Zithromax 500mg Sdv Inj, 1 Vial
It is used to treat or prevent bacterial infections.
Drug Class
Macrolide Antibiotic
Pharmacologic Class
Macrolide; Protein Synthesis Inhibitor
Pregnancy Category
Category B
FDA Approved
Sep 1995
DEA Schedule
Not Controlled
Overview
What is this medicine?
Azithromycin is an antibiotic that fights bacteria. It is given by injection into a vein to treat certain serious bacterial infections, like pneumonia or pelvic inflammatory disease. It works by stopping the growth of bacteria.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. It is essential to follow the instructions carefully. This medication is administered as an infusion into a vein over a specified period.
Storing and Disposing of Your Medication
If you need to store this medication at home, consult with your doctor, nurse, or pharmacist to determine the proper storage procedure.
Missing a Dose
If you miss a dose, contact your doctor to receive guidance on the next steps to take.
To use this medication correctly, follow your doctor's instructions and read all the information provided. It is essential to follow the instructions carefully. This medication is administered as an infusion into a vein over a specified period.
Storing and Disposing of Your Medication
If you need to store this medication at home, consult with your doctor, nurse, or pharmacist to determine the proper storage procedure.
Missing a Dose
If you miss a dose, contact your doctor to receive guidance on the next steps to take.
Lifestyle & Tips
- Complete the full course of treatment, even if you start feeling better, to prevent the infection from returning and to reduce the risk of antibiotic resistance.
- Report any severe side effects, especially severe diarrhea, rash, or heart palpitations, to your doctor immediately.
- Avoid alcohol if it causes stomach upset, though there is no direct interaction.
Available Forms & Alternatives
Available Strengths:
- Zithromax 200mg Sus 15ml(purple Bx)
- Zithromax 100mg Susp 15ml(green Bx)
- Zithromax 200mg Sus 22.5ml(white Bx
- Zithromax 1gm Powder Packet
- Zithromax 200mg Sus 30ml(yellow Bx)
- Zithromax 600mg Tabs
- Zithromax 250mg Tabs (z-Pak)
- Zithromax 500mg Tab Tri-Pak
- Zithromax 500mg Tablets
- Zithromax 500mg Sdv Inj, 1 Vial
- Zithromax 250mg 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 7-10 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 (CAP):
500 mg IV once daily for at least 2 days, then switch to oral.
Pelvic Inflammatory Disease (PID):
500 mg IV once daily for 1-2 days, then switch to oral.
Pediatric Dosing
Neonatal:
Not established for IV use in neonates.
Infant:
Not established for IV use in infants.
Child:
Not established for IV use in children under 16 years for CAP or PID.
Adolescent:
Community-Acquired Pneumonia (CAP) (âĨ16 years): 500 mg IV as a single daily dose for at least 2 days, followed by oral azithromycin 500 mg daily to complete a 7-10 day course. Pelvic Inflammatory Disease (PID) (âĨ16 years): 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 Adjustments
Renal Impairment:
Mild:
No dosage adjustment necessary.
Moderate:
No dosage adjustment necessary.
Severe:
No dosage adjustment necessary for CrCl > 10 mL/min. Caution advised for CrCl < 10 mL/min due to limited data.
Dialysis:
Not available (limited data, generally no adjustment needed for CrCl > 10 mL/min).
Hepatic Impairment:
Mild:
No dosage adjustment necessary.
Moderate:
No dosage adjustment necessary.
Severe:
Use with caution; azithromycin is primarily eliminated by the liver. Avoid use in patients with severe hepatic impairment.
Pharmacology
Mechanism of Action
Azithromycin binds to the 50S ribosomal subunit of susceptible microorganisms, thereby inhibiting bacterial protein synthesis. It is generally considered bacteriostatic, but can be bactericidal at high concentrations against certain organisms.
Pharmacokinetics
Absorption:
Bioavailability:
Not applicable for IV (100% for IV administration). Oral bioavailability is approximately 37%.
Tmax:
Not applicable for IV (peak plasma concentrations are achieved rapidly after infusion).
FoodEffect:
Not applicable for IV.
