Z-Pak (Azithromycin) Patient Instructions
Take 500 mg (two 250 mg tablets) on Day 1, then take 250 mg (one tablet) once daily on Days 2 through 5, for a total of 5 days of treatment. 1, 2
How to Take Your Medication
- Take azithromycin once daily at approximately the same time each day 3
- You can take it with or without food 3
- Do NOT take aluminum- or magnesium-containing antacids (like Maalox, Mylanta, or Tums) at the same time as azithromycin—these reduce absorption by up to 50%. If you need an antacid, separate it from your azithromycin dose by at least 2 hours 1, 3
Complete the Full Course
- Take all 5 days of medication even if you feel better after 2-3 days 3
- Stopping early decreases effectiveness and increases the risk that bacteria will become resistant to antibiotics in the future 3
- The medication continues working in your tissues for several days after you finish the course due to its long-lasting effects 4, 5
Common Side Effects (Usually Mild)
The most common side effects are gastrointestinal and generally mild to moderate 6, 2:
- Diarrhea
- Nausea or vomiting
- Abdominal discomfort or pain
- Headache
- Dizziness
These side effects are less frequent and better tolerated than with older antibiotics like erythromycin 7, 8
When to Call Your Doctor Immediately
Stop taking azithromycin and contact your physician right away if you develop: 3
- Signs of an allergic reaction (rash, hives, difficulty breathing, swelling of face/lips/tongue)
- Severe or bloody diarrhea, even if it occurs weeks after finishing the medication
- Severe abdominal pain
- Yellowing of skin or eyes
- Irregular heartbeat or chest pain
Important Drug Interactions
- If you take warfarin (Coumadin) or other blood thinners, your doctor may need to monitor your blood clotting times more closely 3
- Inform your doctor of all medications you're taking, especially heart rhythm medications 3
Special Considerations
- Pregnancy: Azithromycin is FDA Pregnancy Category B and considered safe during pregnancy 6, 2
- Liver or kidney disease: Inform your doctor if you have impaired liver or kidney function, as caution is needed 3
- Myasthenia gravis: Tell your doctor if you have this condition, as azithromycin can worsen symptoms 3
Storage
- Store at room temperature away from moisture and heat
- Keep out of reach of children