Drug Interaction Study of Azithromycin and Theophylline

A Pharmacokinetic Drug Interaction Study to Evaluate the Effect of Azithromycin on the Steady-State Plasma Levels of Theophylline in a Chinese Population

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT02023554

Enrollment

Registered

2013-12-30

Start date

2013-12-31

Completion date

2014-07-31

Last updated

2014-08-19

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

Conditions

Asthma, Chronic Obstructive Pulmonary Disease

Keywords

azithromycin, theophylline, CYP3A4

Brief summary

Macrolides are potent inhibitors of cytochrome P450 isoenzyme 3A4（CYP3A4）and thus interfere with the pharmacokinetics of many other drugs that are metabolised by this enzyme like theophylline.The aim of this study is to determine whether azithromycin can effect theophylline metabolism in patients.

Detailed description

In this non-blinded,auto-control study,patients with Chronic Obstructive Pulmonary Disease（COPD）or asthma will serve as their own controls during the 2-week treatment phase.The subjects will be co-administered oral doses of sustained release theophylline (100mg tablets,twice daily) and azithromycin (2x250mg capsules,once daily )in the first week.Then patients will received theophylline therapy alone with the same dose in the second week.Blood samples for the measurement of theophylline plasma concentrations will be collected on Days 8 and 15 prior to dosing.All adverse events whether elicited by query, spontaneously reported or observed by clinic staff will be evaluated by the investigator and reported in the subject's case report form.

Interventions

DRUGTheophylline with azithromycin

Drug: Theophylline(100mg,sustained release tablets). Multi-dose of theophylline(100mg,twice daily) will administered at 8 am and 8 pm from day 1 to day 7. Drug:Azithromycin(250mg, capsules). Multi-dose of azithromycin(500mg,once daily) will administered at 8 pm from day 1 to day 7.

DRUGTheophylline alone

Drug: Theophylline(100mg,sustained release tablet). Multi-dose of theophylline(100mg,twice daily) will administered at 8 am and 8 pm from day 8 to day 14.

Study design

Allocation

NON_RANDOMIZED

Intervention model

SINGLE_GROUP

Primary purpose

BASIC_SCIENCE

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to 75 Years

Healthy volunteers

Inclusion criteria

* patients with COPD or asthma，aged 18-75 years; * regularly visiting our hospital; * meeting the indications for azithromycin and theophylline simultaneously;

Exclusion criteria

* patients with renal or hepatic dysfunction; * patients with congestive heart failure; * patients with hypothyroidism or hyperthyroidism; * patients taking drugs likely to affect the theophylline metabolism in the preceding week; * patients with severe chronic obstructive pulmonary disease,asthma or respiratory infection;

Design outcomes

Primary

Measure	Time frame	Description
steady-state plasma concentration of theophylline	blood samples for theophylline will be collected on Days 8 and 15 before dosing	Theophylline and it's metabolite(1,3-dimethyluric) blood concentration

Countries

China

Outcome results

None listed

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