Clarithromycin 250 mg

Category- Allopathy

Medicine Highlights

Clarithromycin Uses 

Clarithromycin is an oral medicine belonging to the category of antibiotics, and this medicine is used to treat bacterial infections such as: 

1. Respiratory tract infections such as pneumonia, bronchitis, and sinusitis 
2. Throat and tonsil infections (like pharyngitis) 
3. Skin and soft-tissue infections 
4. Ear infections (otitis media) 
5. Stomach ulcers  

Directions for use

1. If you forget to take this medicine, take it as soon as you remember. If it’s almost time for your next dose, skip the missed dose. 
2. Take this medicine exactly as prescribed by your doctor, at the same time each day.  
3. Do not stop taking this medicine without your doctor’s approval, even if you feel better.

Clarithromycin side effects 

More Common  

1. Nausea or vomiting 
2. Stomach pain or discomfort 
3. Diarrhea or loose motions 
4. Change in taste (metallic or bitter taste in the mouth) 
5. Indigestion or bloating 
6. Headache 

Less Common

1. Severe allergy: swelling of face or lips, rash, trouble breathing 
2. Severe diarrhea  
3. Liver trouble  
4. Heart rhythm problems  
5. Dizziness or fainting 
6. Hearing problems  

How Clarithromycin works 

Clarithromycin works by stopping bacteria from growing and multiplying. It does this by blocking the bacteria’s ability to make proteins, which are essential for their survival. Without these proteins, the bacteria become weak and eventually die, helping the body clear the infection and recover. 

Safety Measures and Warning 

Allergic Reactions or Hypersensitivity

If you have a serious allergy to clarithromycin, azithromycin, or erythromycin, taking it again can cause dangerous allergic reactions like swelling, breathing trouble, or severe rashes. Seek medical attention immediately in case of any serious allergic reaction. 

Heart Problems

This medicine may affect heart rhythm in some people. If you have irregular heartbeat or heart-related conditions, your doctor’s guidance is essential to prevent serious heart complications. 

Low Potassium or Magnesium Levels

These conditions can increase the risk of heart rhythm issues. Your doctor should assess and correct these levels before starting clarithromycin. 

Liver Problems

Clarithromycin is broken down by the liver. If you have liver disease or a history of liver injury, your doctor must be informed so they can decide whether this medicine is safe or choose an alternative.  

Pregnant or breastfeeding women

Clarithromycin should be used only if clearly needed. A doctor’s approval is necessary to ensure safety for both mother and baby. 

Clarithromycin Interaction with Other Medicines

Avoid taking Clarithromycin with the following medicines, as it may increase or decrease the desired effect, or in worse cases, it could be fatal: 

Clarithromycin Interaction with Food Product

Clarithromycin can be taken with or without food but taking it after meals may help reduce stomach upset, as advised by doctors. Alcohol should be avoided because it can irritate the stomach and strain the liver while you are on this medicine. Grapefruit or grapefruit juice should also be avoided, since it can increase side effects by raising the medicine level in the body.  

Storage

1. Store the medicine at room temperature 
2. Keep away from sunlight and moisture 
3. Keep out of reach of children 

Clarithromycin Chemical Structure

IUPAC (International Union of Pure and Applied Chemistry)/ Chemical name

(3R,4S,5S,6R,7R,9R,11R,12R,13S,14R)-6-[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy-14-ethyl-12,13-dihydroxy-4-[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-7-methoxy-3,5,7,9,11,13-hexamethyl-oxacyclotetradecane-2,10-dione  

Intake routine/cycle

Daily dose

Take Clarithromycin exactly as your doctor recommends. The dose may change based on your condition and how well you respond. Do not take more than prescribed without consulting your doctor. 

Missed Dose

If you forget to take your medicine, take the medication as soon as you remember. If it’s nearly time for your next dose, skip the missed one and continue with your regular schedule. Always consult the doctor before making any changes to your dosage. 

Overdose

It is not recommended to take more than 500 mg of clarithromycin twice a day, as it may cause severe overdose symptoms like nausea, vomiting, headache, tremors, restlessness, and rapid heartbeat. 

Clarithromycin Summary 

Clarithromycin is an oral antibiotic belonging to the macrolide class, used to treat bacterial infections in throat, ear, chest, lung, sinus, skin infections, and stomach infections caused by H. pylori. It works by blocking bacteria from making proteins, which stops them from growing and allows the body to fight off infection. It can be taken with or without food, though food may help reduce stomach upset. Common side effects include nausea, vomiting, stomach pain, diarrhea, headache, and metallic taste, while rare but serious effects can include allergic reactions, liver problems, heart rhythm issues, and hearing problems.  

Clarithromycin should not be taken by people who are allergic to it or similar antibiotics, have liver or heart problems, low potassium/magnesium, or are pregnant/breastfeeding unless approved by a doctor. Avoid alcohol and grapefruit while taking it, and always follow the doctor’s prescription and complete the full course for safe and effective treatment. 

FAQ’s

What are the uses of Clarithromycin tablet? 

Clarithromycin tablet is an antibiotic used to treat bacterial infections such as throat, chest, lung, sinus, ear, skin infections, and stomach infection (H. pylori) when prescribed by a doctor. 

What are the side effects of Clarithromycin?

Common side effects include nausea, vomiting, stomach pain, diarrhea, headache, and a metallic taste in the mouth. Rarely, it may cause allergic reactions, liver problems, heart rhythm issues, or hearing problems. If severe symptoms occur, consult a doctor immediately. 

What class of medicine does clarithromycin belong to?

Clarithromycin belongs to the macrolide antibiotic class and is used to treat bacterial infections.  

What is the mechanism of action of Clarithromycin? 

Clarithromycin works by stopping bacteria from making proteins, which prevents them from growing and multiplying, helping the body clear the infection. 

Who should not take Clarithromycin? 

Clarithromycin should not be taken by people who are allergic to it or similar antibiotics, have liver problems, certain heart rhythm issues, low potassium/magnesium levels, or are pregnant/breastfeeding unless approved by a doctor. People taking interacting medicines should also consult their doctor first. 

Reference 

1. PubChem. Clarithromycin [Internet]. pubchem.ncbi.nlm.nih.gov. Available from 
2. https://www.facebook.com/Drugscom. Clarithromycin Dosage Guide + Max Dose, Adjustments [Internet]. Drugs.com. 2023. Available from 
3. Clarithromycin (Oral Route) Description and Brand Names – Mayo Clinic [Internet]. www.mayoclinic.org. Available from 

Pranathi Chintaluri

Pranathi is a final year Pharm D student at Chalapathi Institute of Pharmaceutical Sciences. She loves learning and applying her knowledge in pharmacy and has a passion for writing, which allows her to express ideas clearly and creatively. She enjoys combining her technical skills with her love for writing and communication to make a meaningful impact. Currently she is working on a research paper about “Consanguineous marriages and its impact on children’s health” which will be published by the end of 2025.