The misoprostol is a semi – synthetic analogue of prostaglandin E 1 (PGE 1 ) used for the prevention and treatment of ulcers , gastric and duodenal ulcers , particularly secondary employment for long periods of time drugs nonsteroidal antiinflammatory drugs (NSAIDs) such as Ibuprofen , naproxen or aceclofenac. Its effect is directly on enterochromaffin or Kulchitsky cells (which release histamine), inhibiting its secretion. They also increase the secretion of mucus and bicarbonate in the stomach by an increase in mucosal irrigation. 1Misoprostol also reduces pepsin under basal conditions.

Myspess® misoprostol (Misodel, Mysodelle) in vaginal insert presentation with a controlled release mechanism is indicated for the induction of labor in women with or near pregnancy at term 2 3

The presence of the recovery system allows the doctor to accurately control the degree of cervical maturation with the possibility of interrupting the administration of the drug by removing the device at any time, when the clinical evolution of the patients so indicates.

It is also used, in some countries , for the practice of medical abortion and specifically for the induction of labor (always under medical supervision, due to the high risk of hemorrhage caused by misuse) and, in combination with other drugs such as Mifepristone , for voluntary termination of pregnancy . Therefore, misoprostol should not be used in pregnancy in order to treat an ulcer. 4 Associated with immunosuppressive drugs such as cyclosporine (Sandimmun), misoprostol is also used to reduce the percentage of rejections in transplanted patients, generally when the achieved levels of immunosuppressants do not achieve the desired effect.

In patients with kidney transplants, misoprostol compensates for renal vasoconstriction produced by immunosuppressants, increasing renal flow, and therefore, improving renal function in these patients.


Misoprostol is indicated for the prevention of ulcers caused by prolonged consumption of NSAIDs . Acts on the parietal cells of the stomach containing receptors to prostaglandins of the E series (stimulated by food, alcohol, NSAIDs, histamine, pentagastrin and caffeine) inhibiting acid secretion in the gastric juice via inhibition of adenylate cyclase mediated By binding to a G protein coupled receptor. The decrease in intracellular concentration of cAMP causes a decrease in proton pump activity at the apical surface of the parietal cell. 5

Misoprostol is somewhat less effective than the H2 antagonists of histamine (especially overnight), such as ranitidine , or the proton-pump inhibitor such as omeprazole (which act directly on the oxyntic cells of the gastric mucosa ), But more effective than sucralfate (Urbal) in the treatment of gastric and duodenal ulcers.

Labor Induction

The induction of labor is a set of procedures aimed at provoking uterine contractions in an artificial manner with the intention of triggering labor at the most appropriate time for the mother and the fetus. The evaluation of the characteristics of the cervix has been considered one of the predictive factors of the prognosis of the induction of labor 6

Induction of labor is used when there is an indication of termination of pregnancy and labor does not occur spontaneously. Induction of labor reduces the maternal and fetal risks of continuing the pregnancy. Risks include: increased fetal and neonatal mortality and meconium aspiration syndrome, as well as increased neonatal care. 7

The cervical tissue is composed of smooth muscle, connective tissue and collagen; Its activity is therefore influenced by prostaglandins. Prostaglandins begin the process for cervical preparation or ‘ripening’, being effective agents for cervical maturation and induction of labor in term pregnancies.

The vaginal insert of misoprostol, of Myspess commercial name, is a matrix of hydrogel that measures 30 x 10 x 0.8 mm with 200 micrograms of misoprostol. The recovery system is 30 cm long and ensures easy and safe disposal of the product, after the 24-hour dosing period or at the beginning of active labor. The presence of moisture permits the release of misoprostol in vivo at a rate of about 8 mcg per hour, up to 24 hours; Controlled release of a low and continuous dose of Misoprostol over a prolonged period, regulating tissue exposure to PGE1, which minimizes the probability of uterine hyperstimulation; While maintaining the benefit of having a short period of time until safe vaginal delivery. If factors such as the need for patient monitoring, time savings and patient comfort are taken into account, the use of the Misoprostol vaginal insert may be a good therapeutic option. 8 9

The introduction of the vaginal insert of Misoprostol as well as its withdrawal are simple procedures that do not involve the use of a syringe, vaginal speculum or stirrups. The insert must remain sealed in the aluminum foil pack and stored in a freezer (-10 to -20 ° C) until it is to be used, no thawing is required prior to use. The vaginal insert is placed between the index and middle fingers and placed crosswise in the posterior fornix, using small amounts of water-soluble lubricants to aid placement of the vaginal insert. The recovery system comprises a bag (containing the Misoprostol-hydrogel insert) and a strip for withdrawal. The bag and ribbon are made of polyester. At the end of the dosing period, or if it is necessary to stop the administration of the drug, the vaginal insert of Misoprostol can be easily removed by gentle traction on the recovery tape. Because of the short half-life of Misoprostol (30 to 40 minutes), the effects of the drug are expected to cease rapidly after withdrawal.

