Does St John’s Wort affect antibiotics? (benefits vs risks)

This article will discuss the various ways by which Saint John’s Wort can affect antibiotics. It will weigh the risks and benefits of using it with antibiotics and will mention other medicinal plants that can be taken with antibiotics.

Does St John’s Wort affect antibiotics?

Yes, Saint John’s Wort can affect antibiotics in various ways. To illustrate, it can enhance the activity of certain antibiotics against resistant bacteria, but it may also interfere with the metabolism and elimination of other antibiotics and decrease their potency.

Taking St. John’s Wort with antibiotics can be beneficial in some cases but may also be problematic. Moreover, people react to medications differently, and the occurrence and severity of interactions between SJW and antibiotics will vary from one person to another.

Thus, if you’re considering taking SJW with antibiotics, you should discuss this with your doctor first. They will assess the possible benefits and risks and determine the appropriate approach.

What are the benefits of taking SJW with antibiotics?

Hyperforin, one of the active constituents in St. John’s Wort, was found to inhibit the growth of gram-positive bacteria, especially staphylococcus aureus. This bacteria is present on the skin and gets involved in wound infections. SJW showed effectiveness in completely healing wounds that contain S. Aureus [1]. 

Moreover, St. John’s Wort can improve the antimicrobial activities of penicillin and methicillin against Penicillin-resistant Staphylococcus Aureus (PRSA) and Methicillin-resistant Staphylococcus Aureus (MRSA), respectively [1].

To illustrate, one mechanism by which MRSA and PRSA resist antibiotics is through the development of efflux pumps. Efflux pumps are proteins that move antibiotics out of the bacterial cell, preventing them from killing it. 

Hyperforin acts as an efflux pump inhibitor; it allows penicillin or methicillin antibiotics to enter bacterial cells and execute their anti-bacterial action without being expelled from the cells through these efflux pumps. Thus, taking SJW with these antibiotics leads to the restoration of their activity against S. Aureus [1].

Research also found that SJW interferes with quorum sensing in E. Coli, disrupting its ability to develop biofilms. This is another way by which SJW can reduce a bacteria’s resistance to antibiotics [2]. 

Can St. John’s Wort interact with antibiotics?

Saint John’s Wort causes multiple drug interactions because of its actions as a CYP3A4 inducer. Medications that get metabolized by CYP3A4 enzymes will experience faster metabolism and elimination if taken with St. John’s Wort. Therefore, they will be less potent and less effective [3].

Macrolide antibiotics, including erythromycin and clarithromycin, are metabolized via CYP3A4 enzymes. They may not be effective in treating infections when taken with SJW [3]. 

Furthermore, rifampicin is an antibiotic that induces CYP3A4 enzymes as well. The concurrent administration of rifampicin and SJW will result in significantly increased activity of CYP3A4 enzymes, which may be very dangerous in people taking other medications that are CYP3A4 substrates [3].

What are the side effects of taking SJW with antibiotics?

Before considering taking St. John’s Wort with an antibiotic, you must be aware of its possible side effects. SJW is commonly associated with insomnia, rash, and diarrhea. You may also experience vision and hearing impairments, as well as problems in the liver, kidneys, and reproductive organs [4].

Furthermore, it is important to understand that Saint John’s Wort may reduce the effectiveness of your other medications. It reduces the potency of warfarin, digoxin, theophylline, protease inhibitors, ivabradine, immunosuppressants, and certain anticancer medications [4].

Moreover, St. John’s Wort increases serotonin, and taking it with a serotonergic antidepressant increases the risk of serotonin syndrome, which is a very dangerous condition that can be life-threatening sometimes. It is advisable not to take it with SSRIs like Celexa and sertraline [4].

What herbs can be used with antibiotics other than SJW?

Alternative herbs or medicinal plants that can be beneficial when combined with antibiotics are mentioned below:

Medicinal plant or herb Beneficial effect
Uva Ursi [5]

It reduces the minimum inhibitory concentrations (MIC) of beta-lactam antibiotics like oxacillin and cemetazole and enhances their activity against MRSA. It is effective for lower urinary tract infections.

Cranberry [5] It inhibits the adhesion of microbes to their target infection sites, leading to synergistic effects with antibiotic drugs. It is effective in urinary tract infections caused by E. Coli.
Goldthread, oregano, and barberry They have berberine, which is a chemical that also prevents bacterial adhesion [5].
Skullcap It decreases the MICs of benzylpenicillin against MRSA and PRSA and enhances the anti-microbial activities of methicillin, ampicillin, amoxicillin, and cefotaxime.
Garlic It reduces the MIC of vancomycin and is effective against gram-positive and gram-negative bacteria.
Tea Tea reduces the MIC of beta-lactams.

Understanding the possible effects of St. John’s Wort on antibiotics

Based on my research, I found that Saint John’s Wort can impact the effectiveness and safety of antibiotics in multiple ways. For instance, it can enhance the effectiveness of penicillin and methicillin antibiotics against resistant bacteria by acting as an efflux pump inhibitor.

However, based on my knowledge, Saint John’s Wort can also negatively impact the efficacy of other antibiotics by increasing the rate of their metabolism by CYP3A4 enzymes and decreasing their potency. Examples of these antibiotics include macrolides like erythromycin and clarithromycin.

Moreover, I believe that St. John’s Wort can cause various side effects and drug interactions. Thus, I recommend consulting with a doctor before taking it with an antibiotic. They will weigh the risks and benefits and determine whether it’s safe and beneficial to add SJW to your treatment plan.

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