene InhibitorsBrand NameGeneric NameSingulair®MontelukastAccolate®ZafirlukastZyflo®/Zyflo CR®ZileutonTable 5. Mast Cell StabilizersBrand NameGeneric NameGastrocrom®Oral cromolyn sodiumZaditor®/Zaditen® (in Europe)*KetotifenAlgonot, Neuroprotect, etc.Food supplements containing bioflavonoids such as quercetin and luteolinBayer aspirin; Aspirin; ASAAspirin, acetylsalicylic acid (for those with high prostaglandin levels; aspirin therapy must be initiated under the direct supervision of a physician!)* Zaditor® is only available in the US as eye drops; Zaditen® is available by prescription, but it must be obtained from a compounding pharmacy or from abroad.Table 6. Proton Pump Inhibitors to Help with GERD (Gastroesophageal Reflux)Brand NameGeneric NameAciphex®RabeprazoleDexilant®DexlansoprazoleNexium®EsomeprazolePrevacid®LansoprazolePrilosec®OmeprazoleProtonix®PantoprazoleTable 7. Targeted Therapies/ Small Molecule Inhibitors may be prescribed for Selected Patients with Smoldering and Advanced Variants of Systemic Mastocytosis1, 5Brand NameGeneric NameAyvakit®Avapritinib (for ASM and ISM)Gleevec®ImatinibMasivet®MasitinibRydapt® (Midostaurin)PKC 412Sprycel®DasatinibTasigna®NilotinibThese medications are designed to inhibit the specific protein that control cells growing and dividing. This differs from conventional, classical chemotherapy that works by destroying rapidly growing and dividing cells.Table 8. Conventional Chemotherapy that may be prescribed for Selected Patients with Smoldering and Advanced Variants of Systemic Mastocytosis1, 5Brand NameGeneric NameHydrea®HydroxyureaLeustatin®, Leustat®, Litak®Cladribine, 2-CDATable 9. Immunotherapy that may be prescribed for Selected Patients with Smoldering and Advanced Variants of Systemic Mastocytosis1, 5Brand NameGeneric NameIntron®Interferon Alfa-2bThere are several more therapies in the pipeline, including additional tyrosine kinase inhibitors and other targeted therapies.Sometimes symptoms change, and it becomes necessary to increase or decrease doses of medications, or to add additional medications to a patient’s prescribed protocol. The simplest change made in conjunction with your mast cell specialist can make such a difference in your symptoms! Although it is tempting to change dosing regimens on your own, please always work with your physician to achieve the safest, most effective outcome! References Pardanani A. Systemic mastocytosis in adults: 2015 update on diagnosis, risk stratification, and management. Am J Hematol. 2015 Mar;90(3):250-62. http://www.ncbi.nlm.nih.gov/pubmed/25688753Theoharides TC, Valent P, Akin C. Mast Cells, Mastocytosis, and Related Disorders. N Engl J Med. 2015 Jul 9;373(2):163-72. http://www.ncbi.nlm.nih.gov/pubmed/26154789Akin C. Mast cell activation disorders. J Allergy Clin Immunol Pract. 2014 May-Jun;2(3):252-7 e1; quiz 8. http://www.ncbi.nlm.nih.gov/pubmed/24811013Picard M, Giavina-Bianchi P, Mezzano V, Castells M. Expanding spectrum of mast cell activation disorders: monoclonal and idiopathic mast cell activation syndromes. Clin Ther. 2013 May;35(5):548-62. http://www.ncbi.nlm.nih.gov/pubmed/23642289Ustun C, DeRemer DL, Akin C. Tyrosine kinase inhibitors in the treatment of systemic mastocytosis. Leuk Res. 2011 Sep;35(9):1143-52. http://www.ncbi.nlm.nih.gov/pubmed/21641642