Clarithromycin is a macrolide antibiotic used to treat bacterial infections of the skin, such as folliculitis and cellulitis, as well as respiratory tract infections like pneumonia, tonsillitis, and sinusitis. It can also be prescribed to treat gastritis caused by Helicobacter pylori.
The dose and length of treatment are determined by a healthcare provider. It is important to follow dosing instructions carefully to avoid side effects such as nausea, vomiting, abdominal pain, and changes in blood test results.
Clarithromycin is available by prescription in pharmacies as 250 mg and 500 mg tablets or as an oral suspension of 250 mg/5 mL. It is sold as the generic "clarithromycin" and under the brand name Biaxin, among others.
Indications for use
Clarithromycin is indicated for the treatment of:
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Skin infections, such as folliculitis, erysipelas, and cellulitis;
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Pneumonia;
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Exacerbations of chronic bronchitis.
Clarithromycin may also be prescribed to treat gastritis caused by H. pylori. In these cases, it is usually taken together with other medications, such as proton pump inhibitors (PPIs) and amoxicillin.
Dosing instructions
The way clarithromycin should be taken depends on its form.
Clarithromycin 250 mg and 500 mg tablets
The usual recommended doses are:
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Adults: One 250 mg tablet every 12 hours. For more severe infections, the dose may be increased to 500 mg (or two 250 mg tablets) every 12 hours.
Clarithromycin should always be taken as directed by a healthcare provider, typically for 7 to 14 days. It can be taken with food or milk to help reduce stomach discomfort or nausea.
Clarithromycin oral suspension 125 mg/5 mL and 250 mg/5 mL (for children)
The typical dose of clarithromycin oral suspension for children aged 6 months to 12 years is:
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7.5 mg per kg of body weight (equivalent to 0.3 mL/kg of the 125 mg/5 mL suspension) every 12 hours, not exceeding a maximum dose of 500 mg every 12 hours.
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Alternatively, 0.15 mL per kg of the 250 mg/5 mL suspension may be given twice daily, as prescribed by the pediatrician.
The suspension can be taken with food or milk. It is important to continue taking the medication for the full duration prescribed by a healthcare provider, even if symptoms improve before finishing the treatment, to prevent the infection from coming back.
Before using the suspension, the powder should be reconstituted with water to a total volume of 60 mL and shaken well. The correct dose should be measured using the dosing syringe provided in the package. Always shake the bottle well before each use to ensure the suspension is properly mixed.
Side effects
The most common side effects of clarithromycin include:
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Nausea and vomiting;
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Diarrhea;
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Abdominal pain;
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Altered taste;
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Difficulty sleeping;
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Headache;
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Changes in liver enzyme tests (AST and ALT);
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Skin rashes;
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Increased sweating.
In rare cases, clarithromycin may cause more serious side effects, such as seizures, irregular heartbeats (arrhythmias), agranulocytosis, or severe allergic reactions like angioedema or anaphylaxis.
Contraindications for use
Clarithromycin tablets (250 mg and 500 mg) are generally not recommended for children under 12 years old, and the 250 mg/5 mL oral suspension should not be used in children younger than 6 months.
This antibiotic is contraindicated for people with a known allergy to macrolide antibiotics (such as azithromycin or erythromycin), low potassium levels in the blood, heart rhythm disorders (such as ventricular tachycardia or atrial fibrillation), or severe kidney problems.
Clarithromycin should not be used together with certain medications, including ticagrelor, midazolam, statins (such as simvastatin and lovastatin), and ergot alkaloids (such as ergotamine and dihydroergotamine).
Make sure to always tell your healthcare provider about any medications or supplements you are taking.