Answer

No, you should not take licorice with immunosuppressants without strict medical supervision. This combination carries a critical risk of increasing the plasma concentrations of certain immunosuppressants, which can lead to toxicity.

Evidence Assessment

Evidence Strength: Limited (Tier C) The assessment is based on pharmacological data regarding CYP450 enzyme inhibition rather than large-scale clinical trials. While the biochemical mechanism is well-established in pharmacology, the quality score is limited due to the lack of specific randomized controlled trials (RCTs) for this specific supplement-drug pair.

Clinical Evidence

The primary concern involves the interaction between licorice and immunosuppressants that are substrates of the cytochrome P450 3A4 (CYP3A4) enzyme, most notably cyclosporine. Licorice acts as a moderate inhibitor of CYP3A4. Because this enzyme is responsible for the metabolism and clearance of cyclosporine from the body, inhibition of the enzyme leads to decreased drug metabolism.

When metabolism is slowed, the plasma concentration of the immunosuppressant increases. This can result in supratherapeutic levels of the drug, significantly increasing the risk of dose-dependent toxicity and severe adverse effects.

Practical Guidance

• Populations at Risk: Patients undergoing organ transplantation or those with autoimmune disorders taking CYP3A4-metabolized immunosuppressants (e.g., cyclosporine, tacrolimus).
• Monitoring: If a patient is already taking these medications, any introduction of licorice requires immediate clinical monitoring of drug trough levels.
• Alternatives: Patients seeking the benefits of licorice (such as for gastrointestinal issues) should consider DGL (Deglycyrrhizinated Licorice), which has the glycyrrhizin removed and does not typically carry the same metabolic or hypertensive risks.

Safety & Interactions

Interaction Verdict: CRITICAL / CAUTION

• Drug Class: Immunosuppressants (specifically CYP3A4 substrates like cyclosporine).
• Mechanism: Moderate inhibition of the CYP3A4 enzyme, leading to increased plasma levels of the drug.
• Clinical Management:
  • Dose Adjustment: A reduction in the dose of the immunosuppressant may be necessary if licorice is consumed.
  • Monitoring: Frequent monitoring of blood drug levels and renal function is required to prevent toxicity.
  • Recommendation: It is strongly advised to avoid licorice in favor of safer alternatives or to use it only under the direct supervision of a healthcare provider.
• High-Risk Populations: Patients with chronic kidney disease (CKD) are at elevated risk, as cyclosporine toxicity can further exacerbate renal impairment.