Clarith125 mg/5 ml

Clarith 125 mg/5 ml is a macrolide antibiotic used to treat a range of bacterial infections. Its indications can be classified by strength of evidence as follows:

Established / FDA-approved uses

• Acute bacterial exacerbation of chronic bronchitis
• Community-acquired pneumonia (mild to moderate)
• Acute maxillary sinusitis
• Pharyngitis and tonsillitis (as an alternative in penicillin-allergic patients)
• Uncomplicated skin and skin-structure infections
• Acute otitis media in children
• Mycobacterium avium complex (MAC) disease - treatment and prevention, in HIV-infected and other immunocompromised patients

Uses requiring combination therapy

• Helicobacter pylori eradication in patients with active or past duodenal ulcer disease, given together with a proton pump inhibitor (e.g. omeprazole or lansoprazole) and amoxicillin (triple therapy)

Guideline-supported / commonly used off-label uses

• Odontogenic (dental) infections, as an alternative agent
• Component of combination regimens for non-tuberculous mycobacterial infections other than MAC

Clarith 125 mg/5 ml should be used only for infections proven or strongly suspected to be caused by susceptible bacteria, as directed by a physician.

Each formulation of Clarith 125 mg/5 ml contains Clarith 125 mg/5 ml as the active pharmaceutical ingredient. It is commercially available as:

• Film-coated tablets (immediate-release), commonly 250 mg and 500 mg
• Extended-release tablets, commonly 500 mg
• Granules for oral suspension (125 mg/5 mL after reconstitution)
• Powder for solution for intravenous infusion (500 mg/vial)

Exact strength, formulation, and inactive ingredients vary by manufacturer and product; always check the specific product label.

Clarith 125 mg/5 ml is a semi-synthetic macrolide antibiotic derived from erythromycin. It differs structurally by methylation of a hydroxyl group, which improves acid stability, oral bioavailability, and tissue penetration compared with erythromycin, while retaining a similar spectrum of activity.

Clarith 125 mg/5 ml is active against many gram-positive bacteria, some gram-negative organisms, atypical pathogens (such as Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella species), and certain mycobacteria, including Mycobacterium avium complex.

Macrolide antibiotic

Mechanism of action

Clarith 125 mg/5 ml inhibits bacterial protein synthesis by binding to the 23S ribosomal RNA of the 50S subunit of susceptible bacterial ribosomes, blocking the transpeptidation and translocation steps of protein synthesis. Depending on the organism and drug concentration, its action may be bacteriostatic or bactericidal.

Pharmacokinetics

• Absorption: Well absorbed orally; food modestly delays but does not significantly reduce absorption of immediate-release tablets.
• Metabolism: Extensively metabolized in the liver via CYP3A4, producing the microbiologically active metabolite 14-hydroxyClarith 125 mg/5 ml.
• Elimination: Eliminated renally and hepatically; elimination half-life is dose-dependent, approximately 3-7 hours for the parent drug.

Because Clarith 125 mg/5 ml is both a substrate and a moderate-to-strong inhibitor of CYP3A4, it has significant potential for drug-drug interactions (see Interactions).

• Clarith 125 mg/5 ml immediate-release tablets and oral suspension may be taken with or without food.
• Clarith 125 mg/5 ml extended-release tablets should be taken with food and swallowed whole; do not crush, chew, or split.
• Shake the oral suspension well before each dose and use an appropriate measuring device.
• Try to take doses at evenly spaced intervals (e.g. every 12 hours) to maintain consistent blood levels.
• Complete the full prescribed course of Clarith 125 mg/5 ml even if symptoms improve before finishing the medicine.

Clarith 125 mg/5 ml is a moderate-to-strong inhibitor of CYP3A4 and has clinically significant interactions with a number of drugs.

Interactions requiring avoidance/contraindication

• Statins (simvastatin, lovastatin): Markedly increased statin levels, raising the risk of myopathy and rhabdomyolysis - concurrent use is contraindicated. Other statins (e.g. atorvastatin, rosuvastatin) require caution and dose limitation.
• Colchicine: In patients with renal or hepatic impairment, co-administration can cause life-threatening or fatal colchicine toxicity due to CYP3A4/P-glycoprotein inhibition; this combination should be avoided in such patients.
• Ergot alkaloids (ergotamine, dihydroergotamine): Risk of acute ergot toxism (peripheral vasospasm, ischemia) - contraindicated.
• Cisapride, pimozide, lurasidone, lomitapide: Risk of serious cardiac arrhythmias or other toxicity due to elevated plasma levels - contraindicated.

Interactions requiring caution/monitoring

• QT-prolonging drugs (certain antiarrhythmics, antipsychotics, other QT-prolonging agents): Additive risk of QT prolongation and torsades de pointes.
• Oral anticoagulants (e.g. warfarin): Increased anticoagulant effect and bleeding risk; monitor INR.
• Calcium channel blockers (e.g. verapamil, amlodipine): Risk of hypotension, bradyarrhythmias, and acute kidney injury.
• Digoxin: Increased digoxin levels; monitor for toxicity.
• Benzodiazepines (e.g. midazolam, triazolam): Increased sedation and psychomotor impairment.
• Theophylline, carbamazepine, cyclosporine, tacrolimus: Increased plasma levels with risk of toxicity; monitoring recommended.
• Strong CYP3A4 inducers (rifampin, phenytoin, carbamazepine): May reduce Clarith 125 mg/5 ml concentrations and effectiveness.

Always inform your physician or pharmacist of all medicines, supplements, and herbal products being taken before starting Clarith 125 mg/5 ml.

As with all medicines, Clarith 125 mg/5 ml can cause side effects, though not everyone experiences them.

Common side effects

• Nausea, vomiting, abdominal pain
• Diarrhea
• Altered taste (metallic or bitter taste - dysgeusia)
• Headache

Less common side effects

• Stomatitis, glossitis, oral candidiasis
• Dizziness, insomnia, anxiety
• Skin rash

Serious side effects (seek medical attention promptly)

• Signs of an allergic reaction: rash, hives, swelling of the face/throat, difficulty breathing
• Signs of liver problems: yellowing of skin/eyes, dark urine, severe fatigue, loss of appetite
• Severe or persistent diarrhea (possible Clostridioides difficile-associated diarrhea)
• Palpitations, fainting, or irregular heartbeat (possible QT prolongation/arrhythmia)
• Muscle pain, tenderness, or weakness (possible rhabdomyolysis, especially with statins)

Rare postmarketing reports include tooth/tongue discoloration, hearing loss (usually reversible), and psychiatric disturbances.

Pregnancy

Clarith 125 mg/5 ml is not recommended for use during pregnancy except in situations where no alternative therapy is appropriate, and only if the potential benefit justifies the potential risk to the fetus. Use in pregnancy should occur only after consultation with a physician, who will weigh the risks and benefits for the specific clinical situation.

Lactation

Clarith 125 mg/5 ml and its active metabolite pass into human breast milk in small amounts. A nursing infant should be monitored for possible effects (such as diarrhea or thrush) if the mother is taking Clarith 125 mg/5 ml. Use during breastfeeding only on the advice of a physician.

Before starting Clarith 125 mg/5 ml, inform your physician of any heart, liver, kidney, or neuromuscular conditions, and all other medicines being taken.

QT prolongation

Clarith 125 mg/5 ml can prolong the QT interval, which may lead to serious ventricular arrhythmias. Avoid use in patients with known QT prolongation, ventricular arrhythmia, uncorrected hypokalemia or hypomagnesemia, significant bradycardia, or concurrent use of other QT-prolonging drugs. Use with caution in the elderly and in patients with cardiac disease.

Hepatotoxicity

Cases of hepatic dysfunction, including hepatocellular and/or cholestatic hepatitis (rarely with hepatic failure), have been reported. Discontinue Clarith 125 mg/5 ml immediately if signs or symptoms of hepatitis occur (e.g. jaundice, dark urine, anorexia).