Distribution:
Vd:
Extremely large (31.1 L/kg), indicating extensive tissue distribution.
ProteinBinding:
Variable, 7% to 51% (decreases with increasing plasma concentrations).
CnssPenetration:
Limited (low concentrations in CSF in non-inflamed meninges).
Elimination:
HalfLife:
Terminal elimination half-life is 2-4 days (due to extensive tissue distribution and slow release from tissues).
Clearance:
Not available (primarily eliminated via biliary excretion).
ExcretionRoute:
Primarily biliary excretion of unchanged drug. A small amount is excreted renally.
Unchanged:
Approximately 6% of an IV dose is excreted unchanged in urine.
Pharmacodynamics
OnsetOfAction:
Rapid (achieves therapeutic concentrations in tissues within hours of administration).
PeakEffect:
Not available (related to tissue concentrations rather than plasma peak).
DurationOfAction:
Prolonged (due to long tissue half-life, allowing for once-daily dosing and shorter treatment courses).
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ 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
+ Swelling of the mouth, face, lips, tongue, or throat
Chest pain or pressure
Fast heartbeat or abnormal heartbeat
Dizziness or fainting
Changes in hearing
Fever
Changes in vision
Diarrhea, especially if it is severe, bloody, or watery (note: diarrhea is a common side effect of antibiotics, but in rare cases, it can lead to a life-threatening condition called C. diff-associated diarrhea, or CDAD)
Stomach pain, cramps, or very loose, watery, or bloody stools (if you experience any of these symptoms, contact your doctor before treating diarrhea)
Signs of liver problems, such as:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes (liver problems can be life-threatening, so seek medical help immediately if you notice any of these symptoms)
Severe skin reactions, including:
+ Stevens-Johnson syndrome (SJS)
+ Toxic epidermal necrolysis (TEN)
+ Other serious reactions that can affect the skin and other organs
+ Symptoms may include:
- Red, swollen, blistered, or peeling skin
- Red or irritated eyes
- Sores in the mouth, throat, nose, eyes, genitals, or skin
- Fever
- Chills
- Body aches
- Shortness of breath
- Swollen glands
Other Possible Side Effects
Like all medications, this drug can cause side effects, although not everyone will experience them. If you notice any of the following side effects, contact your doctor or seek medical help if they bother you or do not go away:
Headache
Diarrhea
Stomach pain
Upset stomach
Vomiting
* Pain at the injection site
Reporting Side Effects
If you have questions about side effects or experience any symptoms that concern you, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ 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
+ Swelling of the mouth, face, lips, tongue, or throat
Chest pain or pressure
Fast heartbeat or abnormal heartbeat
Dizziness or fainting
Changes in hearing
Fever
Changes in vision
Diarrhea, especially if it is severe, bloody, or watery (note: diarrhea is a common side effect of antibiotics, but in rare cases, it can lead to a life-threatening condition called C. diff-associated diarrhea, or CDAD)
Stomach pain, cramps, or very loose, watery, or bloody stools (if you experience any of these symptoms, contact your doctor before treating diarrhea)
Signs of liver problems, such as:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes (liver problems can be life-threatening, so seek medical help immediately if you notice any of these symptoms)
Severe skin reactions, including:
+ Stevens-Johnson syndrome (SJS)
+ Toxic epidermal necrolysis (TEN)
+ Other serious reactions that can affect the skin and other organs
+ Symptoms may include:
- Red, swollen, blistered, or peeling skin
- Red or irritated eyes
- Sores in the mouth, throat, nose, eyes, genitals, or skin
- Fever
- Chills
- Body aches
- Shortness of breath
- Swollen glands
Other Possible Side Effects
Like all medications, this drug can cause side effects, although not everyone will experience them. If you notice any of the following side effects, contact your doctor or seek medical help if they bother you or do not go away:
Headache
Diarrhea
Stomach pain
Upset stomach
Vomiting
* Pain at the injection site
Reporting Side Effects
If you have questions about side effects or experience any symptoms that concern you, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe allergic reaction (hives, difficulty breathing, swelling of your face, lips, tongue, or throat)
- Severe stomach pain, watery or bloody diarrhea (even if it occurs months after your last dose)
- Signs of liver problems (nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes))
- Heart rhythm problems (fast or pounding heartbeats, fluttering in your chest, shortness of breath, sudden dizziness)
- Severe skin reaction (fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads and causes blistering and peeling)
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following conditions to ensure safe treatment:
Any allergies you have, including allergies to this medication, its components, or other substances. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have previously experienced liver problems or jaundice (yellowing of the skin or eyes) while taking this medication.
