progestogen-only injectable contraceptive
{{Infobox Birth control
|name = Long-acting reversible contraceptives (LARC)
|bc_type = Hormonal
|reversibility = Yes
|STD_protection_YesNo = No
|perfect_failure%=0.2|typical_failure%=6}}
Progestogen-only injectable contraceptives (POICs) are a form of hormonal contraception and progestogen-only contraception that are administered by injection and providing long-lasting birth control.{{cite book|author1=P. F. A. van Look|author2=Kristian Heggenhougen|author3=Stella R. Quah|title=Sexual and Reproductive Health: A Public Health Perspective|url=https://books.google.com/books?id=JBK3OukxOf0C&pg=PA82|date=January 2011|publisher=Academic Press|isbn=978-0-12-385009-6|pages=82–}}{{cite book|author1=Nagrath Arun|author2=Malhotra Narendra|author3=Seth Shikha|title=Progress in Obstetrics and Gynecology--3|url=https://books.google.com/books?id=AS3UBAAAQBAJ&pg=PA416|date=15 December 2012|publisher=Jaypee Brothers Medical Publishers Pvt. Ltd.|isbn=978-93-5090-575-3|pages=416–}} As opposed to combined injectable contraceptives, they contain only a progestogen without an estrogen, and include two progestin preparations:
- Medroxyprogesterone acetate (brand names Depo-Provera, Provera, Depo-subQ Provera 104){{cite book|author1=Mary Lee|author2=Archana Desai|title=Gibaldi's Drug Delivery Systems in Pharmaceutical Care|url=https://books.google.com/books?id=v0rLyVSc8EYC&pg=PA328|year=2007|publisher=ASHP|isbn=978-1-58528-136-7|pages=328–}} – 150 mg (intramuscularly) or 104 mg (subcutaneously) every 3 months
- Norethisterone enanthate (brand names NET EN, Noristerat, Norigest, Doryxas){{cite book|author=Chaudhuri|title=Practice Of Fertility Control: A Comprehensive Manual|url=https://books.google.com/books?id=pzanxKlcU74C&pg=PA154|date=1 January 2007|publisher=Elsevier India|isbn=978-81-312-1150-2|pages=154–|edition=7Th}} – 200 mg (intramuscularly) every 2 months
Mechanism of action
These POICs work by providing an influx of progesterone into the female body. This influx will signal to the body that it does not need to synthesize its own hormones to induce the cycle. Since the body does not release any hormones of its own, there are no fluctuations in levels to trigger the phases in menstruation and ovulation does not occur. {{Cite web |last=Hospital |first=The Royal Women's |title=Depo Provera |url=https://www.thewomens.org.au/health-information/contraception/depo-provera |access-date=2024-04-17 |website=The Royal Women's Hospital |language=en}}
Potential side effects
As will all birth control medications, certain side effects may occur from taking the hormonal supplements. Changes in menstrual bleeding may occur, such as a lighter flow or complete stop to the regular monthly menses, or abnormal bleeding throughout the cycle. Others have reported small weight gain, and increase in headaches or mood swings, and a decrease in libido.
Links to cancer
Some research has shown that women who have taken hormonal birth controls could possible be less likely to develop certain cancers, such as endometrial, cervical, and ovarian.{{Cite web |date=March 1, 2018 |title=Oral Contraceptives (Birth Control Pills) and Cancer Risk |url=https://www.cancer.gov/about-cancer/causes-prevention/risk/hormones/oral-contraceptives-fact-sheet |access-date=2024-04-17 |website=www.cancer.gov |language=en}} This is likely due to the fact that the hormonal birth controls stop the monthly cycle of injury and repair to the endometrial tissue. This consistent injury to the uterine tissues is thought to be a factor in developing certain cancers, so if it is stopped for a period of time, the tissue will be less damaged than that of someone who has never taken birth control.
On the contrary, it was shown that women who has previously or were currently taking a hormonal birth control had an increased risk in developing breast cancer. This risk decreased as the individuals stopped the birth control, but no data was found linked to the duration of time one was taking a contraceptive.
Research
Progestogens that have been studied for potential use as POICs but were never marketed as such include the progesterone derivatives algestone acetophenide (dihydroxyprogesterone acetophenide) (100 mg/month), chlormadinone acetate (250 mg/3 months), hydroxyprogesterone caproate (250–500 mg/month), gestonorone caproate (2.5–200 mg/1–2 months), and oxogestone phenpropionate (50–75 mg/month), and the testosterone derivatives lynestrenol phenylpropionate (25–75 mg/month), levonorgestrel butanoate, levonorgestrel cyclobutylcarboxylate, and levonorgestrel cyclopropylcarboxylate.{{cite book | author = Mokhtar K. Toppozada | chapter = Monthly Injectable Contraceptives | pages = 93–103 | editor1 = Alfredo Goldsmith | editor2 = Mokhtar Toppozada | title = Long-Acting Contraception | year = 1983 | oclc = 35018604 | url = https://scholar.google.com/scholar?cluster=14664537528797672080}}{{cite book|author=Dr. S. S. Kadam|title=PRINCIPLES OF MEDICINAL CHEMISTRY Vol. - II|url=https://books.google.com/books?id=Z7Pb3lJuRksC&pg=PA381|date=July 2007|publisher=Pragati Books Pvt. Ltd.|isbn=978-81-85790-03-9|pages=381–}} Some of these have been introduced for use in combined injectable contraceptives instead.Benagiano, G., & Merialdi, M. (2011). Carl Djerassi and the World Health Organisation special programme of research in human reproduction. Journal für Reproduktionsmedizin und Endokrinologie-Journal of Reproductive Medicine and Endocrinology, 8(1), 10-13. http://www.kup.at/kup/pdf/10163.pdf{{cite journal | vauthors = Toppozada M | title = The clinical use of monthly injectable contraceptive preparations | journal = Obstet Gynecol Surv | volume = 32 | issue = 6 | pages = 335–47 | date = June 1977 | pmid = 865726 | doi = 10.1097/00006254-197706000-00001 }}
See also
References
{{Reflist}}
{{Birth control methods}}
{{Hormonal contraceptives}}
{{Progestogens and antiprogestogens}}
{{Progesterone receptor modulators}}