Editing Side effect (section)

==Examples of therapeutic side effects==
{{See also|Serendipity}}
Most drugs and procedures have a multitude of reported adverse side effects; the information leaflets provided with virtually all drugs list possible side effects. Beneficial side effects are less common; some examples, in many cases of side-effects that ultimately gained regulatory approval as intended effects, are:
* [[Bevacizumab]] ([[Avastin]]), used to slow the growth of blood vessels, has been used against dry age-related [[macular degeneration]], as well as [[macular edema]] from diseases such as [[diabetic retinopathy]] and [[central retinal vein occlusion]].<ref>{{cite news |url=https://www.theguardian.com/medicine/story/0,,1799772,00.html |work=The Guardian |location=London |title=Drugs firm blocks cheap blindness cure | vauthors = Boseley S |date=17 June 2006 | access-date=2010-05-20}}</ref>
*[[Buprenorphine#Antidepressant features|Buprenorphine]] has been shown experimentally (1982–1995) to be effective against severe, refractory depression.<ref>{{cite web | vauthors = Gracer R |url=http://www.naabt.org/documents/The_Buprenorphine_effect_on_Depression.pdf |title=The Buprenorphine Effect on Depression |website=naabt.org |publisher=National Alliance of Advocates for Buprenorphine Treatment |date=February 2007 |access-date= 19 September 2015}}</ref><ref>{{cite journal | vauthors = Bodkin JA, Zornberg GL, Lukas SE, Cole JO | title = Buprenorphine treatment of refractory depression | journal = Journal of Clinical Psychopharmacology | volume = 15 | issue = 1 | pages = 49–57 | date = February 1995 | pmid = 7714228 | doi = 10.1097/00004714-199502000-00008 }}</ref>
* [[Bupropion]] (Wellbutrin), an [[anti-depressant]], also helps smoking cessation; this indication was later approved, and the name of the drug as sold for smoking cessation is Zyban. Bupropion branded as Zyban may be sold at a higher price than as Wellbutrin, so some physicians prescribe Wellbutrin for smoking cessation.{{Citation needed|date=December 2016}}
* [[Carbamazepine]] is an approved treatment for [[bipolar disorder]] and [[epileptic seizure]]s, but it has side effects useful in treating [[attention-deficit hyperactivity disorder]] (ADHD), [[schizophrenia]], [[phantom limb]] syndrome, [[paroxysmal extreme pain disorder]], [[neuromyotonia]], and [[post-traumatic stress disorder]].<ref>{{cite web | vauthors = Leehey K | url = http://www.leeheymd.com/charts/dep4_1.html | title = Mood Stabilizers for Bipolar Disorder (Manic Depressive) | archive-url = https://web.archive.org/web/20111113183807/http://www.leeheymd.com/charts/dep4_1.html | archive-date = 13 November 2011 | work = Leeheymd.com | date = 1 August 2003 | access-date = 17 August 2011 }}</ref>
* [[Dexamethasone]] and [[betamethasone]] in [[premature labor]], to enhance pulmonary maturation of the fetus.<ref name=wing>{{cite journal | vauthors = Wing DA, Powers B, Hickok D | title = U.S. Food and Drug Administration drug approval: slow advances in obstetric care in the United States | journal = Obstetrics and Gynecology | volume = 115 | issue = 4 | pages = 825–833 | date = April 2010 | pmid = 20308845 | doi = 10.1097/AOG.0b013e3181d53843 }}</ref>
* [[Doxepin]] has been used to treat [[angiodema|angioedema]] and severe allergic reactions due to its strong [[antihistamine]] properties.<ref>{{cite journal | vauthors = Shen WW, Mahadevan J, Hofstatter L, Sata LS | title = Doxepin as a potent H2 and H2 antihistamine for epigastric distress | journal = The American Journal of Psychiatry | volume = 140 | issue = 7 | pages = 957–8 | date = July 1983 | pmid = 6859336 | doi = 10.1176/ajp.140.7.957 | url = http://ajp.psychiatryonline.org/cgi/reprint/140/7/957 | url-status = live | archive-url = http://archive.wikiwix.com/cache/20110904040738/http://ajp.psychiatryonline.org/cgi/reprint/140/7/957 | archive-date = 2011-09-04 | url-access = subscription }}</ref>
