Can You Take Amlodipine and Clarithromycin Together?

According to FDA drug labeling, amlodipine and clarithromycin are documented to interact. The interaction is rated as moderate in severity. The FDA label for clarithromycin specifically cautions against concurrent use of amlodipine with clarithromycin, though the specific mechanism of this interaction is not detailed in the FDA source record. This does not mean the combination is never safe, but it does mean that use together requires careful consideration and medical oversight.

What the Source Says

The interaction information comes directly from the FDA drug label for clarithromycin. The label groups amlodipine with other calcium channel blockers (verapamil, diltiazem, and nifedipine) and instructs prescribers to "use with caution" when these agents are combined with clarithromycin.

The FDA label notes that verapamil—another calcium channel blocker—has been associated with specific adverse effects when combined with clarithromycin, including hypotension (low blood pressure), bradyarrhythmias (abnormally slow heart rhythms), and lactic acidosis. For amlodipine and diltiazem, the label references the same precautions without repeating the full detail. For nifedipine, the label identifies it as a substrate for the enzyme CYP3A, which is relevant to understanding how drug interactions may occur in this class.

Source: FDA-approved drug label for clarithromycin (updated May 3, 2026, per the record supplied). The label is the authoritative FDA source document for prescriber guidance on this drug and its known interactions.

How to Understand This

To make sense of this interaction, it helps to understand what each drug does and how they may affect one another in the body.

Amlodipine is a calcium channel blocker used to treat high blood pressure and angina (chest pain). It works by relaxing blood vessel walls and slowing the heart rate, which lowers blood pressure and reduces the workload on the heart.

Clarithromycin is a macrolide antibiotic used to treat bacterial infections of the respiratory tract, skin, and other tissues.

The FDA source record does not specify the mechanism of interaction between amlodipine and clarithromycin. That is, the label does not explain why these two drugs interact or how one drug changes the behavior of the other in the body. The record only establishes that the interaction exists and that caution is warranted.

General pharmacology background may provide context: Many calcium channel blockers, including amlodipine, are metabolized (broken down) by hepatic enzymes, particularly CYP3A4. Clarithromycin is a known inhibitor of CYP3A4, meaning it can slow the breakdown of other drugs that rely on this enzyme. When amlodipine is metabolized more slowly, its concentration in the blood may increase, potentially heightening its effects—including lowering blood pressure further or slowing the heart rate more than intended. However, this general background is offered only as educational context. The FDA interaction record itself does not specify this as the established mechanism of the amlodipine–clarithromycin pair.

The "moderate" severity classification indicates that the interaction is clinically significant enough to require medical attention but is not in the highest-risk category. This suggests the combination may be manageable under appropriate medical supervision, rather than absolutely contraindicated.

Who Should Pay Particular Attention

The FDA labeling directs all prescribers to use caution when combining amlodipine and clarithromycin, without specifying a particular subgroup at heightened risk based on the source record provided. However, the documented concern with other calcium channel blockers in this same interaction—hypotension and bradycardia—suggests that patients already experiencing low blood pressure, slow heart rate, or heart conduction abnormalities, or those taking multiple blood-pressure-lowering agents, may warrant closer monitoring. This is general medical reasoning; the specific source record does not enumerate risk groups.

Patients with liver disease or who are taking other drugs that interact with CYP3A4 should particularly ensure their healthcare provider is aware of the combination, since the liver is central to drug metabolism.

Hypothetical Examples

Scenario 1 (Illustrative): A patient has been stable on amlodipine 5 mg daily for hypertension for several years. The patient then develops a respiratory infection and is prescribed clarithromycin 500 mg twice daily for 7 to 10 days. If amlodipine's metabolism is slowed during clarithromycin treatment, the amlodipine level in the bloodstream could rise, potentially causing a more pronounced drop in blood pressure or a slower-than-usual heart rate. A healthcare provider might monitor blood pressure and pulse more frequently during and shortly after the antibiotic course. This is a plausible concern based on general CYP3A4 inhibition, but the documented interaction record itself does not specify the mechanism or recommended monitoring interval.

