Zithromax Side Effects

Generic Name: azithromycin

Please note - some side effects for Zithromax may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA at http://www.fda.gov/medwatch/ or 1-800-FDA-1088 (1-800-332-1088).

Side Effects of Zithromax - for the Consumer

Zithromax

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Zithromax:

Diarrhea; headache; loose stools; nausea; stomach pain; upset stomach; vomiting.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue; unusual hoarseness); bloody stools; changes in hearing or hearing loss; chest pain; eye or vision problems; irregular heartbeat; muscle weakness; pounding in the chest; red, swollen, blistered, or peeling skin; ringing in the ears; seizure; severe diarrhea; stomach cramps/pain; trouble speaking or swallowing; yellowing of the skin or eyes.

Zithromax Single-Dose Packet

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Zithromax Single-Dose Packet:

Diarrhea; headache; loose stools; nausea; stomach pain; upset stomach; vomiting.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue; unusual hoarseness); bloody stools; changes in hearing or hearing loss; chest pain; eye or vision problems; irregular heartbeat; muscle weakness; pounding in the chest; red, swollen, blistered, or peeling skin; ringing in the ears; seizure; severe diarrhea; stomach cramps/pain; trouble speaking or swallowing; yellowing of the skin or eyes.

Zithromax Suspension

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Zithromax Suspension:

Diarrhea; headache; loose stools; nausea; stomach pain; upset stomach; vomiting.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue; unusual hoarseness); bloody stools; changes in hearing or hearing loss; chest pain; eye or vision problems; irregular heartbeat; muscle weakness; pounding in the chest; red, swollen, blistered, or peeling skin; ringing in the ears; seizure; severe diarrhea; stomach cramps/pain; trouble speaking or swallowing; yellowing of the skin or eyes.

Zithromax Tablets

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Zithromax Tablets:

Diarrhea; headache; loose stools; nausea; stomach pain; upset stomach; vomiting.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue; unusual hoarseness); bloody stools; changes in hearing or hearing loss; chest pain; eye or vision problems; irregular heartbeat; muscle weakness; pounding in the chest; red, swollen, blistered, or peeling skin; ringing in the ears; seizure; severe diarrhea; stomach cramps/pain; trouble speaking or swallowing; yellowing of the skin or eyes.

Zithromax Side Effects - for the Professional

Zithromax

In clinical trials, most of the reported side effects were mild to moderate in severity and were reversible upon discontinuation of the drug. Potentially serious side effects of angioedema and cholestatic jaundice were reported rarely. Approximately 0.7% of the patients (adults and pediatric patients) from the 5-day multiple-dose clinical trials discontinued Zithromax (azithromycin) therapy because of treatment-related side effects. In adults given 500 mg/day for 3 days, the discontinuation rate due to treatment-related side effects was 0.6%. In clinical trials in pediatric patients given 30 mg/kg, either as a single dose or over 3 days, discontinuation from the trials due to treatment-related side effects was approximately 1%. Most of the side effects leading to discontinuation were related to the gastrointestinal tract, e.g., nausea, vomiting, diarrhea, or abdominal pain.

Clinical

Multiple-dose regimens

Overall, the most common treatment-related side effects in adult patients receiving multiple-dose regimens of Zithromax were related to the gastrointestinal system with diarrhea/loose stools (4–5%), nausea (3%) and abdominal pain (2–3%) being the most frequently reported.

No other treatment-related side effects occurred in patients on the multiple-dose regimens of Zithromax with a frequency greater than 1%. Side effects that occurred with a frequency of 1% or less included the following:

Cardiovascular: Palpitations, chest pain.

Gastrointestinal: Dyspepsia, flatulence, vomiting, melena and cholestatic jaundice.

Genitourinary: Monilia, vaginitis and nephritis.

Nervous System: Dizziness, headache, vertigo and somnolence.

General: Fatigue.

Allergic: Rash, pruritus, photosensitivity and angioedema.

Single 1-gram dose regimen

Overall, the most common side effects in patients receiving a single-dose regimen of 1 gram of Zithromax were related to the gastrointestinal system and were more frequently reported than in patients receiving the multiple-dose regimen.

Side effects that occurred in patients on the single one-gram dosing regimen of Zithromax with a frequency of 1% or greater included diarrhea/loose stools (7%), nausea (5%), abdominal pain (5%), vomiting (2%), dyspepsia (1%) and vaginitis (1%).

