CBD and Antibiotics (e.g. Amoxicillin, Ciprofloxacin, Azithromycin)
David ReichUpdated:Key points at a glance:
CBD may interact with antibiotics. Amoxicillin is generally considered to have a lower interaction potential. Pay attention to any gastrointestinal discomfort and start with a low CBD intake if used alongside prescribed medication. Ciprofloxacin requires particular caution, as it inhibits the enzyme CYP1A2 and can interact with other medicines, while CBD can affect other CYP enzymes involved in drug metabolism. Azithromycin is regarded as having a lower potential for interactions. Taking CBD and antibiotics two to three hours apart is sometimes discussed as a way to separate their use. Do not adjust the prescribed antibiotic dose on your own. Topical forms of CBD are usually considered to present a lower interaction risk. Always seek advice from a doctor or pharmacist before combining CBD with antibiotics.
CBD (cannabidiol) has attracted a lot of attention in recent years and is used by many people as a supplement in areas such as pain, tension and sleep. But what happens if you are taking prescription medicines such as antibiotics at the same time? This article looks specifically at “CBD and antibiotics” and the question of whether and how CBD can be combined with amoxicillin, ciprofloxacin and azithromycin. We provide an overview, practical pointers and a transparent assessment of the evidence and possible CBD drug interactions.
If you are generally interested in how CBD works in the body, you can read more here: Effects of CBD in the body. An overview of products can be found here: CBD oil.
The essentials: CBD and antibiotics (amoxicillin, ciprofloxacin, azithromycin)
CBD may influence how some medicines are processed in the body, mainly via liver enzymes (CYP450). For the commonly used antibiotics amoxicillin, ciprofloxacin and azithromycin, the interaction profile with CBD appears to differ.
- Amoxicillin + CBD: Interaction risk is considered relatively low. The main concern is additive gastrointestinal side effects. Start with a low CBD amount and discuss use with a doctor or pharmacist.
- Ciprofloxacin + CBD: Requires increased caution. Ciprofloxacin inhibits CYP1A2 and can interact with other medicines. CBD should only be used in combination after medical advice and with close monitoring.
- Azithromycin + CBD: Has a lower CYP interaction potential than some other macrolides. Combination with CBD is often tolerated but still warrants monitoring for symptoms.
- In general: Begin with a low CBD amount, separate CBD and antibiotic doses in time (about 2–3 hours), and avoid self-directed CBD dose increases during antibiotic treatment.
CBD and antibiotics: overview for amoxicillin, ciprofloxacin, azithromycin
| Active substance | Metabolism | Relevant mechanisms | Possible overlap with CBD | Practical takeaway |
|---|---|---|---|---|
| Amoxicillin | Mainly excreted unchanged via the kidneys | Not a relevant CYP substrate | Primarily potentially additive gastrointestinal side effects | Traffic light: Green – generally considered low risk; clarify with a doctor |
| Ciprofloxacin | Partly hepatic, mainly renal; CYP1A2 inhibitor | Interacts with CYP1A2 substrates (e.g. theophylline, tizanidine) | CBD mainly inhibits CYP3A4/2C19/2C9; theoretical multiple enzyme inhibition possible | Traffic light: Amber/Orange – increased caution, only after medical advice |
| Azithromycin | Predominantly biliary elimination | Lower CYP interaction potential than erythromycin/clarithromycin | Primarily potentially additive gastrointestinal/CNS effects; occasional liver parameter changes | Traffic light: Amber – often tolerated, monitor symptoms |
How CBD may influence drug processing (CYP450, transporters)
CBD can inhibit enzymes of the CYP450 system (especially CYP3A4, CYP2C19 and CYP2C9) and may therefore slow the breakdown of certain prescription medicines. This effect appears dose-dependent and varies between individuals. For amoxicillin, a CYP interaction is considered unlikely; for azithromycin, it is thought to be lower than for other macrolides; with ciprofloxacin, the main concern is the potential for additional interactions via its CYP1A2 inhibition with other medicines. Clinical data on the combination of CBD and antibiotics are limited, and most indications are mechanistic or theoretical.
