Black cohosh linked to heart rate problems
22 October 2010
The herbal ingredient black cohosh (Cimicifuga racemosa) should be considered as a possible cause of unexplained heart rate problems, cardiologists believe.
Queensland cardiologists described a case where a woman was hospitalised because of fainting spells and investigations revealed she was having episodes of complete heart block (blocking of the heart's electrical signal, which causes the heart rate to slow down).
The woman had no history of other heart problems but had been taking a preparation containing black cohosh for 2 weeks to treat menopausal symptoms, the authors reported in the Medical Journal of Australia (2010; 193: 479-81).
Bradycardia (slow heart rate) is a widely listed side effect of black cohosh in non-academic literature, the authors said. While black cohosh was useful for treating menopausal symptoms, they warned it had not been subjected to the postmarketing surveillance that conventional medicines receive. (Postmarketing surveillance is the practice of monitoring a medicine or device after it has been released on the market.)
Last Reviewed: 22 October 2010
- McKenzie SC, Rahman A. Bradycardia in a patient taking black cohosh. Med J Aust 2010; 193: 479-81. http://www.mja.com.au/public/issues/193_08_181010/mck11518_fm.html (accessed 20 Oct 2010).
