Overview
11 DESCRIPTION Clarithromycin is a semi-synthetic macrolide antimicrobial for oral use. Chemically, it is 6- 0 ‑ methylerythromycin. The molecular formula is C 38 H 69 NO 13 , and the molecular weight is 747.96. The structural formula is: Clarithromycin is a white to off-white crystalline powder.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Clarithromycin is a macrolide antimicrobial drug [see Microbiology ( 12.4 )] . 12.3 Pharmacokinetics Absorption Clarithromycin Tablets The absolute bioavailability of 250 mg clarithromycin tablets was approximately 50%. For a single 500 mg dose of clarithromycin, food slightly delays the onset of clarithromycin absorption, increasing the peak time from approximately 2 to 2.5 hours. Food also increases the clarithromycin peak plasma concentration by about 24%, but does not affect the extent of clarithromycin bioavailability.
Indications
- 1 INDICATIONS AND USAGE Clarithromycin is a macrolide antimicrobial indicated for mild to moderate infections caused by designated, susceptible bacteria in the following: Acute Bacterial Exacerbation of Chronic Bronchitis in Adults ( 1.1 ) Acute Maxillary Sinusitis ( 1.2 ) Community-Acquired Pneumonia ( 1.3 ) Pharyngitis/Tonsillitis ( 1.4 ) Uncomplicated Skin and Skin Structure Infections ( 1.5 ) Acute Otitis Media in Pediatric Patients ( 1.6 ) Treatment and Prophylaxis of Disseminated Mycobacterial Infections ( 1.7 ) Helicobacter pylori Infection and Duodenal Ulcer Disease in Adults ( 1.
Common Doses
- 250 mg
- 500 mg
- 15 mg
- 7.5 mg
Dosage
2 DOSAGE AND ADMINISTRATION Adults : clarithromycin tablets 250 mg or 500 mg every 12 hours for 7 to 14 days ( 2.2 ) H. pylori eradication (in combination with lansoprazole/amoxicillin, omeprazole/amoxicillin, or omeprazole): clarithromycin tablets 500 mg every 8 or 12 hours for 10 to 14 days. See full prescribing information (FPI) for additional information. ( 2.3 ) Pediatric Patients : clarithromycin 15 mg/kg/day divided every 12 hours for 10 days ( 2.4 ) Mycobacterial Infections : clarithromycin tablets 500 mg every 12 hours; clarithromycin tablets 7.
Contraindications
- 4 CONTRAINDICATIONS Hypersensitivity to clarithromycin or any macrolide drug ( 4.1 ) Cisapride and pimozide ( 4.2 ) History of cholestatic jaundice/hepatic dysfunction with use of clarithromycin ( 4.3 ) Colchicine in renal or hepatic impairment ( 4.4 ) Lomitapide, lovastatin, and simvastatin ( 4.5 ) Ergot alkaloids (ergotamine or dihydroergotamine) ( 4.6 ) Lurasidone ( 4.7 ) 4.1 Hypersensitivity Clarithromycin tablets are contraindicated in patients with a known hypersensitivity to clarithromycin, erythromycin, or any of the macrolide antibacterial drugs [see Warnings and Precautions ( 5.
Side Effects
- 6 ADVERSE REACTIONS The following serious adverse reactions are described below and elsewhere in the labeling: Acute Hypersensitivity Reactions [see Warnings and Precautions ( 5.1 )] QT Prolongation [see Warnings and Precautions ( 5.2 )] Hepatotoxicity [see Warnings and Precautions ( 5.3 )] Serious Adverse Reactions Due to Concomitant Use with Other Drugs [see Warnings and Precautions ( 5.4 )] Clostridium difficile Associated Diarrhea [see Warnings and Precautions ( 5.6 )] Exacerbation of Myasthenia Gravis [see Warnings and Precautions ( 5.
Interactions
- 7 DRUG INTERACTIONS Co-administration of clarithromycin tablets is known to inhibit CYP3A, and a drug primarily metabolized by CYP3A may be associated with elevations in drug concentrations that could increase or prolong both therapeutic and adverse effects of the concomitant drug. Clarithromycin tablets should be used with caution in patients receiving treatment with other drugs known to be CYP3A enzyme substrates, especially if the CYP3A substrate has a narrow safety margin (e.g., carbamazepine) and/or the substrate is extensively metabolized by this enzyme.