There are a variety of antihistamines that can be purchased in over-the-counter form and there are also several that are only available in a prescription form. This type of medication is commonly used by many allergy sufferers because of their effective ability that they have in being able to blocking the problem causing histamine from being allowed to cause the frustrating symptoms that so many people experience during the allergy season, as well as those who experience these problems all throughout the entire year. There are some people that should not take this type of medication however, and would include women who have recently had a baby and are breastfeeding, people who have been diagnosed with narrow-angle glaucoma, and those that use a (MAOI), which is a monoamine oxidase inhibitor. This type of medication comes in a variety of forms that include liquid, capsules, tablets that are chewable, tablets that are to be swallowed, and there are also nasal spray antihistamines. Before taking this medicine, it is advised to speak with your family health care provider. They have the experience to equip you with information on any side effects and drug interactions that can occur while taking this drug.