What is Clarithromycin?

Clarithromycin is a macrolide antibiotic used to treat certain bacterial infections. In acute sinusitis, it may be used when an antibiotic is considered appropriate, particularly when penicillin is not suitable, such as in people with penicillin allergy or intolerance.

This product page refers to clarithromycin supplied on a private prescription following an online consultation.

How does Clarithromycin work?

Clarithromycin works by interfering with bacterial protein production, which stops susceptible bacteria from growing and helps clear the infection. This may reduce symptoms such as facial pain or pressure, blocked nose and nasal discharge when the sinusitis is caused by bacteria.

What is Clarithromycin used for on this page?

On this product page, clarithromycin is used specifically for:

- Acute bacterial sinusitis where an antibiotic is considered appropriate

- Sinusitis symptoms such as facial pain or pressure, nasal blockage and thick nasal discharge when bacterial infection is suspected

- Situations where penicillin is not suitable, such as penicillin allergy or intolerance

It is not used here for:

- Routine treatment of simple viral colds

- Severe sinus infection with red-flag symptoms needing urgent assessment

- Long-term or recurrent sinus symptoms without further review

- Children unless specifically assessed for age-appropriate dosing

Your prescriber will confirm clarithromycin is appropriate based on your symptoms, medical history and any other medicines you are using.

Who may be suitable for Clarithromycin?

You may be suitable if:

- You have symptoms consistent with acute sinusitis and an antibiotic is considered appropriate

- Your symptoms have persisted, become more severe, or fit a pattern where bacterial infection is more likely

- Penicillin is not suitable for you

- You are able to take tablets and complete the full course

Your prescriber will consider:

- How long your symptoms have been present and how severe they are

- Whether you have fever, facial pain, worsening symptoms or other features suggesting bacterial infection

- Any history of penicillin allergy or intolerance

- Any other medicines or health conditions you have

before deciding if clarithromycin is suitable for you.

Who should not use Clarithromycin or needs medical advice first?

Do not use without medical advice if you:

- Are allergic to clarithromycin, erythromycin or other macrolide antibiotics

- Have severe sinus symptoms with swelling around the eyes, confusion, severe headache, visual disturbance or signs of serious illness

- Have severe vomiting or are unable to keep tablets down

- Have been told you have significant heart rhythm problems, including prolonged QT interval

- Are taking medicines that interact dangerously with clarithromycin

- Are pregnant without checking suitability first, as erythromycin is usually preferred in pregnancy where a macrolide is needed

Use with caution and seek prescriber advice if you:

- Have liver problems

- Have kidney problems

- Have myasthenia gravis

- Are taking statins, warfarin, colchicine, digoxin, carbamazepine or other medicines that may interact

- Have symptoms that are not clearly acute sinusitis or have had repeated episodes

How do I take Clarithromycin?

Your prescriber will confirm the exact directions.

Practical advice:

- Take it at evenly spaced times through the day

- Swallow with water

- It can be taken with or without food

- Finish the full course unless you are told otherwise by a healthcare professional

If your symptoms get worse, do not improve, or you become more unwell during treatment, seek medical advice.

General self-care advice

- Rest and keep well hydrated

- Simple pain relief such as paracetamol may help if suitable for you

- Saline nasal rinses or sprays may help with congestion

- Avoid smoking and smoky environments, as these may worsen symptoms

- Seek review if symptoms are severe, prolonged or repeatedly returning

Side effects and when to get help

Common side effects can include nausea, stomach upset, diarrhoea, altered taste and headache. These are often mild.

Seek medical advice urgently if you develop swelling of the face or throat, difficulty breathing, severe rash, persistent severe diarrhoea, jaundice, palpitations, fainting, or signs of a serious allergic reaction after taking the medicine.

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