St. John's Wort (SJW) - Drug Interactions

Category: Education

Presentation Description

St.John’s wort (SJW) is a herbal supplement used to treat depression. SJW can interact adversely with drugs such as Warfarin, Cyclosporine, Oral contraceptives, Theophylline, Digoxin, HIV protease inhibitors, Selective Serotonin Re-uptake Inhibitors (SSRIs), CYP1A2 Substrates, CYP3A4 Substrates, CYP2C19 Substrates, CYP2C9 Substrates, etc.


Presentation Transcript

St.John’s Wort – Drug Interactions:

St.John’s Wort – Drug Interactions Dr. P.Naina Mohamed PhD Pharmacologist


Introdcution St. John’s wort (SJW) is an herb and is also known as Hypericum perforatum . St. John’s wort blooms around the birthday (June 24 th ) of John the Baptist and “ Wort ” is an old English word for plant. Hence, it is called as St. John’s wort . The extract of St. John’s wort (SJW) has been shown to inhibit the uptake of serotonin, noradrenaline and dopamine and hence it is useful as an antidepressant.

Introdcution (Contd):

Introdcution (Contd) Hypericin and Hyperforin found to be the active ingredients of St. John’s wort which can act on chemical messengers in the nervous system that regulate mood. St. John’s wort may also be used to treat heart palpitations, moodiness and other symptoms of menopause, attention deficit-hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), and seasonal affective disorder (SAD). Gastrointestinal symptoms, allergic reactions, dizziness/confusion, tiredness/sedation and dry mouth are the most commonly reported adverse reactions for SJW.

Significant SJW – Drug Interactions:

Significant SJW – Drug Interactions SJW can interact significantly with certain drugs including… Warfarin Cyclosporine Oral contraceptives Theophylline Digoxin HIV protease inhibitors Selective Serotonin Re-uptake Inhibitors (SSRIs ) CYP1A2 Substrates CYP3A4 Substrates CYP2C19 Substrates CYP2C9 Substrates

SJW – Warfarin Interactions :

SJW – Warfarin Interactions Close monitoring of INR should be undertaken in patients receiving SJW–Warfarin combination . http :// /

SJW – Cyclosporine Interactions:

SJW – Cyclosporine Interactions Patients taking St. John's wort concomitant with cyclosporine require close monitoring. /

SJW – Protease Inhibitors Interactions:

SJW – Protease Inhibitors Interactions

SJW – Oral Contraceptives Interactions:

SJW – Oral Contraceptives Interactions Use an additional form of birth control such as a condom, while taking birth control pills along with St. John's wort . http ://

SJW – Digoxin Interactions:

SJW – Digoxin Interactions

SJW – Theophylline Interactions:

SJW – Theophylline Interactions

SJW – SSRIs Interactions:

SJW – SSRIs Interactions Serotonin syndrome is characterized by at least three of the following: confusion, agitation, hyperreflexia , diaphoresis, shivering or tremor, nausea, diarrhoea , lack of co-ordination, fever, coma, flushing or rhabdomyolysis . The combination of SJW and SSRIs should be avoided.

SJW – CYP3A4 substrates Interactions:

SJW – CYP3A4 substrates Interactions Published in vitro studies suggest that hyperforin may induce the activity of CYP3A4.

SJW – CYP1A2 substrates Interactions:

SJW – CYP1A2 substrates Interactions Published in vitro studies suggest that hypericin may induce the activity of CYP1A2.

SJW – CYP2C19 substrates Interactions:

SJW – CYP2C19 substrates Interactions

SJW – CYP2C9 substrates Interactions:

SJW – CYP2C9 substrates Interactions


Conclusion Not all herbs and supplements are safe. There is evidence that taking SJW preparations can result in pharmacokinetic or pharmacodynamic interactions that present a risk to patients taking medicines. Due to significant interactions between St. John’s wort and some medications, France has banned the use of St. John’s wort products. Several other countries, including Japan, the United Kingdom, and Canada are in the process of including drug-herb interaction warnings on St. John’s wort products. The patients should consult their doctor or pharmacist to know about the safety of a supplement or herb. The patients should read trustworthy information about the supplements.


References Stockley’s Drug Interactions, 9e Karen Baxter Harrison's Online Featuring the complete contents of Harrison's Principles of Internal Medicine, 18e Dan L. Longo, Anthony S. Fauci , Dennis L. Kasper, Stephen L. Hauser, J. Larry Jameson, Joseph Loscalzo , Eds Hazzard's Geriatric Medicine and Gerontology, 6e Jeffrey B. Halter, Joseph G. Ouslander , Mary E. Tinetti , Stephanie Studenski , Kevin P. High, Sanjay Asthana Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7e Judith E. Tintinalli , J. Stephan Stapczynski , David M. Cline, O. John Ma, Rita K. Cydulka , and Garth D. Meckler The American College of Emergency Physicians Principles of Critical Care, 3e Jesse B. Hall, Gregory A. Schmidt, Lawrence D.H. Wood



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