Misoprostol
From Wikipedia, the free encyclopedia
| Image:Misoprostol.png | |
| Misoprostol
| |
| Systematic (IUPAC) name | |
| methyl7-[3-hydroxy-2- (4-hydroxy-4-methyl-oct-1-enyl)- 5-oxo-cyclopentyl]-heptanoate | |
| Identifiers | |
| CAS number | 59122-46-2 |
| ATC code | A02BB01 |
| PubChem | 5282381 |
| DrugBank | APRD00037 |
| Chemical data | |
| Formula | C22H38O5 |
| Mol. weight | 382.5 g/mol |
| Pharmacokinetic data | |
| Bioavailability | extensively absorbed |
| Metabolism | de-esterified to misoprostol acid, then to prostaglandin F analogs |
| Half life | 20-40 minutes |
| Excretion | Renal:80% Fecal:15% |
| Therapeutic considerations | |
| Pregnancy cat. |
X |
| Legal status |
℞ Prescription only |
| Routes | Oral, Vaginal, Sublingual |
Misoprostol is a drug that is Food and Drug Administration (FDA)-approved for the treatment and prevention of stomach ulcers. It is also used to induce labor and as an abortifacient. It is marketed by G.D. Searle & Company under the trade name Cytotec, but generic versions are available as well.
Chemically, misoprostol is a synthetic prostaglandin E1 (PGE1) analogue.
Contents |
[edit] Indicated use
Misoprostol stimulates increased secretion of the protective mucus that lines the gastrointestinal tract and increases mucosal blood flow, thereby increasing mucosal integrity. It is sometimes co-prescribed with non-steroidal anti-inflammatory drugs to prevent their common adverse effect of gastric ulceration (e.g. with Diclofenac in Arthrotec).
[edit] Side effects and contraindications
The most common adverse effects of misoprostol include nausea, vomiting, diarrhea, abdominal pain, chills, shivering, sweating, and fever that can last as long as 3 weeks. Because of its abortifacient properties, it should not be taken by pregnant women.
[edit] Off label uses
[edit] Obstetric and gynecological
[edit] Labor Induction
Although not approved by the FDA for use as anything other than an ulcer drug, misoprostol is commonly prescribed off-label to cause birth induction by uterine contractions and the ripening (opening) of the cervix.<ref>Gaskin, Ina May (July-Aug 2001). "Induced and Seduced: The Dangers of Cytotec". Mothering.</ref> Misoprostol is highly effective and much less expensive than pitocin and cervidil, the FDA-approved drugs for medically necessary labor induction. The crucial difference between misoprostol and pitocin is that pitocin has a half-life of about 10 minutes and is administered via intravenous drip, which can be stopped immediately in the event of adverse reaction. The elimination half-life of sequential doses of misoprostol is not known, administration cannot be reversed, and adverse reactions can occur hours after the drug is taken. <ref>Ina May Gaskin (July 11, 2000). Cytotec: Dangerous Experiment or Panacea. Salon.com. Retrieved on 2006-09-08.</ref> The number of adverse effects is significantly greater in women treated with misoprostol than with cervidil. The manufacturer of Cytotec has explicitly warned that it is not approved for use in labor induction. The "routine" use of Cytotec is controversial. Speeding delivery can be medically necessary when the mother is overdue or at risk because of high blood pressure or diabetes, but critics charge that doctors often rely on Cytotec for "convenience inductions," using the drug to induce labor during office hours rather than letting nature take its course. "Cytotec enables doctors to practice daylight obstetrics," says Dr. Marsden Wagner, a neonatologist who served for 15 years as a director of women's and children's health in industrialized countries for the World Health Organization. "It means that as a doctor, I can come in at 9 a.m., give you the pill, and by 6 p.m. I've delivered a baby and am home having dinner." <ref>Goodman, David (2001). Forced Labor. Mother Jones.</ref> In May, 2005, the FDA sent out an alert to women, warning them against the use of Cytotec.<ref>FDA Alert-Risks of Use in Labor and Delivery. Center for Drug Evaluation and Research. FDA (May, 2005). Retrieved on 2006-08-22.</ref> A clinical trial is currently underway to establish a controlled delivery method for misoprostol.<ref>Clinical Trial Description at clinicaltrials.gov. Information on Clinical Trials and Human Research Studies. NIH (August, 2006). Retrieved on 2006-08-29.</ref> High doses can cause fetal death and uterine rupture and severe fetal brain damage <ref>Labor Induction Drug Under Fire. CBS News. Retrieved on 2006-08-22.</ref>
