Uterine Stimulants Pharmacology and Nursing Responsibilities

Vocabulary practice flashcards covering uterine stimulant classifications, mechanisms of action, clinical indications, contraindications, routes of administration, and essential nursing considerations.

Uterine Stimulants (Oxytocics / Uterotonics)

Medications that increase uterine contractions, primarily indicated to induce or augment labor and to prevent or treat postpartum hemorrhage (PPH) caused by uterine atony.

Uterine Tachysystole

Excessive uterine contraction activity that can compromise uteroplacental blood flow and precipitate fetal distress.

Uterine Atony

A condition characterized by a soft, boggy, poorly contracted uterus following delivery, which represents the primary cause of postpartum hemorrhage.

Oxytocin (Pitocin)

A uterine stimulant administered via IV infusion or IM injection that stimulates uterine smooth muscle to contract during labor and compresses intramyometrial blood vessels postpartum to curb bleeding.

Water Intoxication / Hyponatremia

A serious adverse effect associated with prolonged or excessive intravenous administration of oxytocin due to its intrinsic antidiuretic hormone-like activity.

Methylergonovine / Ergometrine (Methergine)

An ergot alkaloid uterine stimulant that directly acts on myometrial smooth muscle to produce rapid, strong, and sustained uterine contractions to manage postpartum hemorrhage.

Hypertension Contraindication of Methergine

The clinical contraindication precluding the use of methylergonovine in patients with pre-existing hypertension or preeclampsia/eclampsia due to its potent vasoconstrictive properties that cause acute blood pressure spikes.

Misoprostol (Cytotec)

A synthetic prostaglandin $E_1$ analogue administered via oral, sublingual, buccal, or rectal routes that binds prostaglandin receptors in uterine tissue to induce myometrial contractions and cervical softening/ripening.

Misoprostol Onset of Action

The route-dependent onset time of misoprostol, occurring in approximately $3\text{ to }11\text{ minutes}$ when administered sublingually and $20\text{ to }30\text{ minutes}$ when given orally or rectally.

Carbetocin (Pabal / Duratocin)

A synthetic oxytocin analogue administered as a single IV or IM dose that selectively binds oxytocin receptors, delivering prolonged, rhythmic uterine contractions to prevent uterine atony and postpartum hemorrhage without continuous IV infusion.

Post-Delivery Timing of Carbetocin

The critical administration mandate requiring carbetocin to be administered solely after the delivery of the infant as a single slow IV bolus over $1\text{ minute}$ (or IM injection), with repeat bolus doses strictly avoided.

Carboprost Tromethamine (Hemabate)

A prostaglandin $F_{2\alpha}$ ($\text{PGF}_{2\alpha}$) analogue supplied in a $250\,\mu\text{g/mL}$ solution administered exclusively via deep IM injection to treat refractory postpartum hemorrhage unresponsive to initial uterotonics.

Bronchospasm Risk of Carboprost

A major adverse reaction that makes active asthma or pulmonary disease an absolute contraindication to carboprost tromethamine due to drug-induced airway smooth muscle constriction.

Dinoprostone (Prostin E2)

A prostaglandin $E_2$ ($\text{PGE}_2$) agent formulation (such as a $3\text{-mg}$ vaginal tablet or gel) inserted high into the posterior fornix to facilitate cervical softening, effacement, dilation, and induction of labor contractions.

Cervical Effacement and Dilation

The progressive anatomical changes of the cervix during labor preparation, progressing from unripened ($0\%$ effacement) to fully thinned ($100\%$ effacement) and fully widened (complete dilation).

Cervidil Pessary Placement

The controlled positioning of a dinoprostone vaginal insert equipped with a withdrawal tape into the posterior fornix of the vagina to achieve gradual cervical ripening.

Dinoprostone Prior Uterine Surgery Contraindication

The prohibition of dinoprostone in clients with a history of previous cesarean delivery or extensive uterine surgery due to an elevated risk of catastrophic uterine rupture.

Dinoprostone to Oxytocin Transition Interval

The mandatory waiting period of at least $6\text{ hours}$ following administration of a Prostin $E_2$ vaginal tablet before initiating IV oxytocin infusion to avoid dangerous hyperstimulation.