Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
AZITHROMYCIN vs AMIKIN
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Binds to the 50S ribosomal subunit of susceptible bacteria, inhibiting m RNA translation and thus protein synthesis. Exhibits concentration-dependent bactericidal activity.
Aminoglycoside antibiotic that binds to the 30S ribosomal subunit, causing misreading of m RNA and inhibition of protein synthesis.
Acute bacterial exacerbations of chronic obstructive pulmonary disease due to H. influenzae, M. catarrhalis, or S. pneumoniae,Acute bacterial sinusitis due to H. influenzae, M. catarrhalis, or S. pneumoniae,Community-acquired pneumonia due to C. pneumoniae, H. influenzae, M. pneumoniae, or S. pneumoniae,Pharyngitis/tonsillitis due to S. pyogenes,Uncomplicated skin and skin structure infections due to S. aureus, S. pyogenes, or S. agalactiae,Urethritis/cervicitis due to C. trachomatis or N. gonorrhoeae,Genital ulcer disease due to H. ducreyi,Acute otitis media due to H. influenzae, M. catarrhalis, or S. pneumoniae,Prevention of disseminated M. avium complex disease in advanced HIV infection,Pertussis (off-label)
Treatment of serious gram-negative bacterial infections,Infections caused by susceptible strains of Pseudomonas aeruginosa, Escherichia coli, Proteus, Klebsiella, Serratia, and Enterobacter
500 mg orally once daily for 3 days, or 500 mg IV once daily for at least 2 days followed by 500 mg orally to complete 7-10 days of therapy for community-acquired pneumonia. For other indications, typical adult dose is 500 mg orally on day 1 then 250 mg orally once daily on days 2-5.
15 mg/kg/day IV or IM divided every 8 to 12 hours; usual adult dose: 15 mg/kg/day
Terminal half-life of approximately 68 hours (range 35–96 h) after multiple doses, allowing once-daily dosing and a prolonged post-antibiotic effect.
2-3 hours in adults with normal renal function; prolonged to 30-90 hours in ESRD.
Primarily hepatic, not via cytochrome P450 system. Partially metabolized to inactive metabolites. Eliminated via biliary excretion and renal excretion (<15% unchanged).
Amikacin is not metabolized; it is excreted unchanged primarily by glomerular filtration.
Primarily biliary/fecal (approx. 50% unchanged); renal excretion accounts for about 12% of the dose.
Renal: >90% unchanged in urine via glomerular filtration; biliary/fecal: <1%.
7–51% (concentration-dependent); primarily binds to albumin.
0-10% (low binding to albumin).
31.1 L/kg (range 23–50 L/kg), indicating extensive tissue penetration and sequestration (e.g., WBCs, liver, lung).
0.25 L/kg in adults; higher in neonates and edema states (0.3-0.4 L/kg), indicating distribution into extracellular fluid.
Oral: 37–40% (fasting); food may decrease absorption by ~50%.
IM: 100% (complete absorption); oral: <1% (not absorbed).
No dose adjustment required for GFR ≥10 m L/min. For GFR <10 m L/min, caution advised; no specific dose recommendation, consider alternative agent.
GFR 30-59 m L/min: extend dosing interval to every 12-24 hours; GFR 15-29 m L/min: extend to every 24-48 hours; GFR <15 m L/min: extend to every 48-72 hours or consider peritonitis dosing; adjust based on serum levels
No dose adjustment required for mild to moderate hepatic impairment (Child-Pugh class A and B). Contraindicated in severe hepatic impairment (Child-Pugh class C).
No specific Child-Pugh based adjustments required; amikacin is minimally hepatically metabolized; monitor renal function as primary clearance route
For otitis media and community-acquired pneumonia: 10 mg/kg orally or IV on day 1 (max 500 mg), then 5 mg/kg (max 250 mg) once daily on days 2-5. For pharyngitis/tonsillitis: 12 mg/kg orally once daily for 5 days (max 500 mg/day).
Neonates: 15-20 mg/kg/day IV/IM every 12-24 hours depending on gestational age; Infants and children: 15-22.5 mg/kg/day divided every 8-12 hours; maximum 1.5 g/day
No specific dose adjustment required; use same dosing as younger adults. Monitor renal function due to age-related decline, but no modification needed unless severe renal impairment (Cr Cl <10 m L/min).