Certain health conditions, such as:
+ Abnormal heart rhythms, including a prolonged QTc interval on an electrocardiogram (ECG) or other irregular heartbeats.
+ Slow heartbeat or low levels of potassium or magnesium in your blood.
+ Heart failure, also known as a weak heart.
+ A history of torsades de pointes, a specific type of abnormal heartbeat.
If you are taking any medications that can cause abnormal heart rhythms, particularly those that prolong the QT interval. There are many medications that can have this effect, so it is crucial to consult with your doctor or pharmacist if you are unsure.
To ensure your safety, it is vital to provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter medications you are currently taking.
Any natural products, vitamins, or supplements you are using.
* Your complete medical history, including any health problems you have or have had in the past.
Do not start, stop, or change the dosage of any medication without first consulting your doctor to confirm that it is safe to do so in conjunction with this medication.
It is essential to inform your doctor about the following conditions to ensure safe treatment:
Any allergies you have, including allergies to this medication, its components, or other substances. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have previously experienced liver problems or jaundice (yellowing of the skin or eyes) while taking this medication.
Certain health conditions, such as:
+ Abnormal heart rhythms, including a prolonged QTc interval on an electrocardiogram (ECG) or other irregular heartbeats.
+ Slow heartbeat or low levels of potassium or magnesium in your blood.
+ Heart failure, also known as a weak heart.
+ A history of torsades de pointes, a specific type of abnormal heartbeat.
If you are taking any medications that can cause abnormal heart rhythms, particularly those that prolong the QT interval. There are many medications that can have this effect, so it is crucial to consult with your doctor or pharmacist if you are unsure.
To ensure your safety, it is vital to provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter medications you are currently taking.
Any natural products, vitamins, or supplements you are using.
* Your complete medical history, including any health problems you have or have had in the past.
Do not start, stop, or change the dosage of any medication without first consulting your doctor to confirm that it is safe to do so in conjunction with this medication.
Precautions & Cautions
Important Warnings and Cautions for Patients Taking This Medication
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Adhere to the prescribed duration of treatment, as prolonged use may increase the risk of a second infection.
Severe Heart Rhythm Changes
This medication can cause severe heart rhythm changes, including a prolonged QT interval, which can be life-threatening or fatal. If you have any questions or concerns, consult your doctor.
Myasthenia Gravis
If you have myasthenia gravis, discuss your treatment with your doctor. Monitor your symptoms closely, and contact your doctor if they worsen. Even if you do not have myasthenia gravis, be aware of the potential for muscle weakness and other symptoms. Seek immediate medical attention if you experience new or worsening muscle weakness, difficulty chewing or swallowing, breathing problems, droopy eyelids, or changes in vision, such as blurred vision or double vision.
Special Considerations for Older Adults
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.
Pregnancy and Breastfeeding
If you are pregnant, plan to become pregnant, or are breastfeeding, consult your doctor to discuss the potential benefits and risks to you and your baby.
Newborns
Newborns taking this medication are at risk of developing a severe stomach problem. If your child vomits or becomes irritable during feeding, contact your doctor immediately.
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Adhere to the prescribed duration of treatment, as prolonged use may increase the risk of a second infection.
Severe Heart Rhythm Changes
This medication can cause severe heart rhythm changes, including a prolonged QT interval, which can be life-threatening or fatal. If you have any questions or concerns, consult your doctor.
Myasthenia Gravis
If you have myasthenia gravis, discuss your treatment with your doctor. Monitor your symptoms closely, and contact your doctor if they worsen. Even if you do not have myasthenia gravis, be aware of the potential for muscle weakness and other symptoms. Seek immediate medical attention if you experience new or worsening muscle weakness, difficulty chewing or swallowing, breathing problems, droopy eyelids, or changes in vision, such as blurred vision or double vision.
