vagina. after administration people should stay laying down for at least 30 minutes after they have received the drug. contraindications contraindications to a medication are any reasons to not use the drug. prostaglandin e2 (pge2) is used to induce labor and should not be used in people that are contraindicated to give birth vaginally or spontaneous labor. pge2 should not be used in people with allergies to prostaglandins or any components in the drugs formulations. pge2 should be stopped before other oxytocic agents like oxytocin are given. dinoprostone as a vaginal suppository is contraindicated for women with acute pelvic inflammatory disease or active disease of the cardiovascular, respiratory, hepatic, or renal systems. caution is required for people with a history of cervical malignancy, hypo- or hypertension, anemia, epilepsy, jaundice, asthma, or pulmonary diseases. the suppository formulation is also not indicated for viable fetus evacuation. endocervical gel is contraindicated in those with who have a history of c-sections or major uterine surgery, if the fetus is in distress and delivery is not imminent, vaginal bleeding throughout the pregnancy that is unexplained, history of difficult labors and deliveries, have cephalopelvic disproportion, less than six previous term babies with nonvertex presentation, hyper or hypotonic uterine patterns. toxicity when prostaglandin e2 (pge2) is given in excess, hyper-stimulation of the uterus occurs and immediate discontinuation of the drug usually results in resolution of toxic effects. if symptoms continue a beta adrenergic drug (e.g. terbutaline) can be used. there are many different dosage forms of pge2. the pharmacokinetic properties vary between dosage forms and should not be interchanged. a medication error was cited in the institute for safe medication practices where prostin e2 was used in place of cervidil. the hospital had run out of cervidil which is a 10 mg endocervical insert and the provider decided to use half of a 20 mg prostin e2 vaginal suppository. cervidil delivers the drug at a constant rate and can be removed as necessary while prostin e2 dissolves immediately and can not be removed. this error resulted in an emergency c-section since the fetus's heart rate dropped suddenly. pharmacokinetics the synthetic pge2 dinoprostone has a plasma half-life of approximately 2.5–5 minutes, after vaginal administration, with most metabolites being excreted in the urine. history swedish physiologist ulf von euler and british physiologist m.w. goldblatt, first discovered prostaglandins independently in 1935 as factors contained in human seminal fluid. prostaglandins were noted for having blood pressure reducing effects and smooth muscle regulation effects. prostaglandin e2 itself was identified in 1962 by swedish biochemist sune bergström in the seminal fluid of sheep. the structure of prostaglandins is conserved in mammals, but it is also produced by marine organisms which allowed for more research into their biological roles. prostaglandins were discovered to be products of arachidonic acid and with the ability to radio label arachidonic acid in the early 1960s, american chemist e.j. corey was able to synthesize prostaglandin e2 in the lab in the 1970. this advancement paved the way for later studies that helped define the actions and response of prostaglandin e2. prostaglandin e2 was approved for medical use in the united states in 1977 and it is on the world health organization's list of essential medicines. prostaglandin e2 was approved by the fda in 1977.