🔴 Mechanism of Action 🔴

🔺 Uterine relaxants (Tocolytics)

🔸1. Adrenergic agonist :- MOA already discussed.....
e.g. Ritodrine, Isoxsuprine, salbutamol, terbutaline.

🔸2.Calcium Channel blockers :-

They simply block the calcium channel.... Cause reduction in tone of contractions.
e.g. Nigedipine and other dihydropyridines.

🔸3.Oxytocin Antagonist :-

e.g. Atosiban..... Antagonistic action on Oxytocin receptors.

🔸4. Miscellaneous Drugs :-

a. Magnesium sulphate :- Infused i.v. and it is first line drug for prevention and treatment of seizures in preeclampsia and eclampsia.

b. Other drugs like Ethyl alcohol, nitrates, progesterone, general anaesthetics and indomethacin (Prostaglandin synthesis inhibitors) which can depress uterine contractions. However, their effect is not dependable and they are NOT used clinically as a tocolytics.