A Multicenter, Randomized, Double-Blind, Double-Dummy Comparative Trial of Azithromycin Sustained Release Versus 3-Day Azithromycin for the Treatment of Strep Throat in Adolescents and Adults

A Multicenter, Randomized, Double-Blind, Double-Dummy Comparative Trial of Azithromycin SR Versus Three-Day Azithromycin for the Treatment of Group A β-Hemolytic Streptococcal Pharyngitis/Tonsillitis in Adolescents and Adults

Status

Completed

Phases

Phase 3

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00644293

Enrollment

598

Registered

2008-03-26

Start date

2003-01-31

Completion date

2004-04-30

Last updated

2011-06-08

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Pharyngitis, Tonsillitis

Brief summary

To determine if a single 2.0-g dose of azithromycin SR is at least as effective as a 3-day course of azithromycin (500 mg once daily for 3 days) when used to treat adolescents and adults with strep throat, and to assess efficacy and safety for both treatment regimens.

Interventions

DRUGazithromycin (Zithromax)

azithromycin 500 mg tablet by mouth once daily for 3 days

DRUGplacebo

placebo

DRUGazithromycin SR

azithromycin SR 2.0 g by mouth as an oral slurry for 1 dose

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender

ALL

Age

13 Years to No maximum

Healthy volunteers

Inclusion criteria

* Patients with evidence of acute group A beta-hemolytic streptococcus (GABHS) pharyngitis/tonsillitis and a positive rapid antigen detection test or positive culture of the pharynx or tonsils for GABHS

Exclusion criteria

* Patients were excluded if they had treatment with any systemic antibiotic within the previous 7 days, a history of rheumatic fever, a peritonsillar abcess, or were known carriers of GABHS.

Design outcomes

Primary

Measure	Time frame
bacteriologic response in the Bacteriologic per Protocol population	Test of Cure (TOC) visit (Days 24-28)

Secondary

Measure	Time frame
bacteriologic response for the remaining study populations	TOC visit
sponsor assessment of clinical response for the Bacteriologic per Protocol population	Long-Term Follow-Up (LTFU) visit (Days 38-45)
sponsor assessment of clinical response in the Bacteriologic per Protocol population	TOC visit
summary of baseline susceptibilities	Study endpoint
adverse events	Continuous
bacteriologic response for the Bacteriologic per Protocol population	TOC visit

Countries

Belgium, Finland, France, Germany, India, Italy, Netherlands, Norway, United Kingdom, United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026