[Oral contraceptive agents and antithrombin III]

Area of Science:

• Biochemistry
• Pharmacology
• Hematology

Background:

• Antithrombin III is a crucial inhibitor of coagulation and fibrinolysis proteases, including thrombin and factor X.
• Reduced antithrombin III levels, congenital or acquired, elevate thrombosis risk.
• Oral contraceptives are widely used, necessitating understanding of their impact on coagulation factors.

Purpose of the Study:

• To investigate the effect of oral contraceptives Gravistat and Nonovolan on antithrombin III activity.
• To determine if these hormonal contraceptives influence a key regulator of the coagulation cascade.

Main Methods:

• Thirty-five women using Gravistat or Nonovolan for at least one month were studied.
• Antithrombin III activity was measured using a kinetic colorimetric method with Chromasin TN.
• Blood samples were analyzed during different phases of the menstrual cycle.

Main Results:

• Mean antithrombin III activity was 107.5%, consistent with normal reference values.
• No significant differences in antithrombin III activity were observed across the three menstrual cycle phases (p > 0.05).
• The study found no reduction in antithrombin III activity in women using these oral contraceptives.

Conclusions:

• Hormonal contraceptive preparations Gravistat and Nonovolan do not appear to decrease antithrombin III activity.
• These findings suggest that Gravistat and Nonovolan may not increase thrombosis risk through a reduction in antithrombin III levels.