Single 2-gram dose regimen

Overall, the most common side effects in patients receiving a single 2-gram dose of Zithromax were related to the gastrointestinal system. Side effects that occurred in patients in this study with a frequency of 1% or greater included nausea (18%), diarrhea/loose stools (14%), vomiting (7%), abdominal pain (7%), vaginitis (2%), dyspepsia (1%) and dizziness (1%). The majority of these complaints were mild in nature.

Single and Multiple-dose regimens

The types of side effects in pediatric patients were comparable to those seen in adults, with different incidence rates for the  dosage regimens recommended in pediatric patients.

Acute Otitis Media: For the recommended total dosage regimen of 30 mg/kg, the most frequent side effects (≥1%) attributed to treatment were diarrhea, abdominal pain, vomiting,  nausea and rash.

The incidence, based on dosing regimen, is described in the table below:

Community-Acquired Pneumonia

For the recommended dosage regimen of 10 mg/kg on Day 1 followed by 5 mg/kg on Days 2–5, the most frequent side effects attributed to treatment were diarrhea/loose stools, abdominal pain, vomiting, nausea and rash.

The incidence is described in the table below:

Pharyngitis/tonsillitis

For the recommended dosage regimen of 12 mg/kg on Days 1–5, the most frequent side effects attributed to treatment were diarrhea, vomiting, abdominal pain, nausea and headache.

The incidence is described in the table below:

With any of the treatment regimens, no other treatment-related side effects occurred in pediatric patients treated with Zithromax with a frequency greater than 1%. Side effects that occurred with a frequency of 1% or less included the following:

Cardiovascular: Chest pain.

Gastrointestinal: Dyspepsia, constipation, anorexia, enteritis, flatulence, gastritis, jaundice, loose stools and oral moniliasis.

Hematologic and Lymphatic: Anemia and leukopenia.

Nervous System: Headache (otitis media dosage), hyperkinesia, dizziness, agitation, nervousness and insomnia.

General: Fever, face edema, fatigue, fungal infection, malaise and pain.

Allergic: Rash and allergic reaction.

Respiratory: Cough increased, pharyngitis, pleural effusion and rhinitis.

Skin and Appendages: Eczema, fungal dermatitis, pruritus, sweating, urticaria and vesiculobullous rash.

Special Senses: Conjunctivitis.

Post-Marketing Experience

Adverse events reported with azithromycin during the post-marketing period in adult and/or pediatric patients for which a causal relationship may not be established include:

Allergic: Arthralgia, edema, urticaria and angioedema.

Cardiovascular: Arrhythmias including ventricular tachycardia and hypotension. There have been rare reports of QT prolongation and torsades de pointes.

Gastrointestinal: Anorexia, constipation, dyspepsia, flatulence, vomiting/diarrhea rarely resulting in dehydration, pseudomembranous colitis, pancreatitis, oral candidiasis and rare reports of tongue discoloration.

General: Asthenia, paresthesia, fatigue, malaise and anaphylaxis (rarely fatal).

Genitourinary: Interstitial nephritis and acute renal failure and vaginitis.

Hematopoietic: Thrombocytopenia.

Liver/Biliary: Abnormal liver function including hepatitis and cholestatic jaundice, as well as rare cases of hepatic necrosis and hepatic failure, some of which have resulted in death.

Nervous System: Convulsions, dizziness/vertigo, headache, somnolence, hyperactivity, nervousness, agitation and syncope.

Psychiatric: Aggressive reaction and anxiety.

Skin/Appendages: Pruritus, rarely serious skin reactions including erythema multiforme, Stevens Johnson Syndrome and toxic epidermal necrolysis.

Special Senses: Hearing disturbances including hearing loss, deafness and/or tinnitus and reports of taste/smell perversion and/or loss.

Laboratory Abnormalities

Clinically significant abnormalities (irrespective of drug relationship) occurring during the clinical trials were reported as follows: with an incidence of greater than 1%: decreased hemoglobin, hematocrit, lymphocytes, neutrophils and blood glucose; elevated serum creatine phosphokinase, potassium, ALT, GGT, AST, BUN, creatinine, blood glucose, platelet count, lymphocytes, neutrophils and eosinophils; with an incidence of less than 1%: leukopenia, neutropenia, decreased sodium, potassium, platelet count, elevated monocytes, basophils, bicarbonate, serum alkaline phosphatase, bilirubin, LDH and phosphate. The majority of subjects with elevated serum creatinine also had abnormal values at baseline.

