Clarithromycin

Clarithromycin is a macrolide antibiotic medicine available in Bangladesh under many brand names. Below are its uses, dosage, side effects and precautions — and all brands with their current prices.

Clarithromycin is prescribed for infections caused by clarithromycin-sensitive bacteria, including:

• Respiratory infections: pharyngitis, tonsillitis, sinusitis, acute otitis media, bronchitis and community-acquired pneumonia
• Skin and soft-tissue infections such as folliculitis and cellulitis
• Helicobacter pylori eradication in peptic ulcer disease, combined with amoxicillin and an acid-reducing medicine
• Certain atypical mycobacterial infections, under specialist care

Your doctor will decide whether Clarithromycin is appropriate based on the site of infection, your medical history and local resistance patterns. Do not use it for viral sore throat, the common cold or uncomplicated diarrhoea, where antibiotics give no benefit.

Always take Clarithromycin exactly as your doctor prescribes. Typical adult doses of Clarithromycin are:

• Most respiratory, skin and soft-tissue infections: 250–500 mg every 12 hours for 7–14 days
• H. pylori eradication: 500 mg twice daily for 7–14 days as part of triple therapy
• Extended-release tablets: 500–1000 mg once daily, swallowed whole with food

Immediate-release Clarithromycin may be taken with or without food; taking it with meals can reduce stomach upset. For children, the dose is calculated by body weight (usually 7.5 mg/kg twice daily) and must always be set by a doctor. People with kidney disease may need a reduced dose.

Most people tolerate Clarithromycin well, but some experience:

• An unusual metallic or bitter taste in the mouth — very common and harmless; it disappears once the course ends
• Nausea, vomiting, abdominal pain, indigestion or diarrhoea
• Headache, dizziness or difficulty sleeping
• Oral or vaginal thrush after prolonged use

Rare but serious effects include severe watery or bloody diarrhoea, irregular or racing heartbeat, fainting, yellowing of the eyes or skin, dark urine, severe skin rash, or unusual confusion. Stop the medicine and seek medical help immediately if any of these occur, and report all side effects to your doctor.

Clarithromycin is a prescription-only antibiotic. Bangladesh is facing a serious antibiotic-resistance crisis, driven largely by antibiotics bought without prescription and courses stopped halfway. Take Clarithromycin only when a doctor prescribes it, and complete the full course even if you feel better after two or three days — stopping early lets the strongest bacteria survive and return as resistant infections.

• Tell your doctor if you have heart rhythm problems, a slow heartbeat or low potassium, as Clarithromycin can prolong the QT interval
• Use cautiously in liver disease, kidney disease and myasthenia gravis
• Report severe or persistent diarrhoea during or after treatment without delay

Clarithromycin blocks a liver enzyme (CYP3A4) and interacts with many medicines. Tell your doctor about everything you take, especially:

• Statins: simvastatin and lovastatin must not be taken with Clarithromycin, and atorvastatin needs caution — there is a risk of severe muscle damage
• Domperidone and other QT-prolonging drugs — risk of dangerous heart rhythms
• Warfarin (bleeding risk), digoxin, theophylline, carbamazepine, colchicine and ergot medicines
• Verapamil, amlodipine and other blood-pressure medicines
• Some diabetes medicines, midazolam and certain psychiatric drugs

Do not start any new medicine, including herbal products, during the course without asking your doctor or pharmacist first.

Do not take Clarithromycin if you:

• Are allergic to clarithromycin, erythromycin, azithromycin or any other macrolide antibiotic
• Have a history of QT prolongation, ventricular arrhythmia (including torsades de pointes) or uncorrected low potassium or magnesium
• Are currently taking simvastatin, lovastatin, ergotamine, dihydroergotamine, ticagrelor, ranolazine or oral midazolam
• Have severe liver failure together with kidney impairment
• Take colchicine and also have kidney or liver disease

Always show your doctor your full medicine list and allergy history before starting Clarithromycin, and mention any previous reaction to an antibiotic, however mild it may have seemed.

Pregnancy: Clarithromycin is generally avoided in pregnancy, particularly in the first trimester, because animal studies have suggested possible harm to the foetus. It should be used only if the doctor judges that no safer alternative antibiotic is suitable. Always tell your doctor if you are pregnant or planning pregnancy before taking Clarithromycin.

Breastfeeding: Clarithromycin passes into breast milk in small amounts. Short courses are usually considered compatible with breastfeeding, but the baby may develop loose stools, oral thrush or feeding changes. Consult your doctor before use while nursing and report any unusual symptoms in the baby promptly.

Store Clarithromycin below 30°C in a cool, dry place away from direct sunlight and moisture — avoid bathroom cabinets and car dashboards, especially in Bangladesh's humid climate. Keep the medicine in its original blister or bottle, tightly closed, and always out of the reach and sight of children.

• Reconstituted Clarithromycin suspension should be kept at room temperature — do not refrigerate, as chilling can make it bitter and thick — and discarded after 14 days
• Never use the medicine after the expiry date printed on the pack
• Do not flush unused antibiotics; return them to a pharmacy where possible