Azithromycin Prophylaxis Guidelines

Primary Indications for Azithromycin Prophylaxis

• The Centers for Disease Control and Prevention recommends azithromycin as a preferred first-line prophylactic agent for disseminated MAC disease in HIV-infected adults and adolescents with CD4+ counts <50 cells/µL, without requiring culture confirmation before initiation 1, 2
• Clinical assessment to rule out active disseminated MAC is sufficient; blood cultures for MAC may be obtained if clinically warranted, but are not mandatory before starting prophylaxis 1, 3
• Azithromycin offers the advantage of no cytochrome P450 interactions, making it safer than clarithromycin when used with protease inhibitors or NNRTIs 3, 4
• The American Academy of Pediatrics and the Centers for Disease Control and Prevention recommend the same azithromycin regimens used for treatment for post-exposure prophylaxis without culture confirmation 5, 6
• Prophylaxis should be administered to all close contacts within 21 days of exposure, especially prioritizing infants <12 months, pregnant women in third trimester, and healthcare workers 5
• For adults: 500 mg on day 1, followed by 250 mg daily on days 2-5 5
• For infants and children ≥6 months: 10 mg/kg (maximum 500 mg) on day 1, followed by 5 mg/kg daily (maximum 250 mg) on days 2-5 5, 6
• Azithromycin may be considered for prophylaxis in HIV-infected patients with frequent recurrent serious bacterial respiratory infections, though caution is warranted regarding antimicrobial resistance 7, 4
• When administered for MAC prophylaxis, azithromycin confers additional protection against respiratory bacterial infections 1, 8

Special Considerations

• The European Respiratory Society recommends against the use of azithromycin in COVID-19 patients without bacterial co-infection, as it is not recommended for routine use in hospitalized COVID-19 patients in the absence of proven bacterial infection 9
• Bacterial co-infection occurs in <10% of COVID-19 patients, so empiric use contributes to antimicrobial resistance without benefit 9
• Obtain baseline ECG to assess QTc interval before initiating long-term azithromycin therapy 10
• Do not use azithromycin if QTc >450 ms (men) or >470 ms (women) due to risk of torsades de pointes 10
• Azithromycin should not be taken simultaneously with aluminum- or magnesium-containing antacids as they reduce absorption by 24% 10
• Unlike clarithromycin, azithromycin does not interact with the cytochrome P450 system, making it safer for concurrent use with many medications 3, 4