Clostridioides difficile-associated diarrhea

Clarith 125 mg/5 ml, like nearly all antibiotics, can cause C. difficile-associated diarrhea, ranging from mild diarrhea to fatal colitis. Evaluate if diarrhea occurs during or after treatment.

Myasthenia gravis

Clarith 125 mg/5 ml may worsen symptoms of myasthenia gravis; use with caution and close monitoring in these patients.

Drug interactions

See Interactions for clinically significant combinations, including contraindicated combinations with certain statins, colchicine, and ergot alkaloids.

Antibiotic stewardship

Take Clarith 125 mg/5 ml exactly as prescribed by your physician; do not stop, extend, skip doses, or share this medicine with others without medical advice. Inappropriate use can contribute to antibiotic resistance and treatment failure.

Overdose of Clarith 125 mg/5 ml may cause gastrointestinal symptoms such as nausea, vomiting, and diarrhea. There is a case report of altered mental status, paranoid behavior, and hypokalemia with overdose.

If an overdose is suspected, seek immediate medical attention or contact emergency services/a poison control center right away. Treatment is supportive; unabsorbed drug should be removed by appropriate measures under medical supervision (e.g. gastric evacuation). Hemodialysis and peritoneal dialysis are not expected to significantly lower serum levels of Clarith 125 mg/5 ml. Do not attempt to manage a suspected overdose at home without medical guidance.

Store Clarith 125 mg/5 ml tablets and capsules at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

Reconstituted oral suspension should be stored at room temperature (not refrigerated) and used within 14 days; discard any unused portion after that time.

Renal impairment

In patients with creatinine clearance below 30 mL/min, reduce the dose or dosing frequency of Clarith 125 mg/5 ml by approximately half, as directed by the physician.

Hepatic impairment

Use Clarith 125 mg/5 ml with caution in hepatic impairment, particularly when renal function is also reduced; monitor liver function.

Elderly

Older patients may be at greater risk of QT prolongation and drug interactions; renal function should be assessed and dosing adjusted as needed.

Pediatric patients

See Pediatric Uses for age-specific dosing information.

Pregnancy and lactation

See Pregnancy and Lactation section.

Duration of treatment with Clarith 125 mg/5 ml depends on the indication and typically ranges from 7 to 14 days for most respiratory tract, skin, and soft tissue infections. H. pylori eradication regimens are usually given for 10-14 days. Treatment or prophylaxis of mycobacterial infections (e.g. MAC) may require prolonged therapy as part of combination regimens, guided by the treating physician. The full course should always be completed as prescribed, even if symptoms resolve earlier.

Clarith 125 mg/5 ml granules for oral suspension require reconstitution before use. Add the amount of water specified on the label in two portions, shaking well after each addition, to produce a suspension containing 125 mg/5 mL (or the labeled strength). Shake well before each dose. The reconstituted suspension should be stored at room temperature (not refrigerated) and discarded after 14 days.

Clarith 125 mg/5 ml belongs to the macrolide class of antibiotics, which also includes erythromycin and azithromycin. Macrolides share a common mechanism of inhibiting bacterial protein synthesis at the 50S ribosomal subunit.

Clarith 125 mg/5 ml binds reversibly to the 23S ribosomal RNA of the 50S subunit of the bacterial ribosome, inhibiting the translocation step of protein synthesis. This blocks bacterial growth and, depending on the organism and concentration achieved, may be bacteriostatic or bactericidal.

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Clarith 125 mg/5 ml is approved for use in pediatric patients for indications such as pharyngitis/tonsillitis, acute otitis media, community-acquired pneumonia, and uncomplicated skin infections, generally in children who can take the oral suspension.

The usual pediatric dose is 15 mg/kg/day divided every 12 hours, generally for 10 days, depending on indication, up to adult dosing limits.

Safety and efficacy of Clarith 125 mg/5 ml in children below 6 months of age have not been established. Extended-release tablets are not recommended for use in children under 12 years of age.