From the FDA Drug Label
If switching from a 21-day regimen of tablets, she should wait 7 days after her last tablet before she starts levonorgestrel and ethinyl estradiol tablets. She will probably experience withdrawal bleeding during that week. Although the occurrence of pregnancy is unlikely if levonorgestrel and ethinyl estradiol tablets are taken according to directions, if withdrawal bleeding does not occur, the possibility of pregnancy must be considered
The patient in question was switched from Marvelon 21 (a 21-day regimen) to Tri Cyclen. Withdrawal bleeding is possible for this patient, as she would have experienced a 7-day wait after her last Marvelon 21 tablet before starting Tri Cyclen, during which she will probably experience withdrawal bleeding 1.
From the Research
Yes, withdrawal bleeding is possible when switching from Marvelon to Tri-Cyclen, as the body adjusts to the new hormone formulation. This bleeding occurs when hormone levels drop during the pill-free or placebo week of oral contraceptives, triggering the shedding of the uterine lining. When changing between different birth control pills, the body may need time to adjust to the new hormone formulation, which can cause temporary irregular bleeding patterns.
Key Points to Consider
- Marvelon contains desogestrel (150 mcg) and ethinyl estradiol (30 mcg), while Tri-Cyclen contains norgestimate (in varying doses of 180,215, and 250 mcg through the cycle) and ethinyl estradiol (35 mcg) 2.
- The different progestin type and triphasic nature of Tri-Cyclen compared to Marvelon's monophasic formulation can lead to adjustment bleeding, as noted in studies on oral contraceptive regimens 3, 4.
- This irregular bleeding typically resolves within 2-3 months as the body adapts to the new hormone regimen.
- A study from 2005 4 found that continuous use of triphasic oral contraceptives, like Tri-Cyclen, is feasible with few adverse side effects, including breakthrough bleeding.
Recommendations
- Continue taking Tri-Cyclen as prescribed, even if experiencing breakthrough bleeding.
- If heavy bleeding persists beyond three months or causes significant discomfort, consult your healthcare provider for further evaluation, as this could indicate an underlying issue that needs attention 5.
- It's essential to monitor the bleeding and adjust the treatment plan as necessary to ensure the best outcome in terms of morbidity, mortality, and quality of life.