Azithromycin 500mg Inj, 1 Vial
It is used to treat or prevent bacterial infections.
Drug Class
Macrolide Antibiotic
Pharmacologic Class
Macrolide; Protein Synthesis Inhibitor
Pregnancy Category
B
FDA Approved
Sep 1995
DEA Schedule
Not Controlled
Overview
What is this medicine?
Azithromycin is an antibiotic medication given through an IV (intravenous) line. It's used to treat certain bacterial infections, like pneumonia or pelvic inflammatory disease, by stopping the growth of bacteria. It's important to complete the full course of treatment as prescribed by your doctor, even if you start feeling better.
How to Use This Medicine
To use this medication correctly, follow your doctor's instructions and carefully read all accompanying information. Take this medication exactly as directed, and adhere to all guidelines provided. This drug is administered via infusion into a vein over a specified period of time.
For storage and disposal, consult with your doctor, nurse, or pharmacist to determine the best approach if you need to keep this medication at home.
If you miss a dose, contact your doctor immediately to receive guidance on the appropriate course of action.
For storage and disposal, consult with your doctor, nurse, or pharmacist to determine the best approach if you need to keep this medication at home.
If you miss a dose, contact your doctor immediately to receive guidance on the appropriate course of action.
Lifestyle & Tips
- Report any unusual or severe side effects to your healthcare provider immediately.
- Do not stop the medication early, even if symptoms improve, unless advised by your doctor.
- Stay hydrated, especially if experiencing diarrhea.
Available Forms & Alternatives
Available Strengths:
- Azithromycin 500mg Inj, 1 Vial
- Azithromycin 1gm Pak Powder
- Azithromycin 600mg Tablets
- Azithromycin 200mg/5ml Susp 15ml
- Azithromycin 200mg/5ml Susp 30ml
- Azithromycin 200mg/5ml Susp 22.5ml
- Azithromycin 100mg/5ml Susp 15ml
- Azithromycin 500mg Sdv Inj, 1 Vial
- Azithromycin 250mg Tablets 6-Pak
- Azithromycin 600mg Tablets
- Azithromycin 500mg Tablets Tri-Pack
- Azithromycin 250mg Tablets
- Azithromycin 500mg Tablets
- Azithromycin 600mg Tablets
Dosing & Administration
Adult Dosing
Standard Dose:
Community-acquired pneumonia (CAP): 500 mg IV as a single daily dose for at least 2 days, followed by oral azithromycin 500 mg daily to complete a 7- to 10-day course. Pelvic inflammatory disease (PID): 500 mg IV as a single daily dose for 1 or 2 days, followed by oral azithromycin 250 mg daily to complete a 7-day course.
Dose Range:
500 - 500 mg
Condition-Specific Dosing:
Community-acquired pneumonia:
500 mg IV daily for 2+ days, then switch to oral to complete 7-10 days.
Pelvic inflammatory disease:
500 mg IV daily for 1-2 days, then switch to oral to complete 7 days.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established for IV use under 6 months.
Child:
Community-acquired pneumonia (âĨ6 months): 10 mg/kg IV on Day 1 (max 500 mg), then 5 mg/kg IV daily on Days 2-5 (max 250 mg/day). Or 10 mg/kg IV once daily for 1-2 days, then switch to oral.
Adolescent:
Same as adult dosing for relevant indications.
Dose Adjustments
Renal Impairment:
Mild:
No dosage adjustment necessary.
Moderate:
No dosage adjustment necessary.
Severe:
Use with caution; data limited. No specific dosage adjustment recommendations.
Dialysis:
Not significantly removed by hemodialysis or peritoneal dialysis. No specific dosage adjustment recommendations.
Hepatic Impairment:
Mild:
No specific dosage adjustment recommendations.
Moderate:
Use with caution; monitor for signs of hepatic dysfunction.
Severe:
Use with caution; monitor for signs of hepatic dysfunction. No specific dosage adjustment recommendations.
Pharmacology
Mechanism of Action
Azithromycin binds to the 50S ribosomal subunit of susceptible microorganisms, thereby inhibiting bacterial protein synthesis. It does not affect nucleic acid synthesis.
Pharmacokinetics
Absorption:
Bioavailability:
100% (for IV administration)
Tmax:
End of infusion
FoodEffect:
Not applicable for IV formulation
Distribution:
Vd:
31.1 L/kg (extensive tissue distribution)
ProteinBinding:
7-51% (concentration-dependent)
CnssPenetration:
Limited
Elimination:
HalfLife:
68 hours (terminal elimination half-life)
Clearance:
Not readily quantifiable due to extensive tissue distribution and biliary excretion.
ExcretionRoute:
Primarily biliary excretion (unchanged drug and metabolites)
Unchanged:
Approximately 6% of the dose is excreted unchanged in urine.
Pharmacodynamics
OnsetOfAction:
Rapid (following IV infusion)
PeakEffect:
End of infusion
DurationOfAction:
Due to high tissue concentrations and long half-life, effects persist for several days after the last dose (post-antibiotic effect).
