Z-Pak Side Effects
Generic Name: azithromycin
Note: This document contains side effect information about azithromycin. Some of the dosage forms listed on this page may not apply to the brand name Z-Pak.
For the Consumer
Applies to azithromycin: intravenous powder for solution
Other dosage forms:
Side effects requiring immediate medical attention
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 or nurse immediately if any of the following side effects occur while taking azithromycin:
- Pain, redness, and swelling at the injection site
- Difficult or labored breathing
- loose stools
- tightness in the chest
- Abdominal or stomach cramps or pain (severe)
- abdominal or stomach tenderness
- diarrhea (watery and severe, which may be bloody)
- joint pain
- skin rash
- swelling of the face, mouth, neck, hands, and feet
Incidence not known
- black, tarry stools
- bleeding gums
- blistering, peeling, or loosening of the skin
- blood in the urine or stools
- bloody or cloudy urine
- blurred vision
- chest pain or discomfort
- darkened urine
- decreased urine output
- difficulty with swallowing
- dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
- fast, pounding, or irregular heartbeat or pulse
- fever with or without chills
- general feeling of discomfort or illness
- greatly decreased frequency of urination or amount of urine
- hives or itching
- increased thirst
- irregular heartbeat recurrent
- irregular or slow heart rate
- large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
- light-colored stools
- loss of appetite
- muscle pain
- muscle twitching
- nausea or vomiting
- pains in the stomach, side, or abdomen, possibly radiating to the back
- pinpoint red spots on the skin
- puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
- rapid weight gain
- red skin lesions, often with a purple center
- red, irritated eyes
- sore throat
- sores, ulcers, or white spots in the mouth or on the lips
- swelling of the hands, ankles, feet, or lower legs
- unusual bleeding or bruising
- unusual tiredness or weakness
- yellow eyes or skin
Side effects not requiring immediate medical attention
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:
- Diarrhea (mild)
- stomach pain or discomfort (mild)
- weight loss
Less common or rare
- Acid or sour stomach
- burning feeling in the chest or stomach
- cracked lips
- excess air or gas in the stomach or intestines
- full feeling
- passing gas
- sleepiness or unusual drowsiness
- sore mouth or tongue
- stomach discomfort, upset, or pain
- white patches in the mouth, tongue, or throat
Incidence not known
- Attack, assault, or force
- bad, unusual, or unpleasant (after) taste
- burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
- change in taste
- continuing ringing or buzzing or other unexplained noise in the ears
- difficulty with moving
- discoloration of the tongue
- dizziness or lightheadedness
- feeling of constant movement of self or surroundings
- hearing loss
- itching of the vagina or genital area
- lack or loss of strength
- loss of sense of smell
- muscle pain or stiffness
- pain during sexual intercourse
- sensation of spinning
- thick, white vaginal discharge with no odor or with a mild odor
- 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
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%), flatulence (up to 10.7%)
Postmarketing reports: Pyloric stenosis[Ref]
Common (1% to 10%): Decreased lymphocyte, hematocrit, hemoglobin, or neutrophil count, increased eosinophil count, increased platelets, hematocrit, lymphocytes, basophils, monocytes, or neutrophils
Common (1% to 10%): Headache, dizziness, paresthesia, dysgeusia
Uncommon (0.1% to 1%): Somnolence, hypesthesia
Postmarketing reports: Hyperactivity[Ref]
Common (1% to 10%): Deafness, fatigue
Uncommon (0.1% to 1%): Candidiasis, ear disorder, asthenia, malaise, face edema, pyrexia, pain, post procedural complications, hearing disturbances/impairment, tinnitus, laboratory abnormalities, fungal or bacterial infection
Postmarketing reports: Hearing loss, taste/smell perversion and/or loss[Ref]
Common (1% to 10%): Rash, pruritus
Very rare (less than 0.01%): Drug reaction of eosinophilia and systemic symptoms (DRESS)
Common (1% to 10%): Decreased blood bicarbonate, anorexia
Uncommon (0.1% to 1%): Abnormal sodium, increased blood alkaline phosphatase, bicarbonate, or chloride
Frequency not reported: Increased lactate dehydrogenase, decreased sodium or potassium
Common (1% to 10%): Dyspnea
Common (1% to 10%): Arthralgia
Common (1% to 10%): Vaginitis/vaginal infection
Common (1% to 10%): Allergic reaction
Uncommon (0.1% to 1%): Angioedema, hypersensitivity
Postmarketing reports: Fatal anaphylaxis[Ref]
Common (1% to 10%): Visual impairment
Uncommon (0.1% to 1%): Hepatitis, increased AST, ALT, GGT, or blood bilirubin
Frequency not reported: Hepatic failure/fatal hepatic failure, fulminant hepatitis, hepatic necrosis[Ref]
Uncommon (0.1% to 1%): Palpitations, hot flush, edema, chest pain, peripheral edema
Uncommon (0.1% to 1%): Nervousness, insomnia
Rare (0.01% to 0.1%): Agitation
Uncommon (0.1% to 1%): Renal pain, increased blood urea nitrogen and creatinine
Frequency not reported: Acute renal failure, interstitial nephritis/nephritis[Ref]
Frequency not reported: Moniliasis, flu syndrome[Ref]
1. "Product Information. Zithromax injection (azithromycin)" Pfizer US Pharmaceuticals, New York, NY.
2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
3. "Product Information. Zithromax (azithromycin)." Pfizer US Pharmaceuticals, New York, NY.
4. "Product Information. Azithromycin Product Information (azithromycin)." Pfizer US Pharmaceuticals, New York, NY.
5. Cerner Multum, Inc. "Australian Product Information." O 0
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Some side effects may not be reported. You may report them to the FDA.
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More about Z-Pak (azithromycin)
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Interactions
- Support Group
- 16 Reviews
- Drug class: macrolides
- FDA Alerts (3)