Black cohosh and St John's wort in the climacteric

• Black cohosh (cimicifuga racemosa) is a herbal medicine that has traditionally been used to treat a variety of conditions including rheumatism, rheumatoid arthritis, intercostal myalgia, sciatica, chorea, tinnitus, dysmenorrhoea, and uterine colic
  • currently black cohosh is mainly used to treat menopausal symptoms and it may become more widely used as women seek an alternative to hormone replacement therapy
    • there is evidence concerning the use of a fixed combination of black cohosh and St John's wort in reducing perimenopausal (climacteric) and depressive symptoms (1)
    • however the long term safety of black cohosh is not clear
• adverse effects of black cohosh include gastrointestinal irritation, headache, dizziness and vomiting
• hepatotoxicity with black cohosh - there have been 10 reports of suspected adverse reactions associated with black cohosh, 7 of which have been reports of hepatotoxicity
  • mechanism for hepatotoxicity with black cohosh is not known. However, an immunological response has been suggested

NICE state (3):

• there is some evidence that isoflavones or black cohosh may relieve vasomotor symptoms
  • however
    • multiple preparations are available and their safety is uncertain
    • different preparations may vary
    • interactions with other medicines have been reported
• there is some evidence that St John's wort may be of benefit in the relief of vasomotor symptoms, but there is uncertainty about:
  • appropriate doses
  • persistence of effect
  • variation in the nature and potency of preparations
  • potential serious interactions with other drugs (including tamoxifen, anticoagulants and anticonvulsants).

Reference:

1. Uebelhack R et al. Black cohosh and St John's wort for climacteric complaints: a randomized trial. Obstet Gynecol 2006;107:247-55.
2. Current Problems in Pharmacovigilance (2004); 30:1-12.
3. NICE (November 2015). Menopause: diagnosis and management