**4. Conclusion**

Failure of prophylaxis with oxytocin in PPH (as demonstrated by the need for a rescue uterotonic) occurs commonly, necessitating the use of further oxytocin or other treatments to maintain haemodynamic stability. Uterotonics include ergometrine/methylergometrine & misoprostol, as shown in **Figure 3**. The major disadvantages of oxytocin are its short half-life (3–17 minutes) and its requirements for cold storage and transport. By modifying the oxytocin molecule, its half-life has been prolonged and its enzymatic degradation reduced. Carbetocin has more pronounced pharmacological effects. Its main advantage over oxytocin is a longer uterotonic activity, which obviates the need of a continuous infusion and has a standardised dosing of single injection recommendation, carbetocin can address the variations in dosing regimen as is with oxytocin.

The posology of carbetocin has tremendous benefit for the patient. Carbetocin selectively binds to oxytocin receptors present on the myometrium of the uterus, resulting in rhythmic contractions, increased frequency of existing contractions, and increased uterine tone. Another feature to note is that carbetocin selectively has a pronounced effect on the pregnant and immediate postpartum uterus.

#### **Points to Remember**