Special Considerations for Older Adults
If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects.
Pregnancy and Breastfeeding
If you are pregnant, plan to become pregnant, or are breastfeeding, consult your doctor to discuss the potential benefits and risks to you and your baby.
Newborns
Newborns taking this medication are at risk of developing a severe stomach problem. If your child vomits or becomes irritable during feeding, contact your doctor immediately.
Overdose Information
Overdose Symptoms:
- Severe nausea
- Vomiting
- Diarrhea
- Reversible hearing loss
What to Do:
Call 1-800-222-1222 (Poison Control). Treatment is symptomatic and supportive. Gastric lavage and general supportive measures are indicated as required.
Drug Interactions
Major Interactions
- QT-prolonging drugs (e.g., antiarrhythmics like amiodarone, quinidine; antipsychotics like pimozide; tricyclic antidepressants; fluoroquinolones)
- Nelfinavir (increased azithromycin concentrations)
- Warfarin (increased anticoagulant effect, monitor INR)
Moderate Interactions
- Digoxin (increased digoxin levels, monitor levels)
- Cyclosporine (increased cyclosporine levels, monitor levels)
- Antacids containing aluminum or magnesium (decreased oral azithromycin absorption, not relevant for IV)
- Ergot derivatives (theoretical risk of ergotism, avoid concomitant use)
Monitoring
Baseline Monitoring
Liver function tests (ALT, AST, bilirubin)
Rationale: To assess baseline hepatic function, especially in patients with pre-existing liver disease, as azithromycin is primarily eliminated by the liver.
Timing: Prior to initiation of therapy.
Renal function (CrCl)
Rationale: To assess baseline renal function, though dose adjustment is generally not needed for mild-moderate impairment.
Timing: Prior to initiation of therapy.
Electrolytes (Potassium, Magnesium)
Rationale: To identify patients at increased risk for QT prolongation.
Timing: Prior to initiation of therapy in at-risk patients.
Electrocardiogram (ECG)
Rationale: To assess baseline QT interval in patients with known cardiac conditions, electrolyte disturbances, or those on other QT-prolonging drugs.
Timing: Prior to initiation of therapy in at-risk patients.
Routine Monitoring
Clinical response to therapy
Frequency: Daily
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 (ALT, AST, bilirubin)
Frequency: Periodically, especially with prolonged therapy or in patients with pre-existing hepatic impairment.
Target: Within normal limits or stable from baseline.
Action Threshold: Significant elevation (e.g., >3x ULN) or signs of liver injury warrant discontinuation.
INR (if on warfarin)
Frequency: More frequently during and after azithromycin therapy.
Target: Therapeutic range for indication.
Action Threshold: INR outside target range requires warfarin dose adjustment.
Digoxin levels (if on digoxin)
Frequency: Monitor closely during and after azithromycin therapy.
Target: Therapeutic range for indication.
Action Threshold: Elevated digoxin levels require dose adjustment.
ECG (QTc interval)
Frequency: Consider for patients at high risk of QT prolongation (e.g., pre-existing cardiac disease, electrolyte abnormalities, concomitant QT-prolonging drugs).
Target: < 450 ms (men), < 470 ms (women)
Action Threshold: Significant QTc prolongation (>500 ms or increase of >60 ms from baseline) warrants discontinuation or alternative therapy.
Symptom Monitoring
- Signs of allergic reaction (rash, itching, swelling, severe dizziness, trouble breathing)
- Severe or persistent diarrhea (may indicate Clostridioides difficile-associated diarrhea)
- Signs of liver injury (unusual tiredness, yellowing of skin/eyes, dark urine, abdominal pain)
- Symptoms of cardiac arrhythmia (palpitations, dizziness, fainting, chest pain)
- Signs of superinfection (new or worsening symptoms of infection)
Special Patient Groups
Pregnancy
Azithromycin is classified as Pregnancy Category B. Studies in animals have not shown harm to the fetus, but there are no adequate and well-controlled studies in pregnant women. It is generally considered acceptable for use when clearly needed.
