Cromolyn Sodium: A chromone complex that acts by inhibiting the release of chemical mediators from sensitized mast cells. It is used in the prophylactic treatment of both allergic and exercise-induced asthma, but does not affect an established asthmatic attack.Drug Incompatibility: The quality of not being miscible with another given substance without a chemical change. One drug is not of suitable composition to be combined or mixed with another agent or substance. The incompatibility usually results in an undesirable reaction, including chemical alteration or destruction. (Dorland, 27th ed; Stedman, 25th ed)Ketotifen: A cycloheptathiophene blocker of histamine H1 receptors and release of inflammatory mediators. It has been proposed for the treatment of asthma, rhinitis, skin allergies, and anaphylaxis.Mast Cells: Granulated cells that are found in almost all tissues, most abundantly in the skin and the gastrointestinal tract. Like the BASOPHILS, mast cells contain large amounts of HISTAMINE and HEPARIN. Unlike basophils, mast cells normally remain in the tissues and do not circulate in the blood. Mast cells, derived from the bone marrow stem cells, are regulated by the STEM CELL FACTOR.Vulvitis: Inflammation of the VULVA. It is characterized by PRURITUS and painful urination.Sodium: A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.Anti-Asthmatic Agents: Drugs that are used to treat asthma.p-Methoxy-N-methylphenethylamine: A potent mast cell degranulator. It is involved in histamine release.Anti-Allergic Agents: Agents that are used to treat allergic reactions. Most of these drugs act by preventing the release of inflammatory mediators or inhibiting the actions of released mediators on their target cells. (From AMA Drug Evaluations Annual, 1994, p475)