In a randomized clinical study involving 1,358 pregnant women, we studied the efficacy and safety of the 200 microgram vaginal insert misoprostol, compared to 10 milligrams of the dinoprostone vaginal insert. Proving that the use of misoprostol vaginal insert of 200 micrograms decreases the median time for vaginal delivery in 11.3 hrs compared to dinoprostotone vaginal insert. Efficacy was consistent in primiparous or preterm women. Prolonged labor is associated with higher rates of infection and increased use of antibiotics. Careful monitoring of both the mother and the fetus is required during the use of misoprostol since abnormal uterine contractions “Tachysystole” may be present, an event expected by the use of misoprostol. 10

Abortion with medication

Main article: Abortion with drugs

Misoprostol is used to stop pregnancy because it induces labor by promoting uterine contractions and preparing the cervix for labor. In these functions, misoprostol is considered more effective than oxytocin and dinoprostone , the drugs legally indicated for induction of labor. It is considerably cheaper than these medicines. In Colombia, Ecuador and Peru where abortion is not legal, it is the most used drug for that use, opening debates about its free marketing and orientation, it is noteworthy that in these 3 countries there is a great demand of counterfeit medicines of this type being commercialized Very insecure. [ Citation needed ] In Argentina various organizations submitted a request to the National Administration of Medicines, Food and Medical Technology recognizes the misoprostol as obstetrical medicine. Another request was submitted to the Ministry of Health of the Nation for the Ministry of Health to produce and distribute misoprostol (and mifepristone). eleven

Misoprostol, together with mifepristone, are the reference drugs for medical abortion . 12

The World Health Organization maintains information on use: Total 800 mcg of vaginal misoprostol repeated every 24 hours up to three doses. This regimen should only be used when neither mifepristone nor methotrexate is available because it is less effective. 13

When used for medical abortions, Misoprostol is also known as ” Miso “. 14

Several agencies and societies, including the World Health Organization, promote the use of misoprostol to induce labor. 15 The concern with the use of misoprostol, especially in high doses, is that it causes uterine rupture , especially in women with a previous cesarean section , fetal death or cerebral hemorrhage in the neonate . 16


  • Food decreases the absorption rate of misoprostol, so the time to reach maximum plasma concentration is prolonged.
  • In some clinical studies, misoprostol increased cyclosporine-induced nephrotoxicity (immunosuppressive drug used in patients with organ transplants).
  • If given along with oxytocin, it can cause uterine hypertonia, so it is advisable to administer oxytocin until after the last dose of misoprostol. 17
  • When antacids are given along with misoprostol, there is a decrease in the bioavailability of misoprostol.


  1. Back to top↑ Rang, HP (2016). «30». Rang and Dale Pharmacology . Spain: Elsevier. P. 372. ISBN  978-84-9022-958-3 .
  2. Back to top↑ BENITEZ-GUERRA, Gidder and DE CONNO ALAYA, Alfonso. Induction of labor with oral and vaginal misoprostol. RFM. [on-line]. jun. 2007, vol.30, no.1 [quoted June 08, 2009], p.61-67. Available on the World Wide Web: [1]. ISSN 0798-0469 .
  3. Return to top↑ Induction of labor in the Second Level of Care. Mexico: Ministry of Health; 21 / March / 2013 .
  4. Back to top↑ by MedlinePlus (January 2003). Misoprostol . Medical Encyclopedia in Spanish . Retrieved on July 25, 2008 .
  5. Back to top↑ Katzung, Bertram G. (2007). «Chapter 63. Drugs Used in the Treatment of Gastrointestinal Diseases». Basic & Clinical Pharmacology (9th edition). McGraw-Hill . P. 1471. ISBN  0071451536 .
  6. Back to top↑ «Misoprostol – Prospectus of Misive 200 Micrograms-vaginal tablets of Misoprostol, sinaem, Ministry of Health, Spain».
  7. Back to top↑ World Health Organization (January 2004). “Medical methods for abortion in the first trimester”. The Reproductive Health Library. Accessed September 3, 2004 .
  8. Back to top↑ Erica Hellenstein (June 27, 2014). «The Rise of the DIY Abortion in Texas». The Atlantic .
  9. Back to top↑ WHO. «WHO Essential drug list 2005 section 22.1 website» .
  10. Back to top↑ Erica Hellenstein (June 27, 2014). «The Rise of the DIY Abortion in Texas». The Atlantic .
  11. Back to top↑ Sonia Tessa (12/18/16). “The missing pill” . Page 12 . Consulted on 2/17/17 .
  12. Back to top↑ Misoprostol – Misive 200 Micrograms Prospectus – Misoprostol vaginal tablets, sinaem, Ministry of Health, Spain
  13. Back to top↑ World Health Organization (January 2004). “Medical methods for abortion in the first trimester” . The Reproductive Health Library . Accessed September 3, 2004 .
  14. Back to top↑ Erica Hellenstein (June 27, 2014). «The Rise of the DIY Abortion in Texas» . The Atlantic .
  15. Back to top↑ WHO. «WHO Essential drug list 2005 section 22.1 website» . Accessed December 6, 2006 .
  16. Back to top↑ Alfonsi, Sharyn (November 30, 2004). Labor Induction Drug Under Fire . CBS Evening News . Accessed August 22, 2006 .
  17. Back to top↑ «Vandecum. Misoprostol . ” Accessed October 15, 2016 .