Z-Pak Side Effects

Generic name: azithromycin

Medically reviewed by Drugs.com. Last updated on Dec 15, 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

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:

More common side effects

• diarrhea
• loose stools

Less common side effects

• blistering, crusting, irritation, itching, or reddening of the skin
• cracked, dry, or scaly skin
• fever
• swelling

Rare side effects

• blistering, peeling, or loosening of the skin
• bloody or cloudy urine
• bloody, black, or tarry stools
• body aches or pain
• burning while urinating
• chest pain or tightness
• chills
• congestion
• cough increased
• cough producing mucus
• dark urine
• difficult or labored breathing
• difficult or painful urination
• dizziness
• drowsiness
• dryness or soreness of the throat
• earache
• fainting
• fast, irregular, pounding, or racing heartbeat or pulse
• general feeling of discomfort or illness
• headache
• indigestion
• irregular or slow heart rate
• itching or rash
• joint or muscle pain
• large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
• light-colored stools
• loss of appetite
• muscle aches and pains
• nausea or vomiting
• noisy breathing
• passing of gas
• red skin lesions, often with a purple center
• red, irritated eyes
• redness or swelling in the ear
• runny nose
• shivering
• sneezing
• sores, ulcers, or white spots on the lips or in the mouth
• stomach pain, continuing
• stomach pain, fullness, or discomfort
• stuffy nose
• sweating
• swelling of the face, ankles, hands, feet, or lower legs
• tender, swollen glands in the neck
• trouble with sleeping
• trouble with swallowing
• unpleasant breath odor
• unusual bleeding or bruising
• unusual tiredness or weakness
• upper right abdominal or stomach pain
• voice changes
• vomiting of blood
• yellow eyes or skin

Incidence not known

• bleeding gums
• bloating
• blood in the urine or stools
• blurred vision
• change in hearing
• clay-colored stools
• coma
• confusion
• constipation
• continuing ringing or buzzing or other unexplained noise in the ears
• decreased urine output
• depression
• diarrhea, watery and severe, which may also be bloody
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• fainting
• greatly decreased frequency of urination or amount of urine
• hives
• hostility
• increased thirst
• irritability
• lethargy
• loss of hearing
• lower back or side pain
• muscle twitching
• no blood pressure or pulse
• pains in the stomach, side, or abdomen, possibly radiating to the back
• pale skin
• pinpoint red spots on the skin
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• rapid weight gain
• seizures
• stomach cramps or tenderness
• stopping of heart
• stupor
• unconsciousness
• unusual weight loss

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:

Rare side effects

• acid or sour stomach
• aggressive or angry
• bad, unusual, or unpleasant (after) taste
• belching
• burning feeling in the chest or stomach
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• change in taste
• changes in the color of the tongue
• crying
• depersonalization
• dry mouth
• dysphoria
• euphoria
• excess air or gas in the stomach or intestines
• feeling of constant movement of self or surroundings
• full feeling
• heartburn
• hyperventilation
• increase in body movements
• itching of the vagina or genital area
• lack or loss of strength
• mental depression
• nervousness
• pain during sexual intercourse
• paranoia
• quick to react or overreact emotionally
• rapidly changing moods
• rash with flat lesions or small raised lesions on the skin
• redness of the skin
• restlessness
• sensation of spinning
• shaking
• sleepiness or unusual drowsiness
• stomach upset
• thick, white vaginal discharge with no odor or with a mild odor
• white patches in the mouth, tongue, or throat

Incidence not known

• difficulty with moving
• increased sensitivity of the skin to sunlight
• muscle pain or stiffness
• pain in the joints
• redness or other discoloration of the skin
• severe sunburn
• trouble sitting still

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

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