effect of all serotonin reuptake inhibitors, manifesting as delayed ejaculation, inability to achieve orgasm and decreased libido. Gastrointestinal effects such as nausea and vomiting, which depend on the dose and usually resolve within the first two weeks of treatment. Central nervous system disturbances such as anxiety, insomnia and sedation. Suicide risk: a combined analysis of placebo-controlled trials of various antidepressants including SSRIs in children and adolescents showed a doubled risk of suicide in those taking antidepressants. In response, the United States Food and Drug Administration issued a warning in 2004 regarding the elevated risk of suicidal thoughts and behavior in children and adolescents. Immunosuppressants Immunosuppressants may cause immunodeficiency, resulting in an increased susceptibility to infection. Other side effects include bone marrow suppression, increased risk of cardiovascular disease and increased risk of cancer. Capsaicin Being the main chemical that causes heat in chili pepper, the main side effect of capsaicin is a burning sensation that usually persists for several days. A topical anaesthetic can be used to reduce the sensation. In addition, the topical anaesthetic can also provide anti-itch effect on its own. History Abirritants have an extensive history in treating itch. The history of abirritants dates back to the Byzantine period, when Alexander of Tralleis, a famous physician, recommended crushed rue and alum mixed in honey for topical application to the scalp for itching caused by scabby conditions of the head. During the 7th century, Paul of Aegina, a famous Greek physician, described a list of drugs for treatment of itch including plants such as the squill, metallic components, and goat droppings which were applied externally. These drugs are common in ancient pharmacopeia. The Lorscher Azneibuch written in the monastery of Lorsch in the 7th century described many preparations of abirritants for both systemic and topical use, such as an ointment prepared from stinging nettle seeds. Mercury-coated girdles were used in the 17th century as an expensive treatment to alleviate symptoms of itch caused by scabies, but mercury toxins in the blood often caused other troubling symptoms in patients. In the 20th century, many new abirritants for external use emerged, including salicylic acids, naphthol, tar, carbolic acid, thymol, and menthol, which were mostly available in the form of ointments. Alcohol and opium were also commonly prescribed. See also Itching Atopic dermatitis References External links Antipruritics