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Zithromax (Azithromycin) - Side Effects and Adverse Reactions

 
 



ADVERSE REACTIONS

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%. (See DOSAGE AND ADMINISTRATION.) Most of the side effects leading to discontinuation were related to the gastrointestinal tract, e.g., nausea, vomiting, diarrhea, or abdominal pain. (See CLINICAL STUDIES IN PEDIATRIC PATIENTS.)

Clinical

Adults

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.

Pediatric Patients

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. (See DOSAGE AND ADMINISTRATION and CLINICAL STUDIES IN PEDIATRIC PATIENTS.)

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

Dosage
Regimen
Diarrhea, % Abdominal
Pain, %
Vomiting, % Nausea, % Rash, %
1-day 4.3% 1.4% 4.9% 1.0% 1.0%
3-day 2.6% 1.7% 2.3% 0.4% 0.6%
5-day 1.8% 1.2% 1.1% 0.5% 0.4%

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:

Dosage
Regimen
Diarrhea/Loose stools, % Abdominal
Pain, %
Vomiting, % Nausea, % Rash, %
5-day 5.8% 1.9% 1.9% 1.9% 1.6%

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:

Dosage
Regimen
Diarrhea, % Abdominal Pain, % Vomiting, % Nausea, % Rash, % Headache, %
5-day 5.4% 3.4% 5.6% 1.8% 0.7% 1.1%

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, pyloric stenosis, 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: Adverse reactions related to hepatic dysfunction have been reported in postmarketing experience with azithromycin. (See WARNINGS, Hepatotoxicity.)

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

Adults

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.

Pediatric Patients

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. (See DOSAGE AND ADMINISTRATION.)

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



REPORTS OF SUSPECTED ZITHROMAX SIDE EFFECTS / ADVERSE REACTIONS

Below is a sample of reports where side effects / adverse reactions may be related to Zithromax. The information is not vetted and should not be considered as verified clinical evidence.

Possible Zithromax side effects / adverse reactions in 41 year old female

Reported by a health professional (non-physician/pharmacist) from France on 2011-10-04

Patient: 41 year old female

Reactions: Extrasystoles, Drug Interaction, Bradycardia

Suspect drug(s):
Zithromax

Other drugs received by patient possibly interacting with the suspect drug:
Ivabradine
    Dosage: unk
    Start date: 2011-09-16

Ivabradine
    Dosage: 10 mg, 1x/day
    Administration route: Oral
    End date: 2011-09-11



Possible Zithromax side effects / adverse reactions in 48 year old female

Reported by a physician from Japan on 2011-10-06

Patient: 48 year old female weighing 53.9 kg (118.6 pounds)

Reactions: Polymyositis, Pruritus, Pyrexia, Rash

Adverse event resulted in: hospitalization

Suspect drug(s):
Zithromax

Other drugs received by patient: Zithromax; Garenoxacin Mesilate



Possible Zithromax side effects / adverse reactions in 50 year old female

Reported by a pharmacist from Japan on 2011-10-07

Patient: 50 year old female

Reactions: Abdominal Pain, Loss of Consciousness

Suspect drug(s):
Zithromax



See index of all Zithromax side effect reports >>

Drug label data at the top of this Page last updated: 2011-03-11

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