Overview
11 DESCRIPTION Azithromycin tablets USP contain the active ingredient azithromycin, a macrolide antibacterial drug, for oral administration. Azithromycin has the chemical name (2R,3S,4R,5R,8R,10R,11R,12S,13S,14R)-13-[(2,6-dideoxy-3-C-methyl-3-O-methyl-α-L-ribo-hexopyranosyl)oxy]-2-ethyl-3,4,10-trihydroxy-3,5,6,8,10,12,14-heptamethyl-11-[[3,4,6-trideoxy-3-(dimethylamino)-β-D-xylo-hexopyranosyl]oxy]...
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Azithromycin is a macrolide antibacterial drug. [see ] 12.2 Pharmacodynamics Based on animal models of infection, the antibacterial activity of azithromycin appears to correlate with the ratio of area under the concentration-time curve to minimum inhibitory concentration (AUC/MIC) for certain pathogens ( S. pneumoniae and S. aureus ). The principal pharmacokinetic/pharmacodynamic parameter best associated with clinical and microbiological cure has not been elucidated in clinical trials with azithromycin. Cardiac Electrophysiology QTc interval prolongation was studied in a randomized, placebo-controlled parallel trial in 116 healthy subjects who received either chloroquine (1000 mg) alone or in combination with oral azithromycin (500 mg,...
Indications
- 1 INDICATIONS AND USAGE Azithromycin is a macrolide antibacterial drug indicated for the treatment of patients with mild to moderate infections caused by susceptible strains of the designated microorganisms in the specific conditions listed below. Recommended dosages and durations of therapy in adult and pediatric patient populations vary in these indications. [see Dosage and Administration (2) ] Azithromycin is a macrolide antibacterial drug indicated for mild to moderate infections caused by designated, susceptible bacteria: • Acute bacterial exacerbations of chronic bronchitis in adults ()...
Common Doses
- 500 mg
- 250 mg
- 30 mg
- 10 mg
Dosage
2 DOSAGE AND ADMINISTRATION • Adult Patients ( ) Infection Recommended Dose/Duration of Therapy Community-acquired pneumonia (mild severity) Pharyngitis/tonsillitis (second-line therapy) Skin/skin structure (uncomplicated) 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5. Acute bacterial exacerbations of chronic bronchitis (mild to moderate) 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5 or 500 mg once daily for 3 days. Acute bacterial sinusitis 500 mg once daily for 3 days.
Contraindications
- 4 CONTRAINDICATIONS • Patients with known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide drug. () • Patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin. () 4.1 Hypersensitivity Azithromycin tablets are contraindicated in patients with known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide drug. 4.2 Hepatic Dysfunction Azithromycin tablets are contraindicated in patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin.
Side Effects
- 6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in labeling: • Hypersensitivity [see ] • Hepatotoxicity [see ] • Infantile Hypertrophic Pyloric Stenosis (IHPS) [see ] • QT Prolongation [see Warnings and Precautions (5.4) ] • Cardiovascular Death [see ] • Clostridioides difficile- Associated Diarrhea (CDAD) [see ] • Exacerbation of Myasthenia Gravis [see ] Most common adverse reactions are diarrhea (5 to 14%), nausea (3 to 18%), abdominal pain (3 to 7%), or vomiting (2 to 7%).
Interactions
- 7 DRUG INTERACTIONS • Nelfinavir: Close monitoring for known adverse reactions of azithromycin, such as liver enzyme abnormalities and hearing impairment, is warranted. () • Warfarin: Use with azithromycin may increase coagulation times; monitor prothrombin time. () 7.1 Nelfinavir Co-administration of nelfinavir at steady-state with a single oral dose of azithromycin resulted in increased azithromycin serum concentrations.