Scenario 2 (Illustrative): A patient on amlodipine reports dizziness or lightheadedness within a few days of starting clarithromycin. This symptom could reflect a drug-drug interaction causing a drop in blood pressure, but it could also result from the infection itself, dehydration, or other causes. A pharmacist or physician would need to assess the temporal relationship, vital signs, and other clinical context to determine whether the amlodipine dose should be adjusted or clarithromycin should be replaced with an alternative antibiotic. The source record indicates caution is warranted; it does not provide a specific management algorithm.

What to Discuss With a Pharmacist or Physician

If you take amlodipine and are prescribed clarithromycin, or vice versa, your healthcare team should be aware of both medications. Consider discussing the following:

• Confirmation of the combination: Verify with your pharmacist that both drugs have been noted in your medication record. Sometimes pharmacists catch interactions at the point of dispensing; other times, patients must raise the question.
• Symptom monitoring: Ask whether you should watch for signs of excessive blood-pressure lowering (dizziness, lightheadedness, fainting, unusual weakness) or a slower-than-normal heart rate (unusual fatigue, shortness of breath, chest discomfort) while taking clarithromycin.
• Duration and context: Clarithromycin is typically prescribed for 7 to 14 days. Ask your prescriber whether the short duration of antibiotic therapy and the specific infection being treated justify proceeding with both drugs, or whether an alternative antibiotic might be safer.
• Frequency of follow-up: Discuss whether your blood pressure and heart rate should be checked during the antibiotic course or shortly after.
• Dose adjustment: Do not adjust your amlodipine dose on your own. If your healthcare provider suspects an interaction, they may recommend a temporary dose reduction or closer monitoring rather than a change in antibiotic. Any dose adjustment should come from your physician or pharmacist.
• Alternative antibiotics: If the combination is deemed unsafe in your particular situation, ask whether an alternative antibiotic that does not inhibit CYP3A4 (such as certain other macrolides, beta-lactams, or fluoroquinolones) might be appropriate. This decision is specific to your infection and medical history.
• Timing: Some interactions may be minimized by spacing doses, though the source record does not specify whether such strategies apply here. A pharmacist can advise on any timing considerations specific to your regimen.

Key Takeaways

• Amlodipine and clarithromycin have a documented moderate-severity interaction according to FDA drug labeling. The label directs prescribers to use caution when combining these drugs.
• The FDA source record does not specify the precise mechanism of this interaction, though general pharmacology suggests that clarithromycin's inhibition of the enzyme CYP3A4 may slow amlodipine metabolism and raise amlodipine levels in the blood.
• Potential adverse effects—particularly low blood pressure and slow heart rate—parallel those documented for clarithromycin combined with other calcium channel blockers such as verapamil.
• The combination is not necessarily forbidden, but it requires medical oversight. Your pharmacist or physician should be aware of both medications and should monitor you for symptoms of excessive cardiovascular effects, especially during the typically short course of clarithromycin treatment.
• Never adjust your amlodipine dose on your own. If an alternative antibiotic is safer for your situation, that decision should come from your prescriber in consultation with your pharmacist.

Sources

• DailyMed: FDA-Approved Drug Labels — The National Library of Medicine's database of current FDA-approved drug labeling, including clarithromycin.
• OpenFDA — The FDA's publicly searchable database of drug labels and adverse event reports.
• RxNorm — The NIH/NLM reference standard for drug naming and classification.
• PubMed — The National Library of Medicine's literature database; search "amlodipine clarithromycin" or "calcium channel blocker macrolide interaction" for peer-reviewed background on related drug interactions.

The information in this article is based on the FDA-approved drug label for clarithromycin and is intended as educational material to help you understand the documented interaction between amlodipine and clarithromycin. It is not a substitute for professional medical or pharmaceutical advice. Before making any changes to your medications, confirm your full medication list—including over-the-counter drugs and supplements—at checkdruginteractions.com, and discuss any concerns with your pharmacist or physician. They can evaluate your individual health situation, the reason for each medication, and whether the combination is appropriate for you.