Classification by Phasing
The rationale for creating multiphasic agents is based on the natural hormonal fluctuations in the female body:
- Monophasic — component dosages remain constant throughout the entire course (examples: Diane-35, Jeanine, Yaz/Yasmin, Logest, Femoden, Minisiston).
- Biphasic — the estrogen amount is stable, while the progestin level increases in the second half of the cycle (rarely used today; historical example: Anteovin).
- Triphasic — the progestin dose increases stepwise in two stages (examples: Tri-Regol, Tri-Mercaptophen/Tri-Merci).
Additional Therapeutic Effects
Beyond preventing unwanted pregnancy, these agents affect various body systems through the specific properties of individual progestins:
- Antiandrogenic effect: mediated by cyproterone acetate and dienogest. It helps reduce hirsutism, acne, oily seborrhea, and hair loss. Agents such as Diane-35 and Jeanine are effective in hyperandrogenism, and Jeanine is also used in the management of endometriosis.
- Antimineralocorticoid effect: drospirenone in Yasmin blocks fluid retention, preventing edema, breast tenderness, and weight gain.
- Cycle regulation and cancer protection: menstrual blood loss is reduced, lowering the risk of anemia and dysmenorrhea. The progestin component protects the endometrium and ovaries by neutralizing the mitogenic effects of estrogens.
Adverse Effects and Hemostasis
COC use may be accompanied by adverse reactions affecting various organ systems:
- Gastrointestinal and CNS: nausea, rare vomiting, migraine-like headaches.
- Reproductive system: breakthrough spotting, amenorrhea, breast tenderness.
- Cardiovascular system: edema and elevated blood pressure.
The primary risk factor is linked to the estrogen component (ethinyl estradiol), which stimulates the synthesis of coagulation factors and increases thrombotic risk. In healthy women, this risk is compensated by the simultaneous activation of the fibrinolytic system. However, in smoking patients, compensatory mechanisms are suppressed, making smoking an absolute contraindication.