Clarithromycin is used to treat certain bacterial infections of the ears, sinuses, throat, lungs or skin.
This medicine is also used together with other medicines to treat stomach ulcers caused by a type of bacteria known as Helicobacter pylori.
Clarithromycin may be used to treat other conditions as decided by your doctor.
Take Clarithromycin exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.
This medicine is available as a conventional or modified-release tablet or as an oral suspension.
You may take the conventional tablet and oral suspension with or without food.
If you are taking the modified-release type of tablet (usually labelled as “XL”, “MR”, or “ER”), take it together with food or immediately after a meal. Swallow it whole, do not divide, chew or crush the tablet.
Try to take it at the same time each day.
If you are taking an oral suspension, tap or invert the bottle to loosen the dry powder and add the specified volume of water to reconstitute the suspension. Shake the bottle well before you take it to ensure that the liquid is evenly mixed. Use the measuring spoon or cup provided to measure your dose.
The dose of this medicine will be decided by your doctor. Your doctor will advise you on the treatment timeframe depending on the type and severity of your infection.
Take Clarithromycin at regular intervals. Do not skip any doses. You must complete the entire course of this medicine. If you don't, the infection will not be properly controlled.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.
DO NOT double a dose under any circumstances.
If you often forget to take your medicine, let your doctor and pharmacist know.
Do not take this medicine if you ever had an allergic reaction (e.g. rashes, breathlessness, swollen eyes) to Clarithromycin or similar medicines such as azithromycin or erythromycin.
Alert your doctor if you have the following conditions:
- history of liver disease associated with prior use of this medicine
- low potassium level in the blood
- heart rhythm disorder e.g. history of irregular or abnormal heartbeat
- severe liver disease and at the same time with kidney disease
as Clarithromycin may not be suitable for you.
Do not take the modified-release type of tablet if you have severe kidney disease.
Do not take Clarithromycin with medicines used for mood disorder, migraine, cold or allergy, sleep disorder, stomach problems, gout, high cholesterol, chest pain or certain blood-thinning medicine. Please see the section “Can I take this with other medicines?” below for more information.
Inform your doctor if you have the following conditions:
- heart problems e.g. narrowing of the blood vessels of the heart
- slow heartbeat
- low magnesium level in the blood
- myasthenia gravis (muscle weakness disorder)
- liver disease
- moderate to severe kidney disease
Let your doctor know if you are pregnant or breastfeeding.
Be sure to check with your doctor or pharmacist before giving this medicine to a child.
For as long as you are taking Clarithromycin, you may need to have regular blood tests (e.g. kidney function, complete blood count) to check your body’s response to the medicine. Your doctor will advise you about how often you need to have blood tests.
Clarithromycin may cause any of the following side effects: headache, diarrhoea, nausea, unusual change in the sense of taste, vomiting, stomach pain, indigestion, difficulty sleeping, and excessive sweating.
Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
- rashes, breathlessness, swollen mouth or eyes
- yellowing of the skin or eyes, abdominal pain, dark coloured urine, tiredness
- severe diarrhoea or watery or bloody stools, stomach cramps, fever
- muscle weakness
- abnormal or fast heartbeat, passing out, chest pain
- rashes with peeling of the skin or blistering of the lips, mouth or eyes accompanied by fever
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Do not take Clarithromycin with the following medicines:
- medicines for migraine e.g. ergotamine, dihydroergotamine
- cholesterol-lowering medicines e.g. lovastatin, simvastatin, lomitapide
- medicines for cold or allergy e.g. astemizole, terfenadine
- medicines for stomach problems e.g. cisapride, domperidone
- pimozide (medicine for mood disorder)
- colchicine (medicine for gout or high uric acid level in the blood)
- midazolam (medicine for sleep disorder)
- ticagrelor (blood-thinning medicine)
- ranolazine (medicine for chest pain)
Inform your doctor and pharmacist if you are taking or using any of these medicines:
- medicines for irregular heartbeat e.g. digoxin, verapamil, quinidine, disopyramide
- blood-thinning medicines e.g. warfarin
- medicine for diabetes e.g. glimepiride, repaglinide, nateglinide, insulin
- medicines for epilepsy (fits or seizures) e.g. carbamazepine, phenytoin, phenobarbital, valproate
- medicines to treat fungal infections e.g. fluconazole, itraconazole
- medicines for TB (infection known as tuberculosis) e.g. rifampicin, rifabutin, rifapentine
- medicines for HIV infection e.g. ritonavir, atazanavir, efavirenz, nevirapine, etravirine, zidovudine, saquinavir
- medicines used in organ transplant or certain immune disorders e.g. ciclosporin, sirolimus, tacrolimus
- alprazolam (medicine for anxiety)
- medicines used to treat impotence e.g. sildenafil, tadalafil
- theophylline (asthma medicine)
- tolterodine (medicine used to treat overactive bladder)
- vinblastine (medicine for cancer)
- St. John’s wort (herbal medicine)
This list does not include all medicines that may interact with Clarithromycin.
Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
Store in a cool, dry place away from the reach of children.
Once you have mixed the powder with water, the oral suspension can be stored at room temperature of up to 30°C. Do not refrigerate it otherwise it may become less effective. Throw away any unused portion after 14 days.
Medicines must not be used past the expiry date.