What is Zithromax Injection (azithromycin)?
Zithromax is a brand name for azithromycin which belongs to a class called macrolide antibiotics. It is used to prevent and treat certain bacterial infections, including ear, throat, lung, tonsil, sinus and reproductive organ infections.
- It is not effective on viral infections, such as colds and flu.
- Since the liver is the main organ that eliminates Zithromax from the body, some patients with liver problems may need to use another medication while others may still be able to use it with close monitoring.
- As with all antibiotics, to avoid the development of drug-resistant bacteria, Zithromax should only be used when tests confirm or if your healthcare team strongly suspects that the infection is caused by bacteria susceptible to Zithromax.
- There is only limited research on the relationship between breastfeeding and risk to infants. The results show that a small amount of Zithromax is present in breastmilk, but there were no adverse effects to infants from that amount. The research did not include infants younger than six months.
- There is not enough research on the effect of Zithromax on pregnant women and their unborn children. Your doctor should weigh the risks and benefits when determining whether Zithromax is the right medicine for you.
- There is not enough research on the effects on children under the age of 16.
- Studies have shown that elderly patients are more prone to developing Torsades de Pointes (TdP) while taking Zithromax. TdP is an abnormal heart rhythm that can be fatal if left untreated.
How does Zithromax Injection work?
- Zithromax is a broad-spectrum antibiotic.
- Zithromax attaches itself to a protein in bacteria and prevents it from working. Without this protein, cell growth stops and the bacteria eventually die.
- It is important to take the full dose of Zithromax to get rid of all the bacteria. If you don’t take the full dose, some bacteria may remain in your body, start growing again, and eventually increase in number and make you sick again.
How is Zithromax Injection used?
- A healthcare professional or a nurse will inject the medication through a needle into your vein, directly into your bloodstream.
- It will take at least one hour to administer the whole medication.
- Cannot be given as one quick shot into your vein.
- Cannot be given as a shot into your arm, abdomen, or thigh muscles.
- Medication should be discarded if there are any particles or discoloration in the diluted product.
- After your injection, your doctor may also prescribe a follow-up Zithromax to be taken orally. It is important to take this medication as prescribed and finish the full course even if you start feeling better.
- Store undiluted vials between 20°- 25°C (68° – 77°F) and keep away from direct heat or sunlight.
- When diluted, Zithromax should remain stable for:
- 24 hours at or below room temperature (30°C or 86°F).
- One week in the fridge (5°C or 41°F).
- If you are unsure about the proper storage of your medication, speak with your doctor or pharmacist.
Dosages will depend on what you are being treated for in addition to other factors. The typical recommended dose for an adult with:
- Community-Acquired Pneumonia is 500 mg as a single dose intravenously (IV) per day for at least two days. This will be followed with oral Zithromax capsule or tablet (500 mg per day) for seven to ten days.
- Pelvic Inflammatory Disease is 500 mg as a single dose intravenously (IV) per day for one or two days. This will be followed with oral Zithromax capsule or tablet (250 mg per day) for seven days.
- A nurse or healthcare professional will dilute Zithromax and prepare it for injection through a needle into your vein.
- The diluted Zithromax solution is infused slowly into your vein, so you need to sit in place for at least one hour.
- Patients are encouraged to read the Medication Guide to learn more about Zithromax injection.
- Tell your nurse or doctor if you experience any pain, redness, swelling, or discomfort at the injection site.
- If you have any questions or concerns, check with your doctor or nurse.
As with all medications, there are always some side effects that you may experience. Some are mild, while others are more serious.
Common Side Effects
- Stomach pain
- Pain or redness at the injection site
Contact your doctor if any of these side effects persist after you finish your treatment.
Serious Side Effects
Less common, but more serious side effects are also possible. Contact your doctor if you experience any of the following:
- Yellowing of the skin and eyes
- Severe abdominal pain
- Nausea or vomiting that didn’t go away or got worse after you stopped taking Zithromax
- Swelling in the feet or legs
- Dark urine
- Changes in your hearing, including hearing loss and ringing in the ears
- Changes in your vision or any eye problems
- Extreme fatigue or muscle weakness
Side Effect Details
- Diarrhea: diarrhea usually starts after starting Zithromax and ends after you stop using it. Make sure to hydrate and drink plenty of water while taking azithromycin. Do not self-treat diarrhea before speaking with a doctor or pharmacist. Sometimes patients can develop watery or bloody diarrhea even after two months of stopping Zithromax. If this happens, contact your doctor immediately.
- Yellowing of the skin and eyes and dark urine may be signs of liver damage, in which case, you may need to stop taking the medication.
- Stomach pain may be a sign of gastritis, which is an inflammation of the stomach.
- Severe abdominal pain accompanied by back pain may be a sign of pancreatitis; which is an inflammation of the pancreas.
You can also report any side effects you experience while taking Zithromax to Health Canada at 1-866-234-2345.
Warnings & Precautions
While rare, Zithromax can have serious, sometimes fatal, side effects. Some of these dangerous side effects are unavoidable, whereas others can be avoided by making sure you tell your doctor about the following:
- If you are allergic to Zithromax or other macrolide antibiotics.
- If you have any other allergies, including food allergies.
- If you ever had a bad reaction to Zithromax injection, such as yellowing of the skin or eyes, feeling dizzy, experiencing heart palpitations, fainting, swelling of skin, throat, or tongue, or difficulty breathing.
- If you have myasthenia gravis.
- If your diarrhea is caused or has ever been caused by Clostridioides difficile (C. diff).
- If you have or ever had any heart problems, including heart attacks, abnormal heart rhythm, heart failure, and prolonged QT interval.
- If you have or ever had any kidney problems.
- If you have or ever had any liver problems.
- If you have or ever had mental health problems.
- If you have low potassium (hypokalemia).
- If you have low magnesium (hypomagnesemia).
Moreover, if your doctor prescribes oral Zithromax after your injection, make sure to take it as prescribed and finish the full course even if you feel better.
- Always tell your doctor and pharmacist about all the medications you are taking, including over the counter medications, vitamins, supplements, or any other natural products.
- While many medications interact with Zithromax, special attention should be made to the following medications:
- Warfarin and other blood thinners (for blood clots)
- Digoxin (for heart failure)
- Colchicine (for gout and familial Mediterranean fever)
- Nelfinavir (for human immunodeficiency virus [HIV])
- Ergotamine and other ergot derivatives (for migraines)
- Antacids containing magnesium or aluminum (for indigestion)
- Sotalol (for atrial fibrillation and other arrythmias)
- Amiodarone and dronedarone (for atrial fibrillation)
- Chloroquine or hydroxychloroquine or (for rheumatoid arthritis, or malaria)
This is not a complete list. Always consult with a doctor or pharmacist before starting, stopping, or changing any medication.
- Zithromax is contraindicated in patients who are allergic to azithromycin or other macrolide and ketolide antibiotics, such as erythromycin and clarithromycin.
- Zithromax is contraindicated in patients who had yellowing of the skin and eyes or other signs of liver problems while previously taking this medication.
Frequently Asked Questions