Z-Pak Side Effects

Generic name: azithromycin

Medically reviewed by Drugs.com. Last updated on May 20, 2024.

Note: This document provides detailed information about Z-Pak Side Effects associated with azithromycin. Some dosage forms listed on this page may not apply specifically to the brand name Z-Pak.

Applies to azithromycin: oral powder for suspension, oral powder for suspension extended release, oral tablet.

Other dosage forms:

• intravenous powder for solution

Precautions

It is very important that your doctor check the progress of you or your child at regular visits to make sure this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

If you or your child's symptoms do not improve within a few days, or if they become worse, check with your doctor.

This medicine may cause serious allergic reactions, including anaphylaxis and angioedema, which can be life-threatening and require immediate medical attention. Call your doctor right away if you or your child have a rash, itching, hives, hoarseness, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth after you take this medicine.

Serious skin reactions, including Stevens-Johnson syndrome, acute generalized exanthematous pustulosis, toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms (DRESS) can occur with this medicine. Check with your doctor right away if you or your child have black, tarry stools, blistering, peeling, or loosening of the skin, chest pain, chills, cough, diarrhea, itching, joint or muscle pain, painful or difficult urination, red irritated eyes, red skin lesions, often with a purple center, sore throat, sores, ulcers, or white spots in the mouth or on the lips, swollen glands, unusual bleeding or bruising or unusual tiredness or weakness while you are using this medicine.

Check with your doctor right away if you or your child have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, unusual tiredness or weakness, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Call your child's doctor right away if your child feels irritable or vomits after feeding. These may be symptoms of a condition called infantile hypertrophic pyloric stenosis.

Azithromycin may cause diarrhea, and in some cases it can be severe. It may occur 2 months or more after you stop using this medicine. Do not take any medicine to treat diarrhea without first checking with your doctor. Diarrhea medicines may make the diarrhea worse or make it last longer. If you or your child have any questions about this or if mild diarrhea continues or gets worse, check with your doctor.

This medicine can cause changes in heart rhythms, including QT prolongation. It may change the way your heart beats and cause fainting or serious side effects in some patients. Contact your doctor right away if you or your child have any symptoms of heart rhythm problems, including fast, pounding, or irregular heartbeats.

This medicine may increase the risk of serious heart or blood vessel problems. Call your doctor right away if you have blurred vision, chest pain, confusion, lightheadedness, dizziness, fainting, fast or irregular heartbeat, trouble breathing, or unusual tiredness or weakness.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Serious side effects of Z-Pak

Along with its needed effects, azithromycin (the active ingredient contained in Z-Pak) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking azithromycin:

Other side effects of Z-Pak

Some side effects of azithromycin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to azithromycin: intravenous powder for injection, oral capsule, oral powder for reconstitution, oral powder for reconstitution extended release, oral tablet.

General adverse events

The most commonly reported side effects were diarrhea/loose stools, nausea, abdominal pain, and vomiting.^[Ref]

Cardiovascular

• Uncommon (0.1% to 1%): Palpitations, chest pain
• Postmarketing reports: Torsades de pointes, arrhythmia (including ventricular tachycardia), ECG QT prolonged, hypotension, cardiovascular death

Dermatologic

• Common (1% to 10%): Rash, pruritus
• Uncommon (0.1% to 1%): Angioedema, photosensitivity reaction, Stevens-Johnson syndrome, urticaria, dermatitis, dry skin, hyperhidrosis/sweating
• Rare (0.01% to 0.1%): Acute generalized exanthematous pustulosis, drug reaction with eosinophilia and systemic symptoms (DRESS)
• Frequency not reported: Eczema, fungal dermatitis, vesiculobullous rash
• Postmarketing reports: Toxic epidermal necrolysis, erythema multiforme, serious skin reactions

Gastrointestinal

• Very common (10% or more): Diarrhea (up to 52.8%), nausea (up to 32.6%), abdominal pain (up to 32.2%), loose stools (up to 19.1%), vomiting (up to 13%), flatulence (up to 10.7%), abdominal discomfort
• Common (1% to 10%): Dyspepsia, stomatitis
• Uncommon (0.1% to 1%): Gastritis, gastroenteritis, oral candidiasis/moniliasis, constipation, dysphagia, abdominal distension, dry mouth, eructation, mouth ulceration, salivary hypersecretion
• Frequency not reported: Clostridioides difficile-associated diarrhea, melena, infantile hypertrophic pyloric stenosis, mucositis, enteritis
• Postmarketing reports: Pyloric stenosis, pseudomembranous colitis, pancreatitis, tongue discoloration

Genitourinary

• Common (1% to 10%): Vaginitis/vaginal infection
• Uncommon (0.1% to 1%): Dysuria, metrorrhagia, testicular disorder

Hematologic

• Very common (10% or more): Decreased neutrophils (up to 29%)
• Common (1% to 10%): Decreased lymphocyte count, decreased hematocrit, decreased hemoglobin, increased eosinophil count, increased platelet count, increased lymphocytes, increased basophils, increased monocytes, increased neutrophils
• Uncommon (0.1% to 1%): Leukopenia, neutropenia, eosinophilia
• Frequency not reported: Decreased white cell count, decreased platelet count, anemia
• Postmarketing reports: Thrombocytopenia, hemolytic anemia

Hepatic

• Common (1% to 10%): Increased AST, increased ALT, increased GGT, increased blood bilirubin
• Uncommon (0.1% to 1%): Hepatitis, abnormal liver function tests
• Rare (0.01% to 0.1%): Abnormal hepatic function, cholestatic jaundice
• Frequency not reported: Liver enzyme abnormalities, increased transaminase levels, jaundice
• Postmarketing reports: Hepatic failure, fulminant hepatitis, hepatic necrosis

Hepatic failure has rarely resulted in death.

Hypersensitivity

• Uncommon (0.1% to 1%): Hypersensitivity
• Postmarketing reports: Anaphylactic reaction/anaphylaxis (e.g., anaphylactic shock), allergic reactions

Severe (rarely fatal) anaphylactic reaction has been reported.

Local

• Common (1% to 10%): IV site pain, injection site inflammation (with IV administration), IV site disorders (infection/inflammation/edema/pain reactions), local inflammation, infusion site reaction
• Frequency not reported: Local inflammation at infusion site

Metabolic

• Common (1% to 10%): Decreased blood bicarbonate, anorexia, decreased blood glucose, increased blood glucose
• Uncommon (0.1% to 1%): Increased bicarbonate
• Postmarketing reports: Dehydration

Musculoskeletal

• Common (1% to 10%): Arthralgia, increased creatine phosphokinase
• Uncommon (0.1% to 1%): Osteoarthritis, myalgia, back pain, neck pain

Nervous system

• Common (1% to 10%): Headache, dizziness, paresthesia, dysgeusia
• Uncommon (0.1% to 1%): Somnolence, hypesthesia, tinnitus, vertigo
• Frequency not reported: Hyperkinesia
• Postmarketing reports: Syncope, convulsion, psychomotor hyperactivity, anosmia, ageusia, parosmia, myasthenia gravis, hyperactivity

Ocular

• Common (1% to 10%): Visual impairment, abnormal vision
• Frequency not reported: Conjunctivitis, blurred vision

Other

• Very common (10% or more): Increased blood alkaline phosphatase (up to 20%)
• Common (1% to 10%): Deafness, fatigue, increased potassium, increased lactate dehydrogenase, reversible hearing impairment
• Uncommon (0.1% to 1%): Candidiasis/moniliasis, ear disorder, asthenia, malaise, chest pain, edema, hearing impaired, abnormal blood potassium, fungal infection, bacterial infection, hot flush, face edema, pyrexia/fever, pain, peripheral edema, increased chloride, abnormal sodium, postprocedural complications
• Frequency not reported: Increased phosphate, decreased sodium, decreased potassium
• Postmarketing reports: Hearing disturbances (including hearing loss, deafness, tinnitus)

Psychiatric

• Uncommon (0.1% to 1%): Nervousness, insomnia
• Rare (0.01% to 0.1%): Agitation, depersonalization
• Frequency not reported: Delirium, hallucination
• Postmarketing reports: Aggression/aggressive reaction, anxiety

Renal

• Common (1% to 10%): Increased blood urea/BUN, increased blood creatinine
• Uncommon (0.1% to 1%): Renal pain
• Frequency not reported: Nephritis, renal function abnormality
• Postmarketing reports: Acute renal failure, interstitial nephritis

Respiratory

• Common (1% to 10%): Dyspnea
• Uncommon (0.1% to 1%): Pneumonia, pharyngitis, rhinitis, respiratory disorder, epistaxis
• Frequency not reported: Bronchospasm, cough, pleural effusion

See also:

Frequently asked questions

• What are the best antibiotics for a tooth infection?
• What antibiotics kill Covid-19 (coronavirus)?
• What is the best antibiotic to treat strep throat?
• Does azithromycin cure chlamydia: How much / how long?
• How long does azithromycin stay in your system?
• What are the best antibiotics for pneumonia?
• What antibiotics are used to treat chlamydia and gonorrhea?
• Can you drink alcohol with Z-Pak (Azithromycin)?
• Was azithromycin in my system long enough to treat chlamydia after throwing up?

Further information

Z-Pak side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer