Pfizer Corporation Hong Kong Limited 美國輝瑞科研製藥

Indications¹

Zmax™ is indicated for the treatment of mild to moderate infections caused by susceptible isolates of the designated microorganisms in the following conditions:

Acute bacterial sinusitis (ABS) in adults due to Haemophilus influenzae, Moraxella catarrhalis or Streptococcus pneumoniae
Community acquired pneumonia (CAP) in adults and pediatric patients 6 months of age or older due to Chlamydophila pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae or S. pneumoniae, where oral therapy is appropriate

Clinical Evidence

Zmax™ single dose is as effective as 7-day levofloxacin and extended-release clarithromycin for CAP^2,3

Two randomized, double-blind, double dummy, multicenter studies compared the efficacy and safety of Zmax™ 2 g with either levofloxacin (500 mg qd x 7 days) or extended-release clarithromycin (1 g qd x 7 days) in patients with CAP.

Clinical and bacteriologic responses were assessed at the test of cure visit (day 13-24) in the clinical per protocol population.² Clinical and bacteriologic responses were assessed as the test of cure visit (day 14-21) in the clinical per protocol population.³

Cure was defined as resolution of signs and symptoms related to the acute infection or clinical improvement such that no additional antibiotics were deemed necessary, and the chest X-ray performed at the test of cure visit was to be either improved or stable.^2,3

Bacteriologic success was defined as eradication and presumed eradication.^2,3
Zmax™ single dose is as effective as 10-day levofloxacin for ABS⁴

A randomized, double-blind, double-dummy, multicenter study, compared the efficacy and safety of Zmax™ 2 g with levofloxacin (500 mg qd x 10 days) in the treatment of ABS.⁴

Clinical and bacteriologic responses were assessed at the test of cure visit (day 17-24) in the clinical per protocol population. All patients underwent maxillary sinus aspiration prior to treatment.⁴

Cure was defined as resolution of signs and symptoms related to the acute infection or clinical improvement such that no additional antibiotics were deemed necessary.⁴

Safety Profile¹

CONTRAINDICATIONS: Zmax™ is contraindicated in patients with known hypersensitivity to azithromycin, erythromycin or any macrolide or ketolide antibiotic.

SAFETY PRECAUTIONS: Serious allergic reactions, including angioedema, anaphylaxis, Stevens-Johnson syndrome and toxic epidermal necrolysis are rarely reported in patients on azithromycin therapy using other formulations. Despite initially successful symptomatic treatment of the allergic symptoms, when symptomatic therapy was discontinued, the allergic symptoms recurred soon thereafter in some patients without further azithromycin exposure. These patients required prolonged periods of observation and symptomatic treatment. Clostridium difficile-associated diarrhea (CDAD) must be considered in patients with diarrhea following antibiotic use. Exacerbation of symptoms of myasthenia gravis and new onset of myasthenic syndrome in patients receiving azithromycin therapy may be observed. If a patient vomits between 5 and 60 minutes following administration, alternative therapy should be considered. Caution should be exercised in patients with a glomerular filtration rate (GFR) <10 mL/min, due to a higher incidence of gastrointestinal adverse events. Prolonged cardiac repolarization and QT interval, imparting a risk of developing cardiac arrhythmia and torsades de pointes in treatment with macrolides, have been reported. Prescribing Zmax™ in the absence of a proven or strongly suspected bacterial infection is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria. Carefully monitor patients when digoxin, ergotamine or dihydroergotamine, cyclosporine, hexobarbital and phenytoin are used concomitantly with azithromycin.

SIDE EFFECTS:
Adults – Common side effects include diarrhea/loose stools, nausea, abdominal pain, headache, vomiting. Less common side effects include palpitation and arrhythmias including ventricular tachycardia and hypotension, chest pain, constipation, dyspepsia, flatulence, gastritis, oral moniliasis, vaginitis, dizziness, vertigo, asthenia, rash, pruritus, urticaria, taste perversion.
Pediatric patients in clinical trials – Common side effects include vomiting, diarrhea, loose stools, abdominal pain, nausea, rash, dermatitis, anorexia, fever. Less common side effects include chills, flu syndrome, headache, abnormal stools, constipation, dyspepsia, flatulence, gastritis, gastrointestinal disorder, hepatitis, leucopenia, agitation, emotional liability, hostility, hyperkinesia, insomnia, irritability, parasthesia, somnolence, asthma, bronchitis, cough worsening, dyspnea, pharyngitis, rhinitis, fungal dermatitis, maculopapular rash, pruritus, urticaria, otitis media, taste perversion, dysuria.

INTERACTIONS: Prothrombin times should be carefully monitored while patients are receiving azithromycin and oral anticoagulants (eg, warfarin) concomitantly. Azithromycin had minimal effect on the pharmacokinetics of atorvastatin, carbamazepine, cetirizine, didanosine, efavirenz, fluconazole, indinavir, midazolam, sildenafil, theophylline (intravenous and oral), triazolam, trimethoprim/sulfamethoxazole or zidovudine. Co-administration of nelfinavir increases azithromycin serum concentration.

PREGNANCY and LACTATION: Pregnancy Category B – Zmax™ has teratogenic effects; it should only be used during pregnancy if clearly needed. It is not known whether azithromycin is excreted in human milk; caution should be exercised when administered to a nursing woman.

Dosages¹

Adults: Zmax&trade should be taken as a single 2 g dose. Zmax&trade' provides a full course of antibacterial therapy in a single oral dose.

Pediatric patients 6 months and older: Zmax™ should be taken as a single dose of 60 mg/kg (equivalent to 27 mg/lb) body weight. The Zmax™ dose in mL is equivalent to the child’s weight in pounds (1 mL/lb dose), for a body weight of less than 75 lbs (34 kg). Pediatric patients weighing 75 lbs (34 kg) or more should receive the adult dose (2 g). It is recommended that Zmax™ be taken on an empty stomach (at least 1 hour before or 2 hours following a meal). Constituted suspension should be consumed within 12 hours.

Strengths¹

Each bottle of Zmax™ contains azithromycin dihydrate equivalent to 2 g of azithromycin.
After constitution with 60 mL of water, each mL of suspension contains 27 mg of azithromycin. The suspension is a white or off-white color and has a cherry/banana flavor.

Packing¹

2 g per bottle

Please refer to the full prescribing information for more safety information.

References

1. Zmax™ (azithromycin extended release) Prescribing Information. Pfizer Corporation Hong Kong Limited: 17 September 2010

2. D’Ignazio J, Camere MA, Lewis DE, Jorgensen D, Breen JD. Novel, single-dose microsphere formulation of azithromycin versus 7-day levofloxacin therapy for treatment of mild to moderate community-acquired pneumonia in adults. Antimicrob Agents Chemother 2005;49:4035-4041.

3. Drehobl MA, De Salvo MC, Lewis DE, Breen JD. Single-dose azithromycin microspheres vs clarithromycin extended release for the treatment of mild-to-moderate community-acquired pneumonia in adults. Chest 2005:128:2230-2237.

4. Murray JJ, Emparanza P, Lesinskas E, et al. Efficacy and safety of a novel, single-dose azithromycin microsphere formulation versus 10 days of levofloxacin for the treatment of acute bacterial sinusitis in adults. Otolaryngol Head Neck Surg 2005;133:194-201.

Please review the full product information or package insert before prescribing.

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