Master Methergine Mechanism of Action with Picmonic

Methylergonovine and ergotamine function by stimulating smooth muscle contraction; therefore, the smooth muscle within the uterus is stimulated causing uterine contraction.

In addition to smooth muscle contraction, methylergonovine and ergotamine produce vasoconstriction. This effect is useful in the treatment of migraines, but may cause severe hypertension.

Methylergonovine and ergotamine constrict cerebral blood vessels to prevent and treat migraine headaches. This helps decrease migraines because when migraines occur, the cerebral blood vessels dilate.

Methylergonovine and ergotamine produce powerful contractions and are used in the treatment of postpartum hemorrhage. In postpartum hemorrhage, the uterus usually becomes boggy and is not able to contract properly to stop bleeding. These medications aid in producing contractions to firm the uterus and stop bleeding.

Methylergonovine and ergotamine stimulate the muscles within the stomach, resulting in increased gastrointestinal symptoms such as nausea, vomiting, and diarrhea. These side effects are very common.

Ergot alkaloids may cause severe hypertension due to the vasoconstrictor effects of these medications. This class of medication should be avoided for patients with preexisting hypertension. In addition, if blood increases too much, tissue perfusion may decrease resulting in ischemia. Be sure to assess for peripheral weakness, tingling of the toes and fingers, and angina.

Because these medications stimulate adrenergic receptors, the heart rate is likely to increase. Patients administered ergot alkaloids or methylergonovine should be assessed for increased heart rate and cardiac rhythm.

Methylergonovine and ergotamine are used as second line agents because their effects are often delayed. These medications are not recommended for inducing labor due to the delayed onset of contractions and should only be used for postpartum hemorrhage after the use of oxytocin. They are also indicated for only severe migraine headaches as they constrict dilated blood vessels.