Zithromax 250mg Tablets
It is used to treat or prevent bacterial infections.
Drug Class
Antibiotic
Pharmacologic Class
Macrolide Antibiotic
Pregnancy Category
Category B
FDA Approved
Nov 1991
DEA Schedule
Not Controlled
Overview
What is this medicine?
Azithromycin is an antibiotic used to treat various bacterial infections, such as bronchitis, pneumonia, ear infections, and certain sexually transmitted infections. It works by stopping the growth of bacteria.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely. You can take this medication with or without food. However, do not take antacids containing magnesium or aluminum at the same time as your medication. If you have any questions, consult with your doctor or pharmacist.
It's essential to continue taking your medication as directed by your doctor or healthcare provider, even if you start feeling better. This will help ensure that you receive the full benefits of the treatment.
Storing and Disposing of Your Medication
To maintain the quality and safety of your medication, store it at room temperature in a dry place, away from the bathroom. Keep all medications in a secure location, out of the reach of children and pets. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless instructed to do so by your pharmacist. Instead, check with your pharmacist for guidance on the best disposal method or participate in a drug take-back program in your area, if available.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided with your prescription and follow the instructions closely. You can take this medication with or without food. However, do not take antacids containing magnesium or aluminum at the same time as your medication. If you have any questions, consult with your doctor or pharmacist.
It's essential to continue taking your medication as directed by your doctor or healthcare provider, even if you start feeling better. This will help ensure that you receive the full benefits of the treatment.
Storing and Disposing of Your Medication
To maintain the quality and safety of your medication, store it at room temperature in a dry place, away from the bathroom. Keep all medications in a secure location, out of the reach of children and pets. When disposing of unused or expired medications, do not flush them down the toilet or pour them down the drain unless instructed to do so by your pharmacist. Instead, check with your pharmacist for guidance on the best disposal method or participate in a drug take-back program in your area, if available.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
Lifestyle & Tips
- Take the medication exactly as prescribed by your doctor. Do not skip doses or stop taking it early, even if you feel better, as this can lead to antibiotic resistance.
- For Zithromax tablets, take on an empty stomach (at least 1 hour before or 2 hours after a meal) for best absorption. If stomach upset occurs, you may take it with food, but absorption may be reduced.
- Avoid antacids containing aluminum or magnesium within 2 hours of taking azithromycin, as they can decrease its absorption.
- Avoid excessive sun exposure or use sunscreen and wear protective clothing, as azithromycin can increase sensitivity to sunlight.
- Limit alcohol consumption, as it may worsen gastrointestinal side effects.
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
Generic Alternatives:
Dosing & Administration
Adult Dosing
Standard Dose:
Varies by indication. For respiratory tract infections (e.g., community-acquired pneumonia, pharyngitis/tonsillitis): 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5. For uncomplicated Chlamydia trachomatis: 1 gram as a single oral dose.
Dose Range:
250 - 1000 mg
Condition-Specific Dosing:
Community-acquired pneumonia:
500 mg Day 1, then 250 mg Days 2-5
Pharyngitis/Tonsillitis (streptococcal):
500 mg Day 1, then 250 mg Days 2-5
Uncomplicated Chlamydia trachomatis:
1000 mg single dose
Acute bacterial exacerbations of chronic bronchitis:
500 mg Day 1, then 250 mg Days 2-5 OR 500 mg once daily for 3 days
Acute bacterial sinusitis:
500 mg once daily for 3 days
Pediatric Dosing
Neonatal:
Not established for routine use; use only if no alternative and benefits outweigh risks (e.g., pertussis exposure).
Infant:
Acute otitis media: 10 mg/kg (max 500 mg) on Day 1, then 5 mg/kg (max 250 mg) on Days 2-5 OR 10 mg/kg once daily for 3 days. Pharyngitis/Tonsillitis: 12 mg/kg (max 500 mg) once daily for 5 days.
