Clarithromycin is a semisynthetic 14-membered ring macrolide antibiotic. Clarithromycin binds to the 50S ribosomal subunit and inhibits RNA-dependent protein synthesis in susceptible organisms. Clarithromycin has been shown to eradicate gastric MALT (mucosa-associated lymphoid tissue) lymphomas, presumably due to the eradication of tumorigenic Helicobacter pylori infection. This agent also acts as a biological response modulator, possibly inhibiting angiogenesis and tumor growth through alterations in growth factor expression
Clarithromycin, a semisynthetic macrolide antibiotic derived from erythromycin, inhibits bacterial protein synthesis by binding to the bacterial 50S ribosomal subunit. Binding inhibits peptidyl transferase activity and interferes with amino acid translocation during the translation and protein assembly process. Clarithromycin may be bacteriostatic or bactericidal depending on the organism and drug concentration.
Mechanism of action of Clarithromycin
Clarithromycin is first metabolized to 14-OH clarithromycin, which is active and works synergistically with its parent compound. Like other macrolides, it then penetrates bacteria cell wall and reversibly binds to domain V of the 23S ribosomal RNA of the 50S subunit of the bacterial ribosome, blocking translocation of aminoacyl transfer-RNA and polypeptide synthesis. Clarithromycin also inhibits the hepatic microsomal CYP3A4 isoenzyme and P-glycoprotein, an energy-dependent drug efflux pump
Indications of Clarithromycin
- Dental Abscess
- Sinusitis
- Bronchitis
- Bacterial Endocarditis Prevention
- Follicular Lymphoma
- Helicobacter Pylori Infection
- Legionella Pneumonia
- Mycobacterium avium-intracellulare,
- Mycoplasma Pneumonia
- Nongonococcal Urethritis
- Otitis Media
- Pertussis
- Pharyngitis
- Pneumonia
- Skin and Structure Infection
- Skin or Soft Tissue Infection
- Strep Throat
- Tonsillitis/Pharyngitis
- Toxoplasmosis
- Upper Respiratory Tract Infection
- Acute Bacterial Exacerbation of Chronic Bronchitis
- Acute maxillary sinusitis
- Bacterial Infections
- Bartonellosis
- Community-Acquired Pneumonia
- Duodenal ulcer caused by helicobacter pylori
- Infective Endocarditis
- Lyme Disease
- Mycobacterial Infection
- Otitis Media (OM)
- Streptococcal Pharyngitis
- Streptococcal tonsillitis
- Uncomplicated skin and subcutaneous tissue bacterial infection
- Investigated for use/treatment in bacterial infection, pediatric indications, and pneumonia.
- You should not take clarithromycin if you are allergic to other macrolides or the ingredients in the tablets which include microcrystalline cellulose, croscarmelose sodium, magnesium stearate and povidon
- Clarithromycin should not be used in people with a history of cholestatic jaundice and/or liver dysfunction associated with prior clarithromycin use.
- or if you have hypokalaemia (low blood potassium)
- Use of clarithromycin with the following medications: cisapride, pimozide, astemizole, terfenadine, ergotamine, ticagrelor, ranolazine or dihydroergotamine is not recommended.
- It should not be used with colchicine in people with kidney or liver impairment.
- Concomitant use with cholesterol medications such as lovastatin or simvastatin.
- Hypersensitivity to clarithromycin or any component of the product, erythromycin, or any macrolide antibiotics.
- QT prolongation or ventricular cardiac arrhythmias, including torsade de pointes.
Contra-Indications of Clarithromycin
- Clostridium difficile infection
- Low amount of magnesium in the blood
- Low amount of potassium in the blood
- Myasthenia Gravis
- Coronary artery disease
- Rapid Ventricular Heartbeat
- Very Rapid Heartbeat – Torsades de Pointes
- Slow Heartbeat
- Prolonged QT interval on EKG
- Abnormal EKG with QT changes from Birth
- Inflammation of the Liver with Stoppage of Bile Flow
- Chronic kidney disease stage 3A (moderate)
- Chronic kidney disease stage 3B (moderate)
- Chronic kidney disease stage 5 (failure)
- Allergies to Macrolide Antibiotics
Dosage of Cethromycin
Strengths: 250 mg; 500 mg; 125 mg/5 mL; 250 mg/5 mL
Tonsillitis/Pharyngitis
- Immediate-release: 250 mg orally every 12 hours for 10 days
Sinusitis
- Immediate-release: 500 mg orally every 12 hours for 14 days
- Extended-release: 1000 mg orally every 24 hours for 14 days
Bronchitis
Immediate-release
- Due to H influenzae: 500 mg orally every 12 hours for 7 to 14 days
- Due to H parainfluenzae: 500 mg orally every 12 hours for 7 days
- Due to M catarrhalis or S pneumoniae: 250 mg orally every 12 hours for 7 to 14 days
Extended-release
- 1000 mg orally every 24 hours for 7 days
Pneumonia
Immediate-release