Safety & Warnings
Side Effects
WHAT ARE SOME SIDE EFFECTS THAT I NEED TO CALL MY DOCTOR ABOUT RIGHT AWAY? WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.Chest pain or pressure, a fast heartbeat, or an abnormal heartbeat.Dizziness or passing out.Change in hearing.Fever.Change in eyesight.Diarrhea is common with antibiotics. Rarely, a severe form called C diff?associated diarrhea (CDAD) may happen. Sometimes, this has led to a deadly bowel problem. CDAD may happen during or a few months after taking antibiotics. Call your doctor right away if you have stomach pain, cramps, or very loose, watery, or bloody stools. Check with your doctor before treating diarrhea.Liver problems have happened with this drug. Rarely, this has been deadly. Call your doctor right away if you have signs of liver problems like dark urine, tiredness, decreased appetite, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.Severe skin reactions may happen with this drug. These include Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and other serious reactions. Sometimes, body organs may also be affected. These reactions can be deadly. Get medical help right away if you have signs like red, swollen, blistered, or peeling skin; red or irritated eyes; sores in your mouth, throat, nose, eyes, genitals, or any areas of skin; fever; chills; body aches; shortness of breath; or swollen glands. WHAT ARE SOME OTHER SIDE EFFECTS OF THIS DRUG? All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:Headache.Diarrhea, stomach pain, upset stomach, or throwing up.Pain where the shot was given.These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.You may report side effects to the FDA at 1-800-332- 1088. You may also report side effects at https:// www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe or watery diarrhea (especially if bloody or prolonged)
- Yellowing of the skin or eyes (jaundice)
- Dark urine or pale stools
- Severe stomach pain
- Unusual bleeding or bruising
- Fast, pounding, or irregular heartbeat
- Dizziness or fainting spells
- Severe skin rash, blistering, or peeling skin
- Swelling of the face, lips, tongue, or throat; difficulty breathing or swallowing (signs of severe allergic reaction)
Before Using This Medicine
WHAT DO I NEED TO TELL MY DOCTOR BEFORE I TAKE THIS DRUG? TELL YOUR DOCTOR: If you are allergic to this drug; any part of this drug; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.If you have turned yellow or had liver side effects with this drug before.If you have any of these health problems: Long QTc on ECG or other heartbeat that is not normal, slow heartbeat, or low potassium or magnesium levels.If you have heart failure (weak heart).If you have ever had a certain type of abnormal heartbeat (torsades de pointes).If you are taking any drugs that can cause a certain type of heartbeat that is not normal (prolonged QT interval). There are many drugs that can do this. Ask your doctor or pharmacist if you are not sure.This is not a list of all drugs or health problems that interact with this drug.Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this drug with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.
Precautions & Cautions
For all patients taking this drug:Tell all of your health care providers that you take this drug. This includes your doctors, nurses, pharmacists, and dentists.Do not use longer than you have been told. A second infection may happen. Severe heart rhythm changes like prolonged QT interval have happened with this drug. Sometimes, these can be life-threatening or deadly. If you have questions, talk with the doctor.If you have myasthenia gravis, talk with your doctor. Call your doctor if your signs get worse. Signs of myasthenia gravis have also happened in people who do not have it. Call your doctor right away if you have new or worse muscle weakness, trouble chewing or swallowing, trouble breathing, droopy eyelids, or change in eyesight like blurred eyesight or seeing double.If you are 65 or older, use this drug with care. You could have more side effects.Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.Newborns:A very bad stomach problem has happened in newborns taking this drug. Call the doctor right away if your child throws up or gets irritable with feeding.
Overdose Information
Overdose Symptoms:
- Severe nausea
- Vomiting
- Diarrhea
- Reversible hearing loss
What to Do:
In case of suspected overdose, seek immediate medical attention or call a poison control center. In the US, call 1-800-222-1222. Management is supportive and symptomatic.
Drug Interactions
Contraindicated Interactions
- Pimozide (risk of QT prolongation)
Major Interactions
- Warfarin (increased INR, bleeding risk)
- Nelfinavir (increased azithromycin levels)
- Ergot derivatives (e.g., ergotamine, dihydroergotamine - risk of ergotism)
- QT-prolonging drugs (e.g., Class IA and III antiarrhythmics, cisapride, terfenadine, some antipsychotics, tricyclic antidepressants, fluoroquinolones - increased risk of Torsades de Pointes)
Moderate Interactions
- Cyclosporine (increased cyclosporine levels)
- Digoxin (increased digoxin levels)
- Atorvastatin (rare reports of rhabdomyolysis, monitor for muscle pain)
- Colchicine (increased colchicine exposure)
Minor Interactions
- Antacids (oral only, not relevant for IV)
Monitoring
Baseline Monitoring
Liver Function Tests (LFTs)
Rationale: To assess baseline hepatic function, especially in patients with pre-existing liver disease.
Timing: Prior to initiation of therapy if hepatic impairment is suspected or known.
Electrocardiogram (ECG)
Rationale: To assess baseline QT interval, especially in patients with known QT prolongation, uncorrected hypokalemia/hypomagnesemia, bradycardia, or concurrent use of other QT-prolonging drugs.
