From the Guidelines
It is not recommended to take black cohosh with tizanidine (Zanaflex) due to potential interactions and increased risk of adverse effects, particularly sedation and liver function alterations. Both substances can affect the central nervous system, and combining them may increase side effects like dizziness, drowsiness, and impaired coordination. Tizanidine is a muscle relaxant that works by decreasing nerve activity, while black cohosh is an herbal supplement sometimes used for menopausal symptoms that may have mild sedative properties, as noted in a study on menopausal symptoms after breast cancer 1. This combination could potentially lead to excessive sedation or enhanced muscle relaxation beyond what is intended with tizanidine alone.
Additionally, black cohosh may affect liver function, and tizanidine is metabolized by the liver, which could potentially alter how your body processes the medication, as tizanidine clearance is significantly reduced when given concomitantly with certain medications, such as ciprofloxacin and fluvoxamine 1. The use of black cohosh has also been associated with reports of liver failure, highlighting the need for caution when considering its use, especially in combination with other medications that may affect liver function 1.
Key considerations when evaluating the safety of combining black cohosh with tizanidine include:
- Potential for increased sedation and impaired coordination
- Effects on liver function and potential for altered medication metabolism
- Importance of medical supervision to evaluate individual health status and current medications
- Need for personalized advice from a healthcare provider before combining any herbal supplement with prescription medication.
From the Research
Black Cohosh and Tizanidine Interaction
There is limited research available on the specific interaction between black cohosh and tizanidine (Zanaflex). However, some studies provide information on the potential interactions between black cohosh and other medications:
- A case report published in 2024 2 highlights the potential risk of serotonin toxicity and rhabdomyolysis when black cohosh is taken with certain prescription medications, including those with serotonergic properties.
- Another study published in 2008 3 notes that black cohosh has been associated with serious safety concerns, but the evidence is largely based on case reports and observational studies.
- A review of clinical data published in 2002 4 states that no drug interactions are reported in the medical literature, but this may not be comprehensive or up-to-date.
Safety Considerations
When considering the use of black cohosh with tizanidine, it is essential to be aware of the potential risks:
- Black cohosh may have serotonergic properties, which could interact with other medications, including tizanidine, although the exact mechanism is not well understood 2.
- The safety of black cohosh is not fully established, and more research is needed to determine its potential interactions with other medications 5, 3.
- Patients should be cautious when taking black cohosh with any prescription medication, especially those with serotonergic properties, due to the potential risk of adverse interactions 2.
Recommendations
Given the limited available evidence, it is crucial to exercise caution when considering the use of black cohosh with tizanidine:
- Patients should consult their healthcare provider before taking black cohosh with any prescription medication, including tizanidine.
- Healthcare providers should be aware of the potential risks and monitor patients closely for any adverse effects when black cohosh is taken with other medications 2.