Clarith

Clarith Tablet, which contains the active ingredient Clarithromycin, is an antibiotic used to treat various bacterial infections.

Uses of Clarith Tablet

Clarith Tablet is prescribed for:

• Respiratory Tract Infections: This includes conditions such as pharyngitis, tonsillitis, acute maxillary sinusitis, acute bacterial exacerbation of chronic bronchitis, pneumonia, and legionellosis.
• Skin and Soft Tissue Infections: It effectively treats various infections affecting the skin and underlying tissues.
• Other Specific Infections: This covers peptic ulcer disease (often as part of a combination therapy for Helicobacter pylori), leprosy, Lyme disease, and acne.

Dosage Information

The dosage of Clarith Tablet varies depending on the type of infection, age, and individual patient factors. It can be taken orally, intravenously, or applied topically.

Adult Dosing

Oral Administration:

• Acute Exacerbation of Chronic Bronchitis:
  • Standard Release: 250-500 mg every 12 hours for 7-14 days.
  • Extended Release: 1000 mg once daily for 7 days.
• Mycobacterial Infection (Prophylaxis and Treatment): 500 mg every 12 hours for 7-14 days, often used in combination with other antimycobacterial drugs (e.g., rifampin, ethambutol).
• Peptic Ulcer Disease: 500 mg every 8-12 hours for 10-14 days. This is typically part of a 2- or 3-drug regimen with agents like bismuth subsalicylate, amoxicillin, H2 receptor antagonists, or proton pump inhibitors.
• Pharyngitis, Tonsillitis: 250 mg every 12 hours for 10 days.
• Community-Acquired Pneumonia, Skin/Skin Structure Infection:
  • Standard Release: 250 mg every 12 hours for 7-14 days.
  • Extended Release: 1000 mg once daily for 7 days.
• Endocarditis Prophylaxis: 500 mg orally 30-60 minutes before a surgical procedure.

Intravenous (IV) Administration:

• Respiratory Tract Infections; Skin and Soft Tissue Infections; Susceptible Infections: 500 mg twice daily for 2-5 days, infused over 60 minutes using a 0.2% solution. Transition to oral therapy as soon as possible.

Topical Administration:

• Apply a thin layer to the affected area once daily.

Child Dosing

• Oral Administration: 15 mg/kg/day, divided and given every 12 hours, with a maximum dose of 1 gram per day.

Renal Impairment

• For patients with a creatinine clearance (CrCl) less than 30 ml/min, the dosage should be halved, or the dosing interval should be doubled.

Administration Guidelines

• Standard release tablets and oral suspension: Can be taken with or without food.
• Extended-release (XL) and modified-release (MR) tablets: Should be taken with food. Swallow these tablets whole; do not chew or crush them.

Important Considerations

Contraindications

Do not use Clarith Tablet if you have:

• Known hypersensitivity to clarithromycin or other macrolide antibiotics.
• Are taking certain medications, including terfenadine, astemizole, pimozide, cisapride, or ergot derivatives, due to potentially fatal drug interactions.
• Are pregnant or have a history of acute porphyria.

Precautions

Use with caution in patients with:

• Renal and hepatic impairment.
• Known macrolide cross-resistance.
• Lactation: The drug is excreted in breast milk, so use with caution.
• Children.

Drug Interactions

Clarith Tablet can interact with many medications, potentially leading to altered drug effectiveness or increased side effects. Key interactions include:

• Reduced efficacy with CYP3A inducers (e.g., phenytoin, carbamazepine, efavirenz, rifampicin).
• Increased levels and risk of toxicity with:
  • Ritonavir (inhibition of metabolism).
  • Quinidine or disopyramide (risk of Torsades de pointes).
  • Phosphodiesterase inhibitors (sildenafil, tadalafil, vardenafil).
  • Digoxin.
  • Atazanavir, itraconazole, or saquinavir (bi-directional interactions).
  • Verapamil (risk of hypotension, bradyarrhythmias, lactic acidosis).
  • HMG-CoA reductase inhibitors (e.g., statins, increased risk of myopathy/rhabdomyolysis).
  • Oral hypoglycemic drugs (e.g., pioglitazone) and insulin (increased risk of hypoglycemia).
  • Oral anticoagulants (risk of serious hemorrhage, elevated INR/prothrombin time).
  • Aminoglycosides (increased ototoxicity).
  • Triazolobenzodiazepines (e.g., midazolam, increased and prolonged sedation).
• Potentially Fatal Interactions: Avoid concurrent use with ergot alkaloids (e.g., ergotamine, dihydroergotamine) due to acute ergot toxicity, and with astemizole, cisapride, pimozide, or terfenadine due to risk of QT prolongation and serious ventricular arrhythmias.

Adverse Effects

Common side effects often involve the gastrointestinal system. Seek medical attention if you experience severe or unusual side effects.

Common ( $>1\%$):

• Gastrointestinal effects (general, 13%)
• Abnormal taste (3-7%)
• Diarrhea (3-6%)
• Nausea (3-6%)
• Vomiting (1-6%)
• Abdominal pain (2-3%)
• Elevated blood urea nitrogen (BUN) (4%)
• Rash (children, 3%)
• Dyspepsia (2%)
• Heartburn (2%)
• Headache (2%)
• Elevated prothrombin time (PT) (1%)

Less Common ($<1\%$):

• Anaphylaxis, anorexia, anxiety, Clostridium difficile colitis, dizziness, dyspnea, elevated liver function tests, glossitis, hallucinations, hepatic dysfunction, hepatitis, hypoglycemia, increased alkaline phosphatase, increased aspartate aminotransferase, increased bilirubin, increased serum creatinine, jaundice, leukopenia, manic behavior, neuromuscular blockade, neutropenia, pancreatitis, psychosis, QT prolongation, seizures, Stevens-Johnson syndrome, thrombocytopenia.

Topical Application Side Effects:

• Dryness, irritation, itching, peeling, redness, swelling of the skin.

Potentially Fatal Adverse Effects:

• Pseudomembranous colitis, anaphylaxis, Stevens-Johnson syndrome.

Mechanism of Action

Clarithromycin inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit of susceptible organisms. It is active against various bacteria, including susceptible streptococci, staphylococci, B. catarrhalis, L. spp, C. trachomatis, and U. urealyticum.

Manufacturer Information

Clarith 500mg Tablet is manufactured by Time Pharmaceuticals Pvt. Ltd. Its generic name is Clarithromycin, and it is available in Nepal.

Disclaimer: This information is for general knowledge and informational purposes only and does not constitute medical advice. It is not intended to be a substitute for professional medical judgment, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.