Klaricid

# Klaricid ## Overview - **Classification**: Macrolide antibiotic - **Mechanism**: Inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. This leads to a bacteriostatic effect. ## Primary Indications 1. **Respiratory Tract Infections**: Pharyngitis, tonsillitis, acute sinusitis, bronchitis, community-acquired pneumonia. 2. **Skin and Skin Structure Infections**: Uncomplicated infections. 3. **Mycobacterial Infections**: Disseminated Mycobacterium avium complex (MAC). 4. **H. pylori Eradication**: As part of multi-drug regimens for peptic ulcer disease. ## Adult Dosing ### Standard Dosing **Respiratory/Skin & Skin Structure Infections** - **Dose**: **250 mg** or **500 mg** - **Frequency**: Every **12 hours (Q12H)** - **Route**: Oral - **Duration**: 7 to 14 days **H. pylori Eradication** (as part of triple therapy, e.g., with PPI + amoxicillin/metronidazole) - **Dose**: **500 mg** - **Frequency**: Every **12 hours (Q12H)** - **Route**: Oral - **Duration**: 10 to 14 days **Disseminated Mycobacterium avium complex (MAC)** - **Dose**: **500 mg** - **Frequency**: Every **12 hours (Q12H)** - **Route**: Oral - **Duration**: Lifelong or until immune reconstitution (e.g., CD4 >100 cells/mm³ for 6 months). ### Dose Adjustments - **Renal Impairment**: For CrCl < 30 mL/min, reduce dose by **50%** or extend dosing interval (e.g., **250 mg Q12H** or **500 mg Q24H**). - **Hepatic Impairment**: Use with caution. No adjustment needed for mild-moderate hepatic impairment. Avoid in severe hepatic dysfunction with renal impairment. - **Elderly Patients**: No specific adjustment needed, but monitor renal function carefully. ## Pediatric Dosing ### Neonates (0-28 days) - **Dose**: Not recommended due to limited data and potential risk of hypertrophic pyloric stenosis. - **Special Notes**: Consider alternative antibiotics in this age group. ### Infants (1-12 months) - **Indication**: Otitis media, pharyngitis, pneumonia, skin infections. - **Dose**: **7.5 mg/kg/dose** - **Frequency**: Every **12 hours (Q12H)** - **Maximum**: **500 mg/dose** - **Special Notes**: Use oral suspension; accurately measure dose. ### Children (1-12 years) - **Indication**: Otitis media, pharyngitis, pneumonia, skin infections, MAC. - **Dose**: **7.5 mg/kg/dose** - **Frequency**: Every **12 hours (Q12H)** - **Maximum**: **500 mg/dose** (equivalent to adult **1000 mg/day**). - **Special Notes**: Oral suspension is commonly used. Duration typically 5-10 days, or longer for MAC (e.g., 15 mg/kg/day divided Q12H for MAC, max 1000 mg/day). ### Adolescents (13-18 years) - **Dose**: Generally follows adult dosing guidelines. - **Frequency**: Every **12 hours (Q12H)** - **Maximum**: **500 mg/dose** (or **1000 mg/day**). - **Special Notes**: May use adult formulations (tablets) if able to swallow. ## Safety Information ### Contraindications - **Absolute**: Hypersensitivity to clarithromycin or other macrolides. - **Absolute**: Co-administration with **pimozide, cisapride, ergotamine, dihydroergotamine, ticagrelor, ranolazine**. - **Absolute**: Co-administration with **lovastatin** or **simvastatin** due to rhabdomyolysis risk. - **Absolute**: Co-administration with **colchicine** in patients with renal or hepatic impairment. - **Absolute**: History of QT prolongation or ventricular arrhythmia. - **Absolute**: Severe hepatic impairment in combination with renal impairment. ### Common Adverse Effects - **Very Common (>10%)**: Dysgeusia (taste disturbance). - **Common (1-10%)**: Nausea, vomiting, diarrhea, abdominal pain, dyspepsia, headache, insomnia. - **Serious but Rare**: QT prolongation, Torsades de Pointes, C. difficile-associated diarrhea (CDAD), hepatotoxicity, rhabdomyolysis, Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN). ### Key Drug Interactions - **CYP3A4 Substrates**: Potent inhibitor of CYP3A4. Increases levels of **statins (simvastatin, lovastatin)**, **colchicine**, **warfarin**, **oral contraceptives**, **carbamazepine**, **digoxin**, **sirolimus**, **tacrolimus**, **theophylline**, **benzodiazepines (midazolam, triazolam)**, **calcium channel blockers (verapamil, amlodipine)**. - **QT-prolonging Drugs**: Concurrent use with other QT-prolonging agents (e.g., antiarrhythmics, antipsychotics) increases risk of QT prolongation and Torsades de Pointes. - **P-glycoprotein Inhibitors**: May increase absorption of P-gp substrates, e.g., **digoxin**. - **Ergot Alkaloids**: May lead to acute ergot toxicity (vasospasm, ischemia of extremities). ## Monitoring & Follow-up - **Before Treatment**: Assess renal and hepatic function. Consider baseline ECG if risk factors for QT prolongation exist. - **During Treatment**: Monitor for signs of C. diff infection (severe diarrhea). Monitor LFTs if prolonged therapy or symptoms of hepatotoxicity. Monitor electrolytes if risk of QT prolongation. - **Clinical Signs**: Watch for allergic reactions (rash, angioedema), severe abdominal pain, dark urine/jaundice, muscle pain/weakness (if on statin). ## Clinical Pearls - 💡 **Taste Disturbance**: A metallic/bitter taste is common. Taking with food may help but does not eliminate it. - 💡 **GI Upset**: Can cause significant GI upset; taking with food may help reduce symptoms. - 💡 **Drug Interactions**: Clarithromycin has a very extensive drug interaction profile. Always check for interactions with all concomitant medications. - 💡 **Cardiovascular Risk**: Due to potential QT prolongation, clarify patient history of cardiac conditions and other QT-prolonging drugs. - 💡 **Suspension**: Oral suspension should not be refrigerated as it can thicken. Store at room temperature. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.