Can I take Myfembree (relugolix, estradiol, and norethindrone acetate) with Yaz (drospirenone and ethinyl estradiol) oral contraceptive?

Myfembree (Relugolix/Estradiol/Norethindrone Acetate) Should Not Be Taken With Yaz (Drospirenone/Ethinyl Estradiol)

Taking Myfembree (relugolix, estradiol, and norethindrone acetate) with Yaz (drospirenone and ethinyl estradiol) is not recommended due to potential drug interactions and redundant hormonal effects.

Rationale for Avoiding Concurrent Use

• Myfembree contains relugolix (a GnRH receptor antagonist) plus estradiol and norethindrone acetate as add-back therapy to prevent bone loss and vasomotor symptoms 1, 2
• Yaz contains drospirenone (a progestin) and ethinyl estradiol (a synthetic estrogen), functioning as a combined oral contraceptive 3
• Taking both medications simultaneously would result in:
  • Redundant hormonal components (two different estrogens and two different progestins) 2, 3
  • Potentially antagonistic mechanisms of action (GnRH antagonism from relugolix vs. hormonal feedback from Yaz) 2

Understanding Myfembree's Mechanism

• Myfembree works by:
  • Relugolix component suppresses ovarian production of estrogen and progesterone by blocking GnRH receptors 2
  • Estradiol (1mg) and norethindrone acetate (0.5mg) are included as "add-back therapy" to prevent bone mineral density loss and vasomotor symptoms 1, 4
  • This combination effectively treats heavy menstrual bleeding associated with uterine fibroids 4

Understanding Yaz's Mechanism

• Yaz functions as:
  • A combined oral contraceptive that prevents ovulation through hormonal feedback 3
  • Contains drospirenone (a progestin with anti-mineralocorticoid effects) that may actually decrease blood pressure 3
  • Approved for treatment of acne in women who desire contraception 3

Potential Risks of Combination

• Unpredictable hormonal effects due to:
  • Competing mechanisms (GnRH antagonism vs. hormonal feedback) 2, 3
  • Excessive estrogen exposure from two different sources (estradiol and ethinyl estradiol) 1, 3
  • Excessive progestin exposure from two different sources (norethindrone acetate and drospirenone) 1, 3
• Increased risk of adverse effects:
  • Potential for increased thromboembolic events 3
  • Possible enhanced hypertensive effects 3

Appropriate Alternative Approaches

• For patients on Myfembree for uterine fibroids:

  • Myfembree alone provides adequate treatment for heavy menstrual bleeding 4
  • No additional hormonal contraception is needed as Myfembree itself may suppress ovulation 2
  • Non-hormonal contraception methods (barrier methods, copper IUD) can be used if needed 3

• For patients on Yaz for contraception or acne:

  • Discuss with healthcare provider about transitioning to Myfembree if uterine fibroids are the primary concern 4, 5
  • Consider non-hormonal treatments for acne if switching from Yaz to Myfembree 3

Monitoring Recommendations

• If transitioning between these medications:
  • Allow for a washout period between discontinuing one medication and starting the other 2
  • Monitor for changes in menstrual bleeding patterns 4
  • Monitor blood pressure, as both medications can affect it differently (Yaz may decrease BP while other hormonal combinations may increase it) 3

Key Takeaway

• Myfembree and Yaz should not be taken concurrently due to overlapping hormonal components and potentially conflicting mechanisms of action 1, 2, 3
• Consult with your healthcare provider about which medication is most appropriate for your specific medical needs 4, 5