Uterine relaxants

Question 1: List the drugs that are classified as uterine relaxant or Tocolytic :

Tocolytic drugs suppress uterine contractions and are used to delay or postpone premature labour. The main classifications include:

Beta Agonists
• Ritodrine
• Salbutamol
• Terbutaline [1]

Magnesium Sulfate
• Can be used as a tocolytic agent [2]

Calcium Channel Blockers
• Nifedipine - inhibits intracellular calcium entry and selectively inhibits uterine contraction [2]

Other Agents
• Prostaglandin synthesis inhibitors (Ibuprofen, Indomethacin)
• Ethyl alcohol [1]

Question 2 : Explain the action of the Tocolytic drugs :

These drugs act as tocolytic agents by reducing intracellular calcium concentration, which suppresses uterine contractions [3].

Tocolytic drugs suppress uterine contractions by reducing intracellular calcium concentration

Drug Classes and Their Actions

• Beta agonists (Ritodrine, Salbutamol, Terbutaline): Act as tocolytic agents by reducing calcium levels

• Magnesium sulfate: Can be used as a tocolytic agent

• Calcium channel blockers (Nifedipine): Inhibit intracellular calcium entry and selectively inhibit uterine contraction with oral administration allowing rapid absorption and long duration (up to 6 hours)

• Prostaglandin synthesis inhibitors (Ibuprofen, Indomethacin): Can delay labour before it has started

Clinical Purpose

• Used to delay or postpone premature labour