- Due to H influenzae: 250 mg orally every 12 hours for 7 days
- Due to S pneumoniae or Chlamydophila pneumoniae: 250 mg orally every 12 hours for 7 to 14 days
Extended-release
- 1000 mg orally every 24 hours for 7 days
Mycoplasma Pneumonia
Immediate-release
- 250 mg orally every 12 hours for 7 to 14 days
Extended-release
- 1000 mg orally every 24 hours for 7 days
Skin and Structure Infection
Immediate-release
- 250 mg orally every 12 hours for 7 to 14 days
Helicobacter pylori Infection
Triple therapy
- In combination with lansoprazole and amoxicillin: Clarithromycin 500 mg orally every 12 hours for 10 to 14 days
- In combination with omeprazole and amoxicillin: Clarithromycin 500 mg orally every 12 hours for 10 days
Dual therapy
- In combination with omeprazole: Clarithromycin 500 mg orally every 8 hours for 14 days
- In combination with ranitidine bismuth citrate: Clarithromycin 500 mg orally every 8 to 12 hours for 14 days
Bacterial Endocarditis Prophylaxis
American Heart Association (AHA) recommendations
- Immediate-release: 500 mg orally as a single dose 30 to 60 minutes before procedure
Legionella Pneumonia
Some experts recommend
- Immediate-release: 500 mg orally every 12 hours
Pertussis
US CDC recommendations
- Immediate-release: 500 mg orally every 12 hours for 7 days
Tonsillitis/Pharyngitis
Immediate-release
- 6 months or older: 7.5 mg/kg orally every 12 hours for 10 days
- Maximum dose: 500 mg/dose
Pediatric Dose for Sinusitis
Immediate-release
- 6 months or older: 7.5 mg/kg orally every 12 hours for 10 days
- Maximum dose: 500 mg/dose
Pediatric Dose for Pneumonia
Immediate-release
- 6 months or older: 7.5 mg/kg orally every 12 hours for 10 days
- Maximum dose: 500 mg/dose
Pediatric Dose for Otitis Media
Immediate-release
- 6 months or older: 7.5 mg/kg orally every 12 hours for 10 days
- Maximum dose: 500 mg/do
Side Effects of Clarithromycin
The most common
Common
- Swelling of the face, throat, eyes, hands, lips, ankles, feet, or lower legs
- Rash
- Hoarseness
- Difficulty swallowing or breathing
- Peeling or blistering skin
- Yellowing of the skin or eyes
- Extreme tiredness
- Lack of energy
- Loss of appetite
- Unusual bleeding or bruising
Less common
- Cough
- fever or chills
- hoarseness
- lower back or side pain
- painful or difficult urination
- fast or chaotic heartbeats
- skin reactions such as painful rash, red or purple spots on the skin, or blisters
- trouble breathing
- swelling of your face, lips, tongue, or throat
Rare
- Fever with or without chills
- nausea and vomiting
- severe stomach cramps and pain
- skin rash and itching
- stomach tenderness
- unusual bleeding or bruising
- watery and severe diarrhea, which may also be bloody
- yellow eyes or skin
Drug Interactions of Clarithromycin
Clarithromycin may interact with following drugs, supplements,& may change the efficasy of drugs
- Colchicine
- calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
- astemizole
- “azole” antifungals (e.g., itraconazole, ketoconazole, voriconazole)
- benzodiazepines (e.g., clonazepam, diazepam, lorazepam)
- loperamide
- losartan
- other macrolide antibiotics (e.g., azithromycin, erythromycin)
- medications used to treat diabetes (e.g., pioglitazone, rosiglitazone, repaglinide)
- metronidazole
- Simvastatin
- Lovastatin
- Atorvastatin
- Verapamil
- Amlodipine
- Diltiazem
Clarithromycin increases blood levels of sildenafil (Viagra, Revatio), tadalafil(Cialis, Adcirca), vardenafil (Levitra), theophylline (Theolair), and carbamazepine (Tegretol), which can increase the side effects of these drugs.Ritonavir (Norvir) and atazanavir (Reyataz) increase blood levels of clarithromycin.Efavirenz (Sustiva), nevirapine (Viramune), and rifampin (Rifadin) decrease blood levels of clarithromycin.
Itraconazole (Sporanox) and saquinavir (Invirase) may increase blood levels of clarithromycin, while clarithromycin increases blood levels of both drugs. Abnormal heartbeats may occur when clarithromycin is combined with some drugs, such as amiodarone (Cordarone), quinidine (Quinidex), amitriptyline(Elavil), fluconazole (Diflucan), citalopram (Celexa), trazodone (Oleptro), or disopyramide (Norpace).
Pregnancy & Lactation of Clarithromycin
Pregnancy
Clarithromycin should not be used during pregnancy, especially the first 3 months of pregnancy, unless there is no appropriate alternative therapy. If you become pregnant while taking this medication, contact your doctor.
Breast-feeding
This medication passes into breast milk. If you are a breastfeeding mother and are taking clarithromycin, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
References
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