What medications can induce periods in a woman with amenorrhea?

Medications to Induce Periods in Women with Amenorrhea

Progestin therapy is the first-line medication for inducing menstrual bleeding in women with amenorrhea who have adequate estrogen levels. The specific medication choice depends on the underlying cause of amenorrhea and the patient's estrogen status.

Diagnostic Approach Before Treatment

Before prescribing medications, determine the type of amenorrhea:

• Rule out pregnancy (most common cause)
• Evaluate estrogen status through:
  • Endometrial thickness on ultrasound
  • Progesterone challenge test (administration of oral progestin for 5-10 days)

Medication Options Based on Estrogen Status

For Euestrogenic Amenorrhea (Adequate Estrogen Levels)

Women who have amenorrhea but adequate estrogen levels (indicated by positive response to progesterone challenge):

1. Oral Progestins (First-line):

   • Norethindrone acetate: 5-10 mg daily for 5-10 days per month 1
   • Medroxyprogesterone acetate: 5-10 mg daily for 5-10 days per month 2

2. Injectable Progestins:

   • Depot medroxyprogesterone acetate (DMPA): Note that while this can be used for contraception, it may cause amenorrhea itself 3

For Hypoestrogenic Amenorrhea (Low Estrogen Levels)

Women with low estrogen levels (indicated by negative response to progesterone challenge):

1. Combined Hormonal Contraceptives:
   • Oral contraceptive pills containing both estrogen and progestin 3
   • Can be started at any time if pregnancy is ruled out
   • Requires 7 days of backup contraception if started >5 days after menstrual bleeding 3

Treatment Based on Underlying Cause

Functional Hypothalamic Amenorrhea

• Address underlying causes: weight gain, stress reduction, decreased exercise intensity 3
• Cyclic progestin therapy for endometrial protection
• Combined hormonal contraceptives if contraception is also desired 3

Polycystic Ovary Syndrome (PCOS)

• Cyclic progestin administration or combined hormonal contraceptives 4
• Oral contraceptives particularly beneficial for patients with concurrent hirsutism or acne 4

Hyperprolactinemia

• Treat with dopamine agonists (bromocriptine, cabergoline)
• Cyclic progestin or combined hormonal therapy for cycle regulation 4

Important Considerations and Contraindications

• Cardiovascular Risk: Women with history of thrombosis, cardiovascular risk factors, or smokers over age 35 should avoid estrogen-containing methods 5
• Liver Disease: Women with advanced liver disease may have altered estrogen metabolism, requiring careful medication selection 3
• Bleeding Disorders: NSAIDs can be used for 5-7 days to manage heavy bleeding that may occur with hormonal treatments 5

Monitoring and Follow-up

• Assess response to treatment after first cycle
• If bleeding does not occur with progestin challenge, consider:
  • Outflow tract obstruction
  • Severe hypoestrogenism requiring estrogen supplementation
  • Endometrial damage (Asherman syndrome)

Treatment Failure

If amenorrhea persists despite appropriate treatment:

• Reevaluate diagnosis
• Consider referral to reproductive endocrinologist
• For women desiring pregnancy with functional hypothalamic amenorrhea, ovulation induction may be required 3

Remember that amenorrhea is a symptom, not a diagnosis. The goal of treatment is not only to induce bleeding but also to address the underlying cause and prevent long-term complications such as endometrial hyperplasia or osteoporosis.