Trimester-Specific Risks:
First Trimester:
No increased risk of major birth defects observed in human studies.
Second Trimester:
Generally considered safe, often used for certain infections during this trimester.
Third Trimester:
Generally considered safe, often used for certain infections during this trimester.
Lactation
Azithromycin is excreted into breast milk in small amounts. The American Academy of Pediatrics considers it compatible with breastfeeding. Monitor the infant for potential adverse effects such as diarrhea, vomiting, or rash.
Infant Risk:
Low risk (L3 - Moderately safe).
Pediatric Use
Safety and effectiveness of intravenous azithromycin in pediatric patients under 16 years of age have not been established for the treatment of Community-Acquired Pneumonia or Pelvic Inflammatory Disease. Oral azithromycin is approved for various pediatric indications.
Geriatric Use
No dosage adjustment is necessary for elderly patients. However, elderly patients may be more susceptible to drug-associated QT interval prolongation and should be monitored for cardiac adverse events, especially if they have pre-existing cardiac conditions or are on other QT-prolonging medications.
Clinical Information
Clinical Pearls
- Azithromycin IV is typically used as initial therapy for severe infections, with a rapid switch to oral therapy once the patient's condition improves, due to its excellent tissue penetration and long half-life.
- Infuse azithromycin IV over no less than 60 minutes to minimize local reactions at the infusion site.
- Due to the risk of QT prolongation, use with caution in patients with known QT prolongation, a history of torsades de pointes, uncorrected hypokalemia or hypomagnesemia, clinically significant bradycardia, or those receiving other QT-prolonging drugs.
- Azithromycin has good activity against atypical pathogens (e.g., Mycoplasma pneumoniae, Chlamydophila pneumoniae) which are common causes of CAP.
- Monitor for C. difficile-associated diarrhea, which can occur during or even months after antibiotic therapy.
Alternative Therapies
- Other macrolides (e.g., erythromycin, clarithromycin)
- Beta-lactam antibiotics (e.g., ceftriaxone, ampicillin/sulbactam for CAP; cefoxitin, clindamycin for PID)
- Fluoroquinolones (e.g., levofloxacin, moxifloxacin for CAP or PID)
- Tetracyclines (e.g., doxycycline for PID)
Cost & Coverage
Average Cost:
Varies widely by pharmacy and contract per 500mg vial
Generic Available:
Yes
Insurance Coverage:
Tier 1 or 2 (generic), Tier 3 (brand)
General Drug Facts
If your symptoms or health problems do not improve or worsen over time, it is essential to contact your doctor for further evaluation and guidance.
To ensure safe use, do not share your medication with others, and never take someone else's medication. Store all medications in a secure location, out of reach of children and pets, to prevent accidental ingestion.
Proper disposal of unused or expired medications is crucial. Do not flush medications down the toilet or pour them down the drain unless specifically instructed to do so by a healthcare professional or pharmacist. If you are unsure about the best method for disposing of medications, consult with your pharmacist, who can provide guidance on safe disposal practices. Additionally, you may want to inquire about potential drug take-back programs in your area.
Some medications may come with an additional patient information leaflet. If you have any questions or concerns about your medication, it is recommended that you consult 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 emergency medical attention. Be prepared to provide critical information, including the name of the medication taken, the amount, and the time it was taken, to ensure prompt and effective treatment.
To ensure safe use, do not share your medication with others, and never take someone else's medication. Store all medications in a secure location, out of reach of children and pets, to prevent accidental ingestion.
Proper disposal of unused or expired medications is crucial. Do not flush medications down the toilet or pour them down the drain unless specifically instructed to do so by a healthcare professional or pharmacist. If you are unsure about the best method for disposing of medications, consult with your pharmacist, who can provide guidance on safe disposal practices. Additionally, you may want to inquire about potential drug take-back programs in your area.
Some medications may come with an additional patient information leaflet. If you have any questions or concerns about your medication, it is recommended that you consult 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 emergency medical attention. Be prepared to provide critical information, including the name of the medication taken, the amount, and the time it was taken, to ensure prompt and effective treatment.