Start with lower initial doses based on renal function; monitor renal function and serum amikacin levels closely; usual initial dose reduction to 7.5 mg/kg every 12-24 hours based on estimated GFR
None.
Amikacin can cause nephrotoxicity and ototoxicity. The risk of nephrotoxicity is greater in patients with impaired renal function and those receiving high doses or prolonged therapy. Ototoxicity (both vestibular and auditory) can occur in patients with pre-existing renal damage and in those with normal renal function treated with higher doses or for longer periods than recommended.
Hepatotoxicity: hepatitis, cholestatic jaundice, hepatic necrosis, hepatic failure,QT prolongation and torsades de pointes (especially with concurrent use of other QT-prolonging agents, electrolyte abnormalities, bradycardia, or structural heart disease),Clostridioides difficile-associated diarrhea (CDAD),Aggravation of myasthenia gravis,Severe allergic reactions (angioedema, anaphylaxis, Stevens-Johnson syndrome),Infantile hypertrophic pyloric stenosis (IHPS) in neonates following oral azithromycin,Use in pregnancy: category B; avoid during breastfeeding due to potential for disruption of infant gut flora
Neurotoxicity (ototoxicity) and nephrotoxicity; neuromuscular blockade; respiratory paralysis; cross-allergenicity among aminoglycosides; monitoring of renal function and drug levels recommended.
Hypersensitivity to azithromycin, erythromycin, or any macrolide antibiotic,History of cholestatic jaundice or hepatic dysfunction associated with prior azithromycin use,Concurrent use with ergotamine or dihydroergotamine (possible ergot toxicity)
Hypersensitivity to amikacin or any aminoglycoside; history of ototoxicity with prior aminoglycoside use.
Food does not significantly affect absorption; can be taken with or without food. However, avoiding high-fat meals may reduce minor GI side effects. No known specific food interactions.
No significant food interactions. Maintain adequate hydration. Avoid alcohol as it may worsen side effects.
FDA Category B. No evidence of teratogenicity in animal studies; limited human data show no increased risk of major malformations. First trimester: No significant association with birth defects. Second/third trimester: No reported fetal harm from short-term use for infections like chorioamnionitis. Use only if clearly needed.
Amikacin is an aminoglycoside antibiotic. There are no adequate and well-controlled studies in pregnant women. Animal studies have shown evidence of fetal harm (e.g., nephrotoxicity, ototoxicity) at doses similar to or lower than human doses. Amikacin crosses the placenta. First trimester: Risk cannot be excluded; use only if clearly needed. Second and third trimesters: Potential for fetal nephrotoxicity and ototoxicity; avoid use unless necessary for serious infections. Risk category D (positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience).
Azithromycin is excreted into breast milk in low amounts. M/P ratio approximately 0.2-0.6. Relative infant dose estimated at 2-6% of maternal weight-adjusted dose. Generally considered compatible with breastfeeding; monitor infant for diarrhea or rash.
Amikacin is excreted into human breast milk in low concentrations. The milk-to-plasma (M/P) ratio is approximately 0.1-0.2. After intramuscular administration of 500 mg, peak milk concentrations are about 1-2 mcg/m L. Because of low oral bioavailability (poorly absorbed from the GI tract), systemic effects in the nursing infant are unlikely. However, theoretical risk of alteration of infant gut flora and direct exposure. Use with caution, especially in premature infants or those with renal impairment. The American Academy of Pediatrics considers amikacin compatible with breastfeeding.
No dose adjustment required for pregnancy. Standard adult dosing (500 mg on day 1, then 250 mg daily for 4 days) is appropriate. Note: Pregnancy may increase volume of distribution, but pharmacokinetic studies suggest no significant decrease in AUC; no need for dose increase.
Pharmacokinetic changes during pregnancy (e.g., increased volume of distribution, increased renal clearance) may require dose adjustments, but specific guidelines are not established. Generally, standard dosing based on actual body weight and renal function is used. Therapeutic drug monitoring is recommended, especially in third trimester or with concurrent renal impairment. Dose adjustments should be based on serum levels to maintain therapeutic efficacy while minimizing toxicity. No dose reduction is universally recommended; individualize based on renal function and clinical response.
