Misoprostol (Cytotec©)

Section 1.1

Midwives may independently prescribe, order and administer this drug.

Cytotec©, is a synthetic prostaglandin E1 analog and induces uterine contractions. Misoprostol is a water soluble tablet.

Indications and Clinical Use:

1) Treatment of postpartum uterine atony or postpartum hemorrhage only when injectable uterotonics are not available. Where IM oxytocin can be repeated and there is no IV treatment with oxytocin or IM ergot alkaloids available, repeating IM oxytocin is preferred to misoprostol. Misoprostol is not as effective as oxytocin or ergot in management or prevention of postpartum hemorrhage and carries a significant risk of pyrexia and GI symptoms. Misoprostol may be used when IV oxytocin is not available after a prophylactic IM oxytocin has been administered during the third stage of labor, although it is not preferred.

2) Treatment of retained placenta in the absence of bleeding: Misoprostol or oxytocin can be injected into the umbilical vein. Refer to instructions provided for Injection of the Intra-Umbilical Vein for Retained Placenta.

3) Cervical ripening for induction of labour: See Misoprostol for Induction of Labour: Drugs which a midwife may administer after consulting with and on the order of a medical practitioner. As with any induction method where a physician has prescribed the inducing pharmacological agent, the midwife may continue to be involved in the care as the condition warrants. A midwife with specialized practice certification may on her own responsibility initiate induction of labour in hospital with a cervical ripening agent and/or initiate and manage an IV oxytocin induction/augmentation of labour.

Contraindications:

Misoprostol should not be used in those with a history of allergy to prostaglandins.

Warnings and Precautions:

Misoprostol should be used with caution in those with pre-existing cardiovascular disease.

Pregnancy:

Contraindicated (oral)

Human Data Suggest Low Risk (Term Cervical Ripening)

Lactation:

Category L2 – Limited Data – Probably Compatible

Adverse Reactions:

Most common (especially with oral administration): GI – diarrhea (14-40%), abdominal pain (13-20%), pyrexia and shivering (11%). Pyrexia is more common when the dose exceeds 600 mcg. Greater incidence than 1%: nausea (3.2%), flatulence (2.9%), headache (2.4%), dyspepsia (2 %), vomiting (1.3%) and constipation (1.1%).

Dosage and Administration:

1) Treatment of PPH
*Used only when no injectable uterotonic such as oxytocin or ergometrine is available.
Oral: Usual dose: 400 mcg sublingual SL
400 mcg-800 mcg sublingual SL can be administered
Rectal administration (600 mcg-800 mcg) may be used if unable to take medications orally and injectable uterotonics are not available.

* Ergonovine, 0.2 mg IM, and misoprostol, 400 mcg to 800 mcg given by the oral, sublingual, vaginal or rectal route, may be offered as alternatives in vaginal deliveries when oxytocin is not available.
Misoprostol is supplied as 100 and 200 mcg tablets.

Onset of Action:

Oral – 8 minutes
Sublingual – 11 minutes
Peak serum concentration – 18-34 minutes
Vaginal – 20 minutes
Rectal – 100 minutes

Duration of Action:

Oral – 2 hours
Sublingual – 3 hours
Vaginal – 4 hours
Rectal – 4 hours

Half-life:

20 to 40 minutes.

2) Injection of the Intra-Umbilical Vein for Retained Placenta
Misoprostol injected into the umbilical vein can be considered for retained placenta in the absence of maternal bleeding.

The technique for injection of the intraumbilical vein is described below.

  1. Explain the procedure and obtain consent.
  2. Prepare a syringe with the medication in 30 cc normal saline. Crush and dissolve 4x 200 mcg tablets misoprostol or oxytocin 20-50 IU in 30 mL normal saline. Identify the umbilical vein. Recut the cord if necessary.
  3. Insert a size 10 nasogastric tube into the umbilical vein. If resistance is felt, retract the catheter by 1-2 cm and then advance further, if possible. If the catheter cannot be advanced further without force, inject the solution in this position.
  4. The tube has reached the placenta when the majority of the catheter is inserted and resistance is felt. Retract by 3-4 cm to ensure that the tip is in the umbilical vein and not in a placental branch.
  5. Attach the syringe to the catheter and inject the solution followed by clamping of the cord with the catheter.
  6. Note the time of the injection.
  7. Wait 10-30 minutes for the placenta to deliver.

3) Cervical ripening for induction of labour: See Cervical Ripening and Induction Agents in section 2.1: Drugs which a midwife may administer after consulting with and on the order of a medical practitioner.