Whilst the American College of Obstetricians and Gynecologists advocates its use in labor inductions, the majority does not: the U.S. Food and Drug Administration and Searle (manufacturer of Cytotec) as well as opinions of obstetric organizations in Britain, Canada and Scandinavia, International Federation of Gynecology and Obstetrics, the World Health Organization and evidence based medicine Cochrane Database review.<ref>Marsden Wagner (Fall 2003). "Cytotec Induction and Off-Label Use". Midwifery Today (Issue 67).</ref>
[edit] Abortion
Misoprostol is one of the drugs used for chemical abortions. In many countries it is used in conjunction with mifepristone (RU-486). After mifepristone is taken orally, misoprostol is taken 24-72 hours later causing the expulsion of the fetus and associated matter in approximately 92% of the cases. No large studies have established a protocol for the use of misoprostol alone,<ref>Annotated Bibiography on Misoprostol Alone for Early Abortion. Gynuity Health Projects. Retrieved on 2006-08-22.</ref> and the range of efficacy is 65%-93% depending on sample size, gestational age, and other test variables;<ref>Medication Abortion: Misoprostol Alone. Ibis. Retrieved on 2006-09-08.</ref> Misoprostol alone may be more effective in earlier gestation.<ref>Instructions for Use: Abortion Induction with Misoprostol in Pregnancies up to 9 Weeks LMP (PDF). Gynuity Health Projects (2003). Retrieved on 2006-08-24.</ref> The side effects associated with the misoprostol-only regimen are generally much more severe than those associated with the combined regimens. Misoprostol is used for self-induced abortions in Brazil, where black market prices exceed US $100. per dose. Illegal medically-unsupervised misoprostol abortions in Brazil are associated with a lower complication rate than other forms of illegal self-induced abortion, but are still associated with a higher complication rate than legal, medically supervised surgical and chemical abortions. Failed misoprostol abortions are associated with birth defects in some cases. <ref>Corta, SH et al (1993). "Misoprostol and illegal abortion in Rio de Janeiro, Brazil". Lancet 15 (341). PMID 8098402.</ref> <ref>Coelho, HL et al (1994). "Misoprostol: the experience of women in Fortaleza, Brazil". Contraception 49 (2). PMID 8143449.</ref><ref>Barbosa, RM (1993). "The Brazilian Experience with Cytotec". Stud Fam Plann 24 (4): 236-40. PMID 8212093.</ref> <ref>Rocha, J et al (1994). "Brazil investigates drug's possible link with birth defects". BMJ 309 (6957). PMID 7950553.</ref> <ref>Gonzalez, CH et al (1993). "Limb deficiency with or without Mobius sequence in seven Brazilian children associated with misoprostol use in the first trimester of pregnancy". Am J Med Genet 47 (1). PMID 8368254.</ref> Poor immigrant populations in New York have also been observed to use self-administered misoprostol to induce abortions, as this method is much cheaper than a surgical abortion (about $2 per dose).<ref>John Leland: "Abortion Might Outgrow Its Need for Roe v. Wade", The New York Times, October 2, 2005</ref>
Misoprostol is sometimes used to treat early fetal death in the absence of spontaneous miscarriage, but further research is needed to establish a a safe, effective protocol. <ref>Neilson JP et al (2006). "Medical treatment for early fetal death (less than 24 weeks)". Cochrane Database Syst Rev 19 (3). PMID 16855990.</ref> It can also be used to dilate the cervix in preparation for a surgical abortion. Misoprostol is also used to prevent and treat post-partum hemorrhage, but it has more side effects and is less effective than oxytocin for this purpose. <ref>J Villar MD et al (2002). Systematic Review of Randomized Controlled Trials of Misoprostol to Prevent Postpartum Hemorrhage. Obstetrics & Gynecology. Retrieved on 2006-09-21.</ref>
[edit] Erectile dysfunction
A 1998 study found misoprostol to be helpful as a supplement to a vacuum pump (VED) in the treatment of erectile dysfunction, but not effective by itself.<ref>Ekmekçioğlu, Demirci, Yilmaz & Tatli (1998). "Intraurethral misoprostol: a different agent in the treatment of erectile dysfunction". Sexual Dysfunction 1: 161. DOI:10.1046/j.1460-2679.1998.00030.x.</ref> The paper concluded "The intraurethral application of misoprostol significantly improves the quality of VED-induced erections. This agent seems to be a cheap intraurethral adjunct to VED with mild to moderate local side-effects".
[edit] References
<references/>
[edit] External links and further reading
- Misoprostol from Drugdigest
- Pro-Life Nation, The New York Times Magazine, April 9, 2006. Reports on the use of Misoprostol in El Salvador, where abortion is illegal in all circumstances.de:Misoprostol
