ENZAPROST T

Indications

• Induction of labor
• Medical abortion
• Management of postpartum hemorrhage
• Termination of pregnancy

Dosage

Children: Refer to BNF for Children for appropriate dosing information based on the child's condition and age.

Adults: Refer to BNF for specific dosing guidelines, as doses may vary based on indication and clinical judgment.

Mechanism of action

Dinoprost exerts its effects by binding to specific prostaglandin receptors, leading to an increase in intracellular calcium levels, which subsequently stimulates uterine contractions. It can also alter cyclic AMP accumulation, demonstrating diverse responses that may vary by species. The drug promotes vasodilation in certain vascular beds while contracting smooth muscle in others. Dinoprost effectively reduces progesterone output, causing the regression of the corpus luteum, which interrupts early pregnancy.

Pharmacodynamics

Dinoprost has a significant impact on the uterine smooth muscle, inducing contractions that facilitate abortion or labor. It also plays a role in vasodilation and vascular smooth muscle contraction, depending on the site of action. The drug's effects are additive when used in combination with oxytocin, potentially enhancing uterine activity. The pharmacological actions of dinoprost are mediated through its interactions with eicosanoid pathways, influencing various physiological responses.

Pharmacokinetics

Dinoprost is rapidly absorbed and metabolized, with its pharmacokinetic profile characterized by a short half-life. The drug is primarily eliminated via metabolic pathways, including conversion to various inactive metabolites. Its distribution in the body is influenced by the lipid solubility of prostaglandins, with significant binding to tissues, particularly those involved in reproductive functions. The onset of action is usually quick, with effects observable shortly after administration.

Pregnancy

Dinoprost is contraindicated in pregnancy as it can induce uterine contractions and lead to abortion.

Breast-feeding

There is limited data on the excretion of dinoprost in human milk. Caution should be exercised when administering to breastfeeding women.

Storage

Store at room temperature, protected from light. Do not freeze.

Formulations

• Injectable solution

Mechanism of action

...THERE IS NO SINGLE PROSTAGLANDIN RECEPTOR. ... IT IS POSSIBLE TO DEMONSTRATE CALCIUM DEPENDENCE OF DIVERSE RESPONSES TO PROSTAGLANDINS & TO OBSERVE ALTERED CALCIUM FLUXES. ...PROSTAGLANDINS MAY EITHER STIMULATE OR INHIBIT ACCUM OF CYCLIC AMP. /PROSTAGLANDINS/ RESPONSES TO PROSTAGLANDIN F2ALPHA SHOW SPECIES VARIATION, BUT VASODILATATION HAS BEEN OBSERVED FOLLOWING INJECTION INTO HUMAN BRACHIAL ARTERY OF PGF2ALPHA... SUPERFICIAL VEINS OF HAND ARE CONTRACTED BY PFG2ALPHA... PROMPT SUBSIDENCE OF PROGESTERONE OUTPUT & REGRESSION OF CORPUS LUTEUM FOLLOWS PARENTERAL INJECTION OF PROSTAGLANDIN F2ALPHA... THIS EFFECT INTERRUPTS EARLY PREGNANCY, WHICH IS DEPENDENT ON LUTEAL RATHER THAN PLACENTAL PROGESTERONE. OXYTOCIN & PROSTAGLANDINS AFFECT UTERINE SMOOTH MUSCLES BY DIFFERENT MECHANISMS, & THEIR EFFECTS ARE ADDITIVE. POSSIBLE ADVANTAGES OF THEIR COMBINED USE ARE BEING EXPLORED. /PROSTAGLANDINS/