Monitor for QTc prolongation especially in patients with preexisting cardiac conditions or those on other QT-prolonging drugs. Azithromycin has a long half-life (68 hours) allowing for shorter treatment courses. Use with caution in hepatic impairment; consider alternative in severe liver disease. Not recommended for pneumonia in patients with bacteremia due to increased mortality risk. Administer on an empty stomach or with food if GI upset occurs; however, absorption is unaffected by food.
Monitor peak (20-30 mcg/m L) and trough (1-8 mcg/m L) serum levels; adjust dose based on renal function. Avoid concurrent use with other ototoxic/nephrotoxic drugs. Use extended-interval dosing (e.g., 15-20 mg/kg IV once daily) when possible. Assess for vestibular toxicity (ataxia, vertigo) and cochlear toxicity (tinnitus, high-frequency hearing loss).
Take exactly as prescribed; do not skip doses or stop early even if you feel better.,Do not take antacids containing aluminum or magnesium within 2 hours before or after this medication.,Report any signs of liver problems (nausea, vomiting, dark urine, jaundice) or severe diarrhea (watery or bloody) immediately.,Azithromycin may cause dizziness; avoid driving or operating machinery until you know how it affects you.,Inform your doctor if you have a history of QT prolongation, heart rhythm problems, or electrolyte imbalances.,Store at room temperature away from moisture and heat; discard any unused liquid after 10 days.
Report any hearing loss, ringing in ears, dizziness, or unsteadiness immediately.,Drink plenty of fluids to help prevent kidney damage.,Avoid taking other aminoglycosides or strong diuretics unless prescribed.,Inform your doctor if you have kidney disease, myasthenia gravis, or are pregnant.
"Azithromycin, a macrolide antibiotic, is known to prolong the QT interval by blocking cardiac potassium channels (specifically IKr), which can lead to torsades de pointes. Mifepristone also poses a risk of QT prolongation, likely via similar mechanisms. Coadministration may result in additive QTc prolongation, increasing the risk of life-threatening ventricular arrhythmias, especially in patients with preexisting cardiac conditions or electrolyte disturbances."
"Lumiracoxib is a selective COX-2 inhibitor primarily metabolized by CYP2C9 and to a lesser extent by CYP3A4. Azithromycin, a macrolide antibiotic, is a known inhibitor of CYP3A4. Concomitant use may decrease the metabolism of azithromycin, leading to increased plasma concentrations and potential toxicity, such as QT prolongation and hepatotoxicity. Elevated azithromycin levels can also enhance its antibacterial effects but raise safety concerns."
"Azithromycin, a macrolide antibiotic, inhibits the cardiac potassium channel encoded by hERG (human Ether-à-go-go-Related Gene), leading to prolonged cardiac repolarization and increased risk of QTc interval prolongation. Arformoterol, a long-acting beta-2 agonist, can also prolong the QTc interval via beta-adrenergic receptor-mediated effects on cardiac ion channels. Concurrent use may result in additive QTc prolongation, predisposing patients to potentially fatal ventricular arrhythmias such as torsades de pointes."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about AZITHROMYCIN vs AMIKIN, answered by our medical review team.
AZITHROMYCIN is a Macrolide Antibiotic that works by Binds to the 50S ribosomal subunit of susceptible bacteria, inhibiting m RNA translation and thus protein synthesis. Exhibits concentration-dependent bactericidal activity.. AMIKIN is a Aminoglycoside Antibiotic that works by Aminoglycoside antibiotic that binds to the 30S ribosomal subunit, causing misreading of m RNA and inhibition of protein synthesis.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between AZITHROMYCIN and AMIKIN depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of AZITHROMYCIN is: 500 mg orally once daily for 3 days, or 500 mg IV once daily for at least 2 days followed by 500 mg orally to complete 7-10 days of therapy for community-acquired pneumonia. For other indications, typical adult dose is 500 mg orally on day 1 then 250 mg orally once daily on days 2-5.. The standard adult dose of AMIKIN is: 15 mg/kg/day IV or IM divided every 8 to 12 hours; usual adult dose: 15 mg/kg/day. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between AZITHROMYCIN and AMIKIN in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. AZITHROMYCIN is classified as Category A/B. FDA Category B. No evidence of teratogenicity in animal studies; limited human data show no increased risk of major malformations. First trimester: No significant association with . AMIKIN is classified as Category C. Amikacin is an aminoglycoside antibiotic. There are no adequate and well-controlled studies in pregnant women. Animal studies have shown evidence of fetal harm (e.g., nephrotoxicit. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.