Title: Biochemical effects in women following one year's exposure to a new triphasic contraceptive. II. Coagulation profiles.

POPLINE Document Number: 120199

Author(s):

Lox CD

Source citation:

GENERAL PHARMACOLOGY, 1996 Mar;27(2):371-4.

Abstract:

To assess the blood coagulation effects of an experimental triphasic contraceptive (35 mcg of ethinyl estradiol and 7 days each of 0.18, 0.215, and 0.25 mg of norgestimate), 39 non-smoking female volunteers were enrolled in a 12-month study. Coagulation variables were determined at baseline and after 3, 6, and 12 months of exposure. The increased risk of thromboembolism associated with some oral contraceptives has been linked to changes in the coagulation cascade. This new formulation produced no changes in overall hemostasis. Slight decreases were recorded in the intrinsic and common pathways of coagulation. There was a marked decrease in fibrinogen, especially in the 14 women with no prior exposure to hormonal contraception, and increases in several vitamin K dependent factors. Protein C antigen, a coagulation inhibitor, was elevated. The continual reduction over 12 months in fibrinogen activity recorded in this study should reduce the potential for fibrin deposition in the vascular system. Moreover, the slight activation of some clotting factors associated with low-dose norgestimate is effectively countered by the protein C increase.

Keywords:

Research Report
Clinical Trials
Oral Contraceptives, Phasic
Norgestimate
Blood Coagulation Effects
Thrombosis
Side Effects
Oral Contraceptives, Side Effects
Clinical Research
Research Methodology
Oral Contraceptives, Combined
Oral Contraceptives
Contraceptive Methods
Contraception
Family Planning
Contraceptive Agents, Progestin
Contraceptive Agents, Female
Contraceptive Agents
Hematological Effects
Hemic System
Physiology
Biology
Thromboembolism
Embolism
Vascular Diseases
Diseases
Treatment
Contraceptive Safety
Safety
Public Health
Health