Recreational drug use are caused by an excessive response of the body to allergens, such as the pollen released by grasses and trees. An allergic reaction causes release of histamine by the body. Other uses of antihistamines are to help with normal symptoms of insect stings even if there is no allergic reaction. Their recreational appeal exists mainly due to their anticholinergic properties, that induce anxiolysis and, in some cases such as diphenhydramine, chlorpheniramine, and orphenadrine, a characteristic euphoria at moderate doses. High dosages taken to induce recreational drug effects may lead to overdoses. Antihistamines are also consumed in combination with alcohol, particularly
National Pollen and Aerobiology Research Unit National Pollen and Aerobiology Research Unit The National Pollen and Aerobiology Research Unit or NPARU is a research institute in Worcester. It produces the UK's pollen count, and was the world's first pollen forecasting service. Aerobiology is the study of organic particles and organisms in the atmosphere. The National Pollen and Hayfever Bureau was founded in Norwich on 21 April 1983. Forecasts for Britain's six million sufferers of hay fever (allergic rhinitis) began from 1 June 1983; it was funded by Fisons Pharmaceuticals. Most hay fever sufferers are aged 15-24 in the months of June and July. Treatments are "Beconase"