Hydroxyzine (HZ)

Hydroxyzine is a first-generation antihistamine of the diphenylmethane and piperazine class. Hydroxyzine has been used in medical practice with opioid analgesics to increase the analgesic efficacy of opioids, and by recreational drug users to maximise the effects of opiates, and/or preempt some side effects of opioids like itching, nausea, and vomiting. Hydroxyzine is classified as an antihistamine, antipsychotic, anxiolytic and is also used as a tranquilizer; especially common in dentistry and it retains some popularity in obstetrics, where for many years it was especially preferred for its ability to boost the effectiveness of opioids by using up the enzymes that break down the opioids and remove them from your body, as well as permit later use of scopolamine or benzodiazepines better than other drugs might. Hydroxyzine reduced escape failures in a learned helplessness paradigm in rats.