A lot vs. Alot: 9 Grammatical Pitfalls
antihistamine an·ti·his·ta·mine (ān'tē-hĭs'tə-mēn', -mĭn)
Any of several drugs used to counteract the physiological effects of histamine.
Drugs that counteract the effects of a substance in the body called histamine. The body releases histamine, which causes many of the symptoms associated with allergies (sneezing, watery eyes, runny nose), in response to external agents such as pollen.