More on CBD metabolism and interactions in general can be found here: CBD interactions.
CBD can inhibit certain liver enzymes (CYP450). This appears to be of little relevance for amoxicillin, relatively low for azithromycin, and requires extra caution with ciprofloxacin because of its additional interaction potential with other medicines.
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Amoxicillin + CBD
Metabolism and interaction risk
Amoxicillin is mainly excreted unchanged via the kidneys and is not considered a relevant substrate of the CYP450 system. Clinically significant pharmacokinetic CBD–amoxicillin interactions are therefore regarded as unlikely based on current knowledge.
What does this mean for CBD? (evidence)
To date, there are no clinical data clearly demonstrating a relevant interaction between CBD and amoxicillin. In theory, the main concern would be additive gastrointestinal effects (for example nausea or loose stools), as both CBD and amoxicillin can affect the gut.
Practical guidance for combining CBD and amoxicillin
- Introduce CBD in a low amount and keep the amount stable during the course of antibiotics.
- Separate CBD and amoxicillin doses by around 2–3 hours to make it easier to attribute any side effects.
- Monitor for gastrointestinal complaints; in the event of severe diarrhoea, pause CBD and seek medical advice.
- If you notice signs suggestive of an allergic reaction to amoxicillin (such as rash or breathing difficulties), seek urgent medical help.
- Discuss the planned use of CBD with a doctor or pharmacist if you have kidney problems or are taking several other medicines.
Ciprofloxacin + CBD
Particular features of fluoroquinolones (including CYP1A2)
Ciprofloxacin is a fluoroquinolone antibiotic and a known inhibitor of CYP1A2. It can significantly increase levels of CYP1A2 substrates (for example theophylline or tizanidine). It is partially metabolised in the liver, but mainly excreted renally. CBD is primarily an inhibitor of CYP3A4, CYP2C19 and CYP2C9; there are fewer consistent clinical data on CBD’s impact on CYP1A2.
Ciprofloxacin inhibits CYP1A2 and may therefore interact with additional medicines. CBD inhibits other CYP enzymes. Together, the theoretical interaction potential increases, particularly where several medicines are being taken at once.
What does this mean for CBD? (evidence)
There are hardly any clinical study data on CBD combined with ciprofloxacin. The potential risk is mainly relevant when additional CYP1A2 substrates are being taken at the same time. In the absence of such concomitant medicines, a direct interaction is considered less likely but cannot be ruled out. As with other combinations of CBD and prescription medicines, an individual medical assessment is advisable.
Practical guidance for combining CBD and ciprofloxacin
- Only combine CBD and ciprofloxacin after medical advice, especially if you are taking other medicines (for example theophylline, tizanidine or clozapine).
- Start with a low CBD amount and avoid self-directed increases while taking ciprofloxacin.
- Separate CBD and ciprofloxacin doses by about 2–3 hours and watch out for dizziness, palpitations, trembling or feelings of restlessness.
- If you notice tendon problems, pronounced dizziness or a racing heartbeat while on ciprofloxacin, stop taking it and seek medical advice promptly.
- Inform your doctor about any other substances that might affect liver enzymes or heart rhythm.
Azithromycin + CBD
Lower CYP potential compared with other macrolides
Azithromycin belongs to the macrolide group of antibiotics but appears to have a considerably lower CYP interaction potential than erythromycin or clarithromycin. It is predominantly eliminated via the bile and is not considered a strong CYP substrate.
What does this mean for CBD? (evidence)
Specific clinical data on CBD combined with azithromycin are sparse. In theory, additive side effects are possible (for example gastrointestinal complaints or tiredness). Occasional changes in liver parameters are described with azithromycin. If you have pre-existing liver problems, medical advice is advisable before using CBD alongside azithromycin.
Practical guidance for combining CBD and azithromycin
- Introduce CBD at a low amount and separate CBD and azithromycin doses in time (around 2–3 hours).
- Watch for symptoms such as persistent nausea, dark urine or yellowing of the eyes or skin, and seek medical assessment if these occur.
