Medical treatment

Medical options include:

• non-hormonal treatment such as:
  • consider no medication, review 6 monthly - if symptoms tolerable
    
    
  • analgesia e.g. NSAID'S, paracetamol
    • although commonly used to relive painful periods, a Cochrane review (2005) showed no significant decrease in pain in NSAID’s users or benefit of one type over the other (1)
    • NICE state that should
      • consider a short trial (for example, 3 months) of paracetamol or a non-steroidal anti-inflammatory drug (NSAID) alone or in combination for first-line management of endometriosis-related pain
      • if a trial of paracetamol or an NSAID (alone or in combination) does not provide adequate pain relief, consider other forms of pain management (e.g. neuromodulators and neuropathic pain treatments) and referral for further assessment
• hormonal treatments -
  • aim to induce atrophy within ectopic endometrium either by suppressing the activity of oestrogen on the ectopic endometrium, or by suppressing ovarian production of oestrogen, either directly or indirectly via the suppression of pituitary function
  • NICE state:
    • explain to women with suspected or confirmed endometriosis that hormonal treatment for endometriosis can reduce pain and has no permanent negative effect on subsequent fertility
    • offer hormonal treatment (for example, the combined oral contraceptive pill or a progestogen) to women with suspected, confirmed or recurrent endometriosis
    • if initial hormonal treatment for endometriosis is not effective, not tolerated or is contraindicated, refer the woman to a gynaecology service, specialist endometriosis service (endometriosis centre) or paediatric and adolescent gynaecology service for investigation and treatment options
      
      
  • options for treatment of endometriosis include:
    • combined oral contraceptive pill
      • used as initial treatment (often with NSAID’s) (1)
      • taken cyclically has the potential to reduce menstrual bleeding, and so to relieve symptoms of endometriosis
      • taken continuously (e.g. for 3 months at a time) to avoid menstrual bleeding is another strategy sometimes used to control symptoms of endometriosis (3,6)
        
        
    • progestogens
      • common oral progestogens taken in high daily doses to induce amenorrhoea include;
        • medroxyprogesterone acetate
          • for mild to moderate endometriosis a dose of 10 mg three times per day for 90 consecutive days is recommended
        • dydrogesterone
        • norethisterone (2)
      • levonorgestrel-releasing intrauterine system -
        • helpful in relieving endometriosis-related pain (7)
        • may also be an effective therapy for rectovaginal endometriosis
          
          
    • GnRH analogues -
      • induce a medical oophorectomy - but very expensive
      • the use of concurrent add-back hormone replacement reduces the loss of bone mineral without interfering with the treatment's efficacy (7)
        
        
    • danazol -
      • given for 6-9 months to produce a "pseudomenopause"; it is a testosterone derivative which:
        • suppresses LH surge
        • inhibits ovarian steroidogenesis
        • reduces plasma levels of sex hormone binding globulin
        • increases free testosterone - due to reduced SHBG
      • the androgenic side effects have limited the clinical usefulness of this drug
        
        
    • gestrinone -
      • a synthetic steroid derived from 19- norethisterone
      • has similar actions and side effects to danazol
      • it however has a longer half- life than danazol and only requires to be taken twice a week

If a recurrence of symptoms of endometriosis in patients who have already had a diagnosis (6):

• recommencing the combined oral contraceptive pill (if not contraindicated) perhaps on a three-monthly continuous regimen, or using a GnRH agonist is appropriate. If this initial treatment measure fails to control the symptoms then referral to a gynaecologist is indicated (surgical management may be required)

Notes:

• an evidence based review classified treatment options as (4):
• beneficial treatments for endometriosis - combined oral contraceptives or medroxyprogesterone
• treatments where there was a trade-off between benefits and harms - danazol, gestrinone, or gonadorelin analogues
• treatment with unknown effectiveness - dydrogesterone
• medical therapy does not seem to improve fertility in women (5,6).

Reference:

• (1) Agarwal S. Diagnosis and treatment of endometriosis. MIMS monthly 2011
• (2) Amer S. Endometriosis. Obstetrics, Gynaecology and Reproductive Medicine 2008;18(5):126-133
• (3) Drug and Therapeutics Bulletin (1999);37 (4): 25-8.
• (4) Clinical Evidence (March 2005). Endometriosis.
• (5) Hughes E et al (1999). Ovulation suppression versus placebo in the treatment of endometriosis (Cochrane Review). In: The Cochrane Library Issue 3. Oxford: Update Software, 1999.
• (6) Prescriber (2004); 15(16):18-22.
• (7) Kroon N, Reginald P. Medical management of chronic pelvic pain. Curr. Obs. & Gynae. 2005; 15 (5): 285-290.
• (8) RCOG (2006) The investigation and management of endometriosis. Royal College of Obstetricians and Gynaecologists
• (9) NICE (September 2017). Endometriosis: diagnosis and management