Editing Recreational drug use (section)

====Antihistamines====
{{Further|Antihistamine}}
Antihistamines (or "histamine antagonists") inhibit the release or action of [[histamine]]. "Antihistamine" can be used to describe any histamine antagonist, but the term is usually reserved for the [[H1 antagonist|classical antihistamines]] that act upon the [[histamine H1 receptor|H<sub>1</sub> histamine receptor]]. Antihistamines are used as treatment for [[allergies]]. Allergies 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.{{Citation needed|date=July 2020}} High dosages taken to induce recreational drug effects may lead to overdoses. Antihistamines are also consumed in combination with alcohol, particularly by youth who find it hard to obtain alcohol. The combination of the two drugs can cause intoxication with lower alcohol doses.

Hallucinations and possibly delirium resembling the effects of [[Datura stramonium]] can result if the drug is taken in much higher than therapeutic doses. Antihistamines are widely available over the counter at drug stores (without a prescription), in the form of allergy medication and some [[cough medicine]]s. They are sometimes used in combination with other substances such as alcohol.
The most common unsupervised use of antihistamines in terms of volume and percentage of the total is perhaps in parallel to the medicinal use of some antihistamines to extend and intensify the effects of opioids and depressants. The most commonly used are [[hydroxyzine]], mainly to extend a supply of other drugs, as in medical use, and the above-mentioned ethanolamine and alkylamine-class first-generation antihistamines, which are – once again as in the 1950s – the subject of medical research into their anti-depressant properties.

For all of the above reasons, the use of medicinal scopolamine for recreational uses is also observed.