- Avoid combining azithromycin, CBD and other medicines or supplements that may affect heart rhythm (QT interval) without medical advice.
- Discuss CBD use with your doctor if you are taking several other prescription medicines or have a history of liver disease.
CBD during a course of antibiotics: practical do’s and don’ts
- Inform your doctor or pharmacist in advance about all medicines, including over-the-counter products, herbal remedies and supplements such as CBD.
- Start with a low CBD amount and avoid spontaneous increases while you are on antibiotics.
- Separate CBD and antibiotic doses by around 2–3 hours to help attribute any side effects.
- If you have liver disease, ensure close monitoring and discuss whether liver tests are appropriate.
- Do not combine CBD with antibiotics in cases of known severe liver disease without medical supervision.
- Avoid adding other sedating substances (for example certain sleep aids or alcohol) without checking with a healthcare professional.
- Do not self-manage serious infections with CBD or other supplements instead of medical care.
Side effects when combining CBD and antibiotics
CBD may be associated with tiredness, dry mouth or gastrointestinal complaints. Antibiotics frequently cause nausea or diarrhoea; allergic reactions can occur in some cases. With ciprofloxacin, tendon complaints, dizziness and neurological symptoms are described; with azithromycin, occasional changes in liver parameters; with amoxicillin, mainly gastrointestinal complaints or, less commonly, allergic reactions.
Gastrointestinal complaints and tiredness from CBD and antibiotics may add up. Rare warning signs (such as a pronounced rash, breathing difficulties or yellowing of the skin) should be assessed by a doctor without delay.
Forms of CBD use and interaction potential
- Topical CBD (creams, ointments): Has low systemic absorption, so the risk of CBD interaction with antibiotics is generally considered lower.
- Oral CBD (oils, capsules): Leads to systemic absorption and therefore a higher potential for interactions with prescription medicines that are processed by liver enzymes such as CYP3A4.
Who should take particular care with CBD and prescription medicines
- People with liver disease or a history of raised liver values.
- People taking several medicines, especially CYP1A2 substrates with ciprofloxacin (for example theophylline, tizanidine, clozapine).
- Pregnant and breastfeeding women: only use CBD after medical advice.
- Older adults and people with impaired kidney function (particularly when using ciprofloxacin or amoxicillin).
When to seek medical advice
- Severe or persistent dizziness, palpitations or feeling faint.
- Marked diarrhoea, bloody stools or ongoing vomiting.
- Yellowing of the eyes or skin, dark urine or severe upper abdominal pain.
- Rash, hives, breathing difficulties or swelling of the face or lips.
- Tendon or joint pain while taking ciprofloxacin.
If you are unsure about combining CBD with antibiotics, or if you develop new or worrying symptoms, seek medical advice promptly rather than adjusting doses on your own.
Consulting a doctor about CBD and antibiotics
Before combining CBD and antibiotics such as amoxicillin, ciprofloxacin or azithromycin, discuss the following with your doctor:
- Your current medicines (including herbal products and supplements such as CBD).
- Existing conditions, particularly involving the liver or kidneys.
- The planned CBD form (topical, oil, capsules) and approximate amount.
- Any new symptoms since starting antibiotics or CBD.
This allows your doctor to assess potential CBD drug interactions, consider the role of liver enzymes such as CYP3A4, and, if necessary, recommend monitoring.
Conclusion: CBD with amoxicillin, ciprofloxacin or azithromycin
Whether you can take CBD with antibiotics depends on the active substance, the CBD form and your individual situation. Amoxicillin + CBD is generally regarded as relatively low risk, azithromycin + CBD is often manageable with monitoring, while ciprofloxacin + CBD requires increased caution and medical supervision. Start with a low CBD amount, separate doses in time and stay alert for warning signs. Speak to a doctor or pharmacist beforehand – especially if you are taking other prescription medicines or have underlying health conditions.
Disclaimer: This article is for information purposes only and does not replace medical advice. Do not change medicines or dosages without consulting your doctor. No claims are made regarding the treatment or cure of illnesses.