Child:
Acute otitis media: 10 mg/kg (max 500 mg) on Day 1, then 5 mg/kg (max 250 mg) on Days 2-5 OR 10 mg/kg once daily for 3 days. Pharyngitis/Tonsillitis: 12 mg/kg (max 500 mg) once daily for 5 days. Community-acquired pneumonia: 10 mg/kg (max 500 mg) on Day 1, then 5 mg/kg (max 250 mg) on Days 2-5.
Adolescent:
Dosing generally follows adult recommendations for weight >45 kg.
Dose Adjustments
Renal Impairment:
Mild:
No dosage adjustment needed (CrCl >10 mL/min).
Moderate:
No dosage adjustment needed (CrCl >10 mL/min).
Severe:
No dosage adjustment needed (CrCl <10 mL/min), but caution is advised due to limited data.
Dialysis:
Not significantly removed by hemodialysis or peritoneal dialysis. No supplemental dose needed.
Hepatic Impairment:
Mild:
No dosage adjustment needed.
Moderate:
No dosage adjustment needed.
Severe:
Use with caution; azithromycin is primarily eliminated by the liver. Monitor for signs of hepatic dysfunction.
Pharmacology
Mechanism of Action
Azithromycin inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit, thereby blocking the translocation of peptides. This action is typically bacteriostatic, but can be bactericidal at high concentrations against susceptible organisms.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 37% (oral tablet)
Tmax:
2-3 hours
FoodEffect:
Food decreases the absorption of azithromycin immediate-release tablets (Zithromax). It should be taken on an empty stomach (at least 1 hour before or 2 hours after a meal) for optimal absorption, though food may reduce GI upset.
Distribution:
Vd:
Extremely large (31.1 L/kg), indicating extensive tissue distribution and high intracellular concentrations.
ProteinBinding:
Variable, 7% to 51% (concentration-dependent)
CnssPenetration:
Limited (low concentrations in CSF in non-inflamed meninges)
Elimination:
HalfLife:
68 hours (terminal elimination half-life)
Clearance:
Not readily quantifiable due to extensive tissue distribution and slow release from tissues.
ExcretionRoute:
Primarily biliary excretion of unchanged drug; a small amount is excreted renally.
Unchanged:
Approximately 6% of an oral dose is excreted unchanged in urine.
Pharmacodynamics
OnsetOfAction:
Rapid (within hours for antibacterial effect)
PeakEffect:
Achieved at Tmax (2-3 hours in plasma), but tissue concentrations peak later and are sustained.
DurationOfAction:
Prolonged due to long half-life and extensive tissue distribution, allowing for short courses of therapy (e.g., 5-day or 3-day regimens).
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 medical attention immediately:
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 eyesight
Diarrhea, especially if it is severe, bloody, or accompanied by stomach pain or cramps (note: diarrhea is common with antibiotics, but rare cases of C. diff-associated diarrhea, or CDAD, can occur, which may lead to life-threatening bowel problems)
Signs of liver problems, such as:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Severe skin reactions, including:
+ Stevens-Johnson syndrome (SJS)
+ Toxic epidermal necrolysis (TEN)
+ Other serious reactions, which may affect body organs and can be life-threatening
+ Signs of severe skin reactions 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
Most people experience no side effects or only mild side effects while taking this medication. However, if you notice any of the following side effects, contact your doctor or seek medical attention if they bother you or do not go away:
Headache
Diarrhea
Stomach pain
Upset stomach
* Vomiting
Reporting Side Effects
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, 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 medical attention immediately:
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 eyesight
Diarrhea, especially if it is severe, bloody, or accompanied by stomach pain or cramps (note: diarrhea is common with antibiotics, but rare cases of C. diff-associated diarrhea, or CDAD, can occur, which may lead to life-threatening bowel problems)
Signs of liver problems, such as:
+ Dark urine
+ Tiredness
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Severe skin reactions, including:
+ Stevens-Johnson syndrome (SJS)
+ Toxic epidermal necrolysis (TEN)
+ Other serious reactions, which may affect body organs and can be life-threatening
+ Signs of severe skin reactions 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
Most people experience no side effects or only mild side effects while taking this medication. However, if you notice any of the following side effects, contact your doctor or seek medical attention if they bother you or do not go away:
Headache
Diarrhea
Stomach pain
Upset stomach
* Vomiting
Reporting Side Effects
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, 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:
- Signs of an allergic reaction: rash, hives, itching, swelling of the face/lips/tongue/throat, severe dizziness, trouble breathing.