When follow-up was provided, changes in laboratory tests appeared to be reversible.

In multiple-dose clinical trials involving more than 5000 patients, four patients discontinued therapy because of treatment-related liver enzyme abnormalities and one because of a renal function abnormality.

One, Three and Five Day Regimens

Laboratory data collected from comparative clinical trials employing two 3-day regimens (30 mg/kg or 60 mg/kg in divided doses over 3 days), or two 5-day regimens (30 mg/kg or 60 mg/kg in divided doses over 5 days) were similar for regimens of azithromycin and all comparators combined, with most clinically significant laboratory abnormalities occurring at incidences of 1–5%. Laboratory data for patients receiving 30 mg/kg as a single dose were collected in one single center trial.  In that trial, an absolute neutrophil count between 500–1500 cells/mm3 was observed in 10/64 patients receiving 30 mg/kg as a single dose, 9/62 patients receiving 30 mg/kg given over 3 days, and 8/63 comparator patients. No patient had an absolute neutrophil count <500 cells/mm3.

In multiple-dose clinical trials involving approximately 4700 pediatric patients, no patients discontinued therapy because of treatment-related laboratory abnormalities.

Side Effects by Body System

Gastrointestinal

Gastrointestinal side effects have included nausea, abdominal discomfort, vomiting, and diarrhea in up to 10% of patients. However, patients rarely (less than 1%) discontinued therapy due to these side effects. Dyspepsia, flatulence, mucositis, oral moniliasis, constipation, melena, and gastritis have been reported with a frequency of 1% or less. Pseudomembranous colitis has been reported with nearly all antibacterial agents and may range in severity from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea subsequent to the administration of azithromycin. Anorexia, vomiting/diarrhea rarely resulting in dehydration, pancreatitis, and rare reports of tongue discoloration have been reported during postmarketing experience.

Hypersensitivity

Reappearance of allergic symptoms may occur without further azithromycin exposure when symptomatic therapy is discontinued. This phenomenon may be related to the long tissue half-life of the drug. Patients experiencing allergic symptoms may require prolonged periods of observation and symptomatic treatment.

Hypersensitivity side effects have rarely included angioedema, anaphylaxis, Stevens-Johnson syndrome, and toxic epidermal necrolysis. Toxic pustuloderma with fever has been reported in at least one patient receiving azithromycin. There is also an isolated report of azithromycin-induced hypersensitivity syndrome. Allergic reactions (including arthralgia, edema, urticaria, and angioedema) and anaphylaxis (rarely fatal) have been reported during postmarketing experience.

Cardiovascular

Cardiovascular side effects have rarely included arrhythmias (including ventricular tachycardia), prolongation of the QT interval, torsades de pointes, palpitations, hypotension, and chest pain in postmarketing experience. A causal relationship has not been established.

Hepatic

Hepatic side effects have infrequently included transient elevations of liver function tests (including AST and ALT) and elevated bilirubin. Hepatitis and cholestatic jaundice, as well as rare cases of hepatic necrosis and hepatic failure (some resulting in death), have been reported during postmarketing experience.

Local

Local side effects associated with intravenous administration of the drug have included pain at injection site (6.5%) and local inflammation (3.1%).

Nervous system

Nervous system side effects have included headache, somnolence, vertigo, and dizziness in approximately 1% of patients. Hearing disturbances including hearing loss, deafness, and/or tinnitus have been reported rarely. Paresthesia, convulsions, hyperactivity, nervousness, agitation, and syncope have been reported during postmarketing experience.

Other

Other side effects have included asthenia. Taste/smell perversion and/or loss (rare), fatigue, and malaise have been reported during postmarketing experience.

Renal

Renal side effects have rarely included elevations in serum creatinine and blood urea nitrogen. Interstitial nephritis and acute renal failure have been reported during postmarketing experience. Interstitial nephritis resulting in permanent renal failure has been reported in a patient receiving azithromycin monotherapy.

Hematologic

Hematologic side effects have included decreased lymphocytes, increased eosinophils, leukopenia, and neutropenia. Thrombocytopenia has been reported during postmarketing experience.

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