Infectious Disease Compendium

Azithromycin (Zithromax®)

Dosing

CrCl Formula

CrCl > 80: 250-500 mg qd iv or po.

CrCl 80-50: 250-500 mg qd iv or po.

CrCl 50-10: 250-500 mg qd iv or po.

CrCl < 10: 250-500 mg qd iv or po.

Hemodialysis 250-500 mg qd iv or po.

Peritoneal dialysis: 250-500 mg qd iv or po.

Important side effects

Important side effects

Death. In people who are taking it for mostly sinusitis and bronchitis, there is an increase risk of death, espcially if there is underlying cardiac disease:

"...estimated 47 additional cardiovascular deaths per 1 million courses; patients in the highest decile of risk for cardiovascular disease had an estimated 245 additional cardiovascular deaths per 1 million courses." compared to amoxicillin (PubMed).

It is safe in the young with no cardiac issues (PubMed) (PubMed).

Important drug interactions

Avoid aluminum-and magnesium-containing antacids. Aluminum carbonate, aluminum hydroxide, aluminum phosphate, amiodarone, carbamazepine, cyclosporine, digoxin, dihydroxyaluminum aminoacetate, dihydroxyaluminum sodium carbonate, disopyramide, ergot derivatives, fentanyl, hexobarbital, magnesium carbonate, magnesium hydroxide, magnesium oxide, magnesium trisilicate, nelfinavir, phenytoin, pimozide, rifabutin, theophylline, triazolam, warfarin.

Rants and Screeds

So many drugs have 'max' in the name. I need to trademark maxmaxmax. It has the requisite bunch of 'x's' needed in a modern drug. Too bad Omnimax® is taken.

Pearls

Treatment of choice

WITH a beta lactam for empiric therapy of community acquired pneumonia; MAI prophylaxis: 1250 mg q week.

Use for

Acute mild to moderate exacerbations of COPD: either 500 mg po per day for 3 days OR 500 mg on day one, 250 mg/day on days 2-5

Acute bacterial sinusitis: 500 mg po daily for 3 days.

Cervicitis due to Chlamydia trachomatis: single 1 gram dose po. Cervicitis due to Neisseria gonorrhoeae: single 2 gram dose po. Cellulitis (uncomplicated): 500 mg po on day one, 250 mg/day on days 2-5.

Chancroid (Haemophilus ducreyi): single 1 gram dose.

MAI, prevention: 1200 mg po once weekly (may ethambutol combined with rifabutin). MAI, treatment: 600 mg po every day with ethambutol 15 mg/kg/day.

Pharyngitis (second-line therapy): 500 mg po on day one, 250 mg/day on days 2-5. Pneumonia, community-acquired (mild): 500 mg po on day 1, 250 mg/day on days 2-5.

Urethritis due to Chlamydia trachomatis: single 1 gram dose po.

Urethritis due to Neisseria gonorrhoeae: single 2 gram dose po. PID: 500 mg IV qd for at least 2 days, followed by 250 mg po qd x 7 days.

Pneumonia, community-acquired: 500 mg IV every day for minimum 2 days, then 500 mg po qd for 7-10 days.

Legionella, Mycoplasm.

Don't use for

Class

Macrolide.