Timing: Prior to initiation of therapy if risk factors for QT prolongation are present.
Routine Monitoring
Clinical response to therapy
Frequency: Daily during acute treatment, then as clinically indicated.
Target: Resolution of signs and symptoms of infection.
Action Threshold: Lack of improvement or worsening symptoms may indicate treatment failure or resistant organism.
Liver Function Tests (LFTs)
Frequency: As clinically indicated, especially with prolonged therapy or signs/symptoms of hepatic dysfunction (e.g., jaundice, dark urine, fatigue).
Target: Within normal limits or stable.
Action Threshold: Significant elevation (e.g., >3x ULN) may warrant discontinuation.
ECG monitoring (QTc interval)
Frequency: Periodically, if risk factors for QT prolongation persist or new risk factors emerge.
Target: QTc < 450 ms (men), < 470 ms (women).
Action Threshold: QTc prolongation > 500 ms or increase of > 60 ms from baseline may warrant discontinuation or closer monitoring.
INR (if on warfarin)
Frequency: More frequently during and after azithromycin therapy.
Target: Individualized therapeutic range.
Action Threshold: INR outside target range requires dose adjustment of warfarin.
Symptom Monitoring
- Signs of allergic reaction (rash, itching, hives, swelling of face/lips/tongue/throat, difficulty breathing)
- Severe or persistent diarrhea (may indicate Clostridioides difficile-associated diarrhea)
- Signs of hepatotoxicity (yellowing of skin/eyes, dark urine, pale stools, severe stomach pain, unusual fatigue)
- Signs of QT prolongation/arrhythmia (palpitations, dizziness, lightheadedness, fainting, shortness of breath)
- Signs of superinfection (new or worsening fever, new infection symptoms)
- Muscle pain or weakness (if on statins)
Special Patient Groups
Pregnancy
Pregnancy Category B. Studies in animals have not shown harm to the fetus. Adequate and well-controlled studies in pregnant women are lacking. Use during pregnancy only if clearly needed and the potential benefits outweigh the potential risks.
Trimester-Specific Risks:
First Trimester:
No evidence of increased risk of congenital anomalies based on available data.
Second Trimester:
Generally considered safe for use if indicated.
Third Trimester:
Generally considered safe for use if indicated.
Lactation
Lactation Risk Category L3 (Moderately Safe). Azithromycin is excreted into breast milk in low concentrations. Potential for infant gastrointestinal upset (diarrhea, vomiting) or alteration of gut flora. Monitor breastfed infant for side effects.
Infant Risk:
Low to moderate risk of adverse effects. Monitor for diarrhea, vomiting, rash, or candidiasis.
Pediatric Use
Safe and effective for certain indications in children 6 months of age and older. Dosing is weight-based. Safety and effectiveness in pediatric patients under 6 months of age have not been established.
Geriatric Use
No specific dosage adjustment is necessary based on age alone. However, elderly patients may be more susceptible to drug-associated QT interval prolongation. Monitor carefully, especially if co-morbidities or concomitant medications increase this risk.
Clinical Information
Clinical Pearls
- Azithromycin IV should be administered as an intravenous infusion over at least 60 minutes to minimize local reactions at the infusion site.
- Do NOT administer azithromycin IV as a bolus or intramuscular injection.
- Patients should be switched to oral azithromycin therapy as soon as clinically appropriate.
- Azithromycin exhibits a long post-antibiotic effect and high tissue penetration, allowing for once-daily dosing and shorter courses of therapy compared to some other antibiotics.
- Caution is advised in patients with pre-existing QT prolongation, uncorrected hypokalemia/hypomagnesemia, clinically significant bradycardia, or those receiving other drugs known to prolong the QT interval, due to the risk of Torsades de Pointes.
- Monitor for signs of C. difficile-associated diarrhea, which can occur even several months after antibiotic discontinuation.
Alternative Therapies
- Other macrolides (e.g., clarithromycin, erythromycin)
- Tetracyclines (e.g., doxycycline)
- Fluoroquinolones (e.g., levofloxacin, moxifloxacin)
- Beta-lactam antibiotics (e.g., ceftriaxone, amoxicillin/clavulanate)
- Depending on the specific infection and susceptibility patterns.
Cost & Coverage
Average Cost:
Varies widely by manufacturer and quantity per 500mg vial
Generic Available:
Yes
Insurance Coverage:
Typically covered as a Tier 1 or Tier 2 medication by most insurance plans for generic formulations.
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe use, never share your medication with others or take someone else's medication. Store all medications in a secure location, out of reach of children and pets, to prevent accidental ingestion. Dispose of unused or expired medications properly; do not flush them down the toilet or pour them down the drain unless instructed to do so by a healthcare professional or pharmacist. If you are unsure about the correct disposal method, consult your pharmacist, as they can provide guidance on available drug take-back programs in your area. Additionally, some medications may come with a separate patient information leaflet, which can be obtained from your pharmacist. If you have any questions or concerns about your medication, it is crucial to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately contact your local poison control center or seek medical attention. Be prepared to provide information about the medication taken, the amount, and the time it occurred to ensure timely and effective treatment.