What are the contraindications for ashwagandha (Withania somnifera)?

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Ashwagandha (Withania somnifera) Contraindications

Ashwagandha is contraindicated in patients taking monoamine oxidase inhibitors (MAOIs), those with hyperthyroidism, personal or family history of thyroid disorders, pregnancy, autoimmune diseases, and in patients scheduled for surgery. 1

Major Contraindications

Medication Interactions

  • MAOIs: Complete avoidance is necessary as concomitant use can lead to severe hypertension and risk of cerebrovascular accidents 1
  • Sedative medications: Ashwagandha has sedative properties that can potentiate effects of benzodiazepines and other sedatives 1
  • Thyroid medications: May interfere with thyroid hormone levels and treatment 2
  • Immunosuppressants: Due to its immunomodulatory effects, may interfere with immunosuppressive therapy 3

Medical Conditions

  • Hyperthyroidism: Ashwagandha can increase thyroid hormone levels, potentially worsening hyperthyroidism 2
  • Thyroid disorders: Recent evidence shows ashwagandha can cause painless thyroiditis and thyrotoxicosis 2
  • Autoimmune conditions: Due to immunomodulatory effects, may exacerbate autoimmune diseases 3
  • Hormone-sensitive cancers: Theoretical risk due to effects on hormone levels 3
  • Liver disease: Caution advised due to potential hepatic metabolism 1
  • Diabetes: May affect blood glucose levels, requiring adjustment of antidiabetic medications 3

Special Populations

  • Pregnancy and breastfeeding: Traditionally used as an abortifacient; safety not established 3
  • Pre-surgery: Should be discontinued at least 2 weeks before scheduled surgery due to potential effects on blood pressure, blood glucose, and immune function 1
  • Children: Limited safety data in pediatric populations 3

Adverse Effects to Monitor

Common Adverse Effects (>5%)

  • Somnolence
  • Epigastric discomfort
  • Loose stools 3

Less Common Adverse Effects

  • Dizziness/giddiness
  • Drowsiness
  • Vertigo
  • Nasal congestion
  • Decreased appetite
  • Nausea
  • Dry mouth
  • Hyperactivity
  • Blurred vision 3

Clinical Considerations

Dosing Considerations

  • Lower doses should be used initially in elderly patients
  • Patients with known sensitivity to nightshade family plants should avoid ashwagandha
  • Dosing should be reduced in patients with compromised liver or kidney function 3

Monitoring Recommendations

  • Thyroid function tests should be monitored in patients with history of thyroid disorders
  • Blood glucose should be monitored in diabetic patients
  • Blood pressure should be monitored in hypertensive patients or those on antihypertensive medications 3, 2

Timing Considerations

  • Should be discontinued at least 2 weeks before surgery
  • May interact with CYP450 enzymes; spacing with other medications may be necessary 4

Common Pitfalls to Avoid

  1. Assuming herbal supplements like ashwagandha are universally safe because they are "natural"
  2. Failing to inquire about supplement use when taking patient medication histories
  3. Not recognizing potential drug-herb interactions, especially with sedatives and thyroid medications
  4. Overlooking the potential for ashwagandha to cause thyroid dysfunction, particularly in susceptible individuals 2
  5. Not considering the immunomodulatory effects in patients with autoimmune conditions or those on immunosuppressants

While some studies suggest ashwagandha is generally well-tolerated in healthy adults 5, the contraindications and potential adverse effects should be carefully considered, especially in patients with pre-existing medical conditions or those taking multiple medications.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Grapefruit-Drug Interactions

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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