* [[Gabapentin]], approved for treatment of [[seizures]] and [[postherpetic neuralgia]] in adults, has side effects which are useful in treating bipolar disorder, [[essential tremor]], [[hot flashes]], [[migraine]] prophylaxis, [[neuropathic pain]] syndromes, phantom limb syndrome, and [[restless leg syndrome]].<ref>{{cite web | url = http://idahodur.isu.edu/leaflets/2004/GABAPENTIN%20EDU%20LEAFLET%202004.pdf | title = Off-label Use of Gabapentin | archive-url = https://web.archive.org/web/20070809235342/http://idahodur.isu.edu/leaflets/2004/GABAPENTIN%20EDU%20LEAFLET%202004.pdf | archive-date = 9 August 2007 | work = Idaho Drug Utilization Review, educational leaflet| date = 2004 }}</ref>
* [[Hydroxyzine]], an antihistamine, is also used as an [[anxiolytic]].{{Citation needed|date=December 2016}}
* [[Magnesium sulfate]] in obstetrics for [[premature labor]] and [[preeclampsia]].<ref name=wing />
* [[Methotrexate]] (MTX), approved for the treatment of [[choriocarcinoma]], is frequently used for the medical treatment of an unruptured [[ectopic pregnancy]].<ref>{{cite web| archive-url= https://web.archive.org/web/20081011183525/http://drugs.nmihi.com/whd/pregnancy.html |url=http://drugs.nmihi.com/whd/pregnancy.html| archive-date= 11 October 2008 |title=Pregnancy |website=drugs.nmihi.com |publisher=(New Medical Information and Health Information)}}</ref>
* The [[SSRI]] medication [[sertraline]] is approved as an antidepressant but delays [[Ejaculation|sexual climax]] in men, and can be used to treat [[premature ejaculation]].<ref>{{cite web | vauthors = Deem SG |url=http://www.emedicine.com/med/topic643.htm |website=Emedicine.com |title=Premature Ejaculation | access-date= 2011-08-17 | url-status= live | archive-url= https://web.archive.org/web/20081201091923/http://www.emedicine.com/med/topic643.htm | archive-date= 2008-12-01}}</ref>
* [[Sildenafil]] was originally intended for [[pulmonary hypertension]]; subsequently, it was discovered that it also produces [[erection]]s, for which it was later approved.{{Citation needed|date=December 2016}}
* [[Terazosin]], an [[Alpha-1 blocker|α<sub>1</sub>-adrenergic antagonist]] approved to treat benign prostatic hyperplasia (enlarged prostate) and hypertension, is (one of several drugs) used off-label to treat drug induced [[Perspiration|diaphoresis]] and [[hyperhidrosis]] (excessive sweating).<ref>{{Cite journal |url=http://psychiatryonline.org/pb/assets/raw/sitewide/practice_guidelines/guidelines/mdd.pdf |title=Practice guideline for the treatment of patients with major depressive disorder|display-authors=3 | vauthors = Gelenberg AJ, Freeman MP, Markowitz JC, Rosenbaum JF, Thase ME, Trivedi MH, Silbersweig DA | journal = Am J Psychiatry | date =  2010 | volume = 167 | issue = Suppl 10 | pages = 9–118}}</ref><ref>{{cite journal | vauthors = Cheshire WP, Fealey RD | title = Drug-induced hyperhidrosis and hypohidrosis: incidence, prevention and management | journal = Drug Safety | volume = 31 | issue = 2 | pages = 109–26 | date = 2008 | pmid = 18217788 | doi = 10.2165/00002018-200831020-00002 | s2cid = 23041000 }}</ref>
* [[Thalidomide]], a drug sold [[over the counter]] from 1957 to 1961 as a [[tranquiliser]] and treatment for [[morning sickness]] of pregnancy, became notorious for causing tens of thousands of babies to be [[Teratology|born without limbs]] and with other conditions, or [[stillborn]]. The drug, though still [[List of thalidomide side effects|subject to other adverse side-effects]], is now used to treat [[cancer]]s and [[skin disorder]]s, and is on  the [[World Health Organization's List of Essential Medicines]].<ref name="WHO22nd">{{cite book| title = World Health Organization model list of essential medicines: 22nd list| year = 2021 | hdl = 10665/345533 | publisher = [[World Health Organization]]| location = Geneva | id = WHO/MHP/HPS/EML/2021.02 | hdl-access=free }}</ref>