- Severe or watery diarrhea that does not stop, especially if it contains blood or mucus (may be a sign of C. difficile infection).
- Yellowing of the skin or eyes (jaundice), dark urine, pale stools, unusual tiredness, or abdominal pain (signs of liver problems).
- Fast, pounding, or irregular heartbeat, dizziness, or fainting (signs of a serious heart rhythm problem).
- Severe skin reactions (e.g., Stevens-Johnson syndrome, toxic epidermal necrolysis) characterized by fever, sore throat, body aches, rash with blistering and peeling skin.
- New or worsening muscle pain or weakness (especially if taking a statin).
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 and its symptoms.
If you have previously experienced liver problems or jaundice (yellowing of the skin and eyes) while taking this medication.
Certain heart conditions, such as:
+ Long QTc interval on an electrocardiogram (ECG) or other abnormal heart rhythms
+ Slow heartbeat
+ Low potassium or magnesium levels
+ Heart failure (a weakened 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 consult your doctor or pharmacist if you are unsure.
This list is not exhaustive, and it is crucial to discuss all your medications (prescription, over-the-counter, natural products, and vitamins) and health conditions with your doctor and pharmacist. They will help determine whether it is safe to take this medication with your existing treatments and health status. Never start, stop, or adjust the dosage of any medication without first consulting 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 and its symptoms.
If you have previously experienced liver problems or jaundice (yellowing of the skin and eyes) while taking this medication.
Certain heart conditions, such as:
+ Long QTc interval on an electrocardiogram (ECG) or other abnormal heart rhythms
+ Slow heartbeat
+ Low potassium or magnesium levels
+ Heart failure (a weakened 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 consult your doctor or pharmacist if you are unsure.
This list is not exhaustive, and it is crucial to discuss all your medications (prescription, over-the-counter, natural products, and vitamins) and health conditions with your doctor and pharmacist. They will help determine whether it is safe to take this medication with your existing treatments and health status. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
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 may 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. Additionally, be aware that myasthenia gravis symptoms can occur in people without a prior diagnosis. 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
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
In newborns taking this medication, a severe stomach problem can occur. 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 may 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. Additionally, be aware that myasthenia gravis symptoms can occur in people without a prior diagnosis. 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
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
In newborns taking this medication, a severe stomach problem can occur. 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:
In case of overdose, call your poison control center at 1-800-222-1222. Seek immediate medical attention. Treatment is symptomatic and supportive. Gastric lavage and general supportive measures are indicated.
Drug Interactions
Major Interactions
- Amiodarone
- Disopyramide
- Dofetilide
- Ibutilide
- Procainamide
- Quinidine
- Sotalol
- Pimozide
- Thioridazine
- Cisapride
- Ergotamine
- Dihydroergotamine
Moderate Interactions
- Warfarin (increased INR)
- Digoxin (increased levels)
- Cyclosporine (increased levels)
- Nelfinavir (increased azithromycin levels)
- Antacids (aluminum/magnesium-containing, decreased azithromycin absorption)
- Statins (e.g., simvastatin, lovastatin - increased risk of myopathy/rhabdomyolysis)
Minor Interactions
- Zidovudine (increased zidovudine phosphorylation to active metabolite)
Monitoring
Baseline Monitoring
Liver function tests (LFTs)
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 in patients with known hepatic impairment.
Electrocardiogram (ECG)
Rationale: To assess baseline QT interval in patients with known QT prolongation, risk factors for QT prolongation (e.g., uncorrected hypokalemia/hypomagnesemia, bradycardia, heart failure), or those on other QT-prolonging medications.
Timing: Prior to initiation in at-risk patients.
Routine Monitoring
Signs/symptoms of infection resolution
Frequency: Daily during therapy, then as clinically indicated
Target: Improvement in fever, pain, inflammation
Action Threshold: Lack of improvement or worsening symptoms may indicate treatment failure or resistant organism.
Gastrointestinal symptoms (nausea, diarrhea, abdominal pain)
Frequency: Daily during therapy
Target: Tolerable levels
Action Threshold: Severe or persistent diarrhea (especially bloody) may indicate C. difficile infection; severe abdominal pain may indicate pancreatitis.
Cardiac rhythm (for at-risk patients)
Frequency: As clinically indicated, especially if new symptoms of arrhythmia occur
Target: Normal sinus rhythm, no significant QT prolongation
Action Threshold: Palpitations, syncope, or new ECG changes (e.g., prolonged QT, Torsades de Pointes) require immediate evaluation.
INR (if on warfarin)
Frequency: More frequently (e.g., 2-3 times per week) during and immediately after azithromycin therapy
Target: Therapeutic range for indication
Action Threshold: INR outside target range requires warfarin dose adjustment.
Symptom Monitoring
- Rash or allergic reaction (e.g., itching, hives, swelling, difficulty breathing)
- Severe or persistent diarrhea (especially if bloody or watery)
- Yellowing of skin or eyes (jaundice), dark urine, unusual fatigue (signs of liver problems)
- Palpitations, dizziness, fainting (signs of heart rhythm problems)
- Muscle pain or weakness (if on statins)
- Hearing changes (rare, usually reversible)
Special Patient Groups
Pregnancy
Azithromycin is generally considered acceptable for use during pregnancy when indicated, particularly for specific infections like Chlamydia or Mycoplasma pneumonia. It is classified as Pregnancy Category B.
Trimester-Specific Risks:
First Trimester:
No evidence of increased risk of major birth defects based on human data.
Second Trimester:
No evidence of increased risk of major birth defects based on human data.
Third Trimester:
No evidence of increased risk of major birth defects or adverse outcomes. Used for treatment of infections in late pregnancy.
Lactation
Azithromycin is excreted into breast milk in small amounts. It is generally considered compatible with breastfeeding, but monitor the infant for potential adverse effects.
Infant Risk:
L2 - Safer. Low risk of adverse effects in breastfed infants. Potential for altered bowel flora (diarrhea, candidiasis), but serious adverse effects are rare. Consider infant age (older infants may tolerate better) and dose.
Pediatric Use
Widely used and generally well-tolerated in pediatric patients for appropriate indications (e.g., otitis media, pharyngitis, CAP). Dosing is weight-based. Safety and efficacy in infants younger than 6 months for acute otitis media and community-acquired pneumonia have not been established.
Geriatric Use
No dosage adjustment is specifically required based on age. However, elderly patients may be more susceptible to QT prolongation and should be monitored for this risk, especially if they have underlying cardiac conditions or are on other QT-prolonging medications.
Clinical Information
Clinical Pearls
- Azithromycin's long half-life allows for shorter treatment courses (e.g., 3-day or 5-day regimens) and once-daily dosing, which can improve patient adherence.
- It is effective against atypical pathogens (e.g., Mycoplasma, Chlamydia, Legionella), making it a common choice for community-acquired pneumonia.
- Food significantly decreases the absorption of immediate-release azithromycin tablets; advise patients to take it on an empty stomach for optimal efficacy, though taking with food may reduce GI upset.
- Counsel patients on the importance of completing the full course of therapy to prevent antibiotic resistance.
- Be aware of the potential for QT prolongation, especially in patients with pre-existing cardiac conditions, electrolyte imbalances, or those taking other QT-prolonging drugs.
- Warn patients about the risk of C. difficile-associated diarrhea, which can occur even weeks after therapy completion.
Alternative Therapies
- Clarithromycin (another macrolide)
- Erythromycin (another macrolide)
- Doxycycline (tetracycline)
- Levofloxacin (fluoroquinolone)
- Moxifloxacin (fluoroquinolone)
- Amoxicillin (penicillin)
- Amoxicillin/clavulanate (penicillin + beta-lactamase inhibitor)
- Cephalexin (cephalosporin)
- Cefdinir (cephalosporin)
Cost & Coverage
Average Cost:
$10 - $50 per 6 tablets (250mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (Generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it's a good idea to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.