CClinicalTrials.gg
CompletedNCT00000826Updated Oct 29, 2021

Effect of Fluconazole, Clarithromycin, and Rifabutin on the Pharmacokinetics of Sulfamethoxazole-Trimethoprim and Dapsone and Their Hydroxylamine Metabolites

A Phase 1 interventional study of Clarithromycin and Rifabutin in Bacterial Infections, Mycoses and HIV Infections, sponsored by National Institute of Allergy and Infectious Diseases (NIAID). Completed at 2 sites in United States. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2021-10-29.

Sponsored by National Institute of Allergy and Infectious Diseases (NIAID) · Phase 1, Interventional, and Treatment

Phase
Phase 1
Study type
Interventional
Enrollment
48
Ages
18 Years to 65 Years
Sex
All
01

Study summary

To determine the effects of fluconazole and either rifabutin or clarithromycin, alone and in combination, on the pharmacokinetics of first sulfamethoxazole-trimethoprim and then dapsone in HIV-infected patients.

Although prophylaxis for more than one opportunistic infection is emerging as a common clinical practice in patients with advanced HIV disease, little is known about possible adverse drug interactions. The need exists to define pharmacokinetics and pharmacodynamic adverse interactions of the many combination prophylactic regimens that may be prescribed.

Read the detailed description

Although prophylaxis for more than one opportunistic infection is emerging as a common clinical practice in patients with advanced HIV disease, little is known about possible adverse drug interactions. The need exists to define pharmacokinetics and pharmacodynamic adverse interactions of the many combination prophylactic regimens that may be prescribed.

In Part A, patients receive sulfamethoxazole-trimethoprim (SMX/TMP) alone for 2 weeks, then in combination with fluconazole, rifabutin, or both drugs, each over 2-week periods in a randomly assigned order. Patients in Part B receive the same regimens except with clarithromycin substituted for rifabutin. In Part C, patients receive dapsone alone for 2 weeks, then in combination with fluconazole, rifabutin, or both drugs in the same manner as in Part A. Part D patients receive the same regimen as those in Part C, except with clarithromycin substituted for rifabutin. Patients are followed every 2 weeks.

02

Conditions studied

  • Bacterial Infections
  • Mycoses
  • HIV Infections

Keywords

  • Rifabutin
  • Trimethoprim-Sulfamethoxazole Combination
  • AIDS-Related Opportunistic Infections
  • Dapsone
  • Drug Interactions
  • Fluconazole
  • Acquired Immunodeficiency Syndrome
  • AIDS-Related Complex
  • Clarithromycin
  • Sulfamethoxazole-Trimethoprim
03

In context

Infections

6,687 studies on the registry are indexed under Infections; 807 are open to participants now.

This study's enrollment of 48 is below the median of 120 across 4,200 interventional studies indexed under Infections.

Browse Infections studies →

Lead sponsor

National Institute of Allergy and Infectious Diseases (NIAID) is the lead sponsor of 2,401 studies on the registry; 179 are open to participants now.

Of its 396 completed or terminated interventional studies of FDA-regulated products, 294 (74%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

Concurrent Medication:

Allowed:

  • Antiretroviral therapy provided patient has been on a stable dose for at least 4 weeks prior to study entry.
  • Methadone for drug abuse programs provided patient has been on a stable dose for at least 4 weeks prior to the study.

Patients must have:

  • HIV infection.
  • CD4 count >= 200 cells/mm3.
  • No active opportunistic infection.

Prior Medication:

Allowed:

  • Antiretroviral therapy.
  • Methadone for drug abuse therapy.

Exclusion criteria

Exclusion Criteria

Co-existing Condition:

Patients with the following symptoms or conditions are excluded:

  • Suspicion of gastrointestinal malabsorption problems (at discretion of investigator).
  • Known hypersensitivity to dapsone, SMX, or other sulfonamides, trimethoprim, clarithromycin, rifabutin or other rifamycins, fluconazole, or other azoles.
  • G-6-PD deficiency or methemoglobinemia (in Part C and D patients only).

Concurrent Medication:

Excluded:

  • Cytolytic agents.
  • Amiodarone.
  • Anesthetics, general.
  • Astemizole.
  • Azithromycin.
  • Barbiturates.
  • Carbamazepine.
  • Cimetidine.
  • Ciprofloxacin.
  • Cisapride.
  • Clarithromycin (except as required on study).
  • Clotrimazole.
  • Dexamethasone.
  • Disulfiram.
  • Erythromycin.
  • Fluoroquinolones.
  • Fluoxetine.
  • Gestodene.
  • Hydrochlorothiazide.
  • Hypoglycemics, oral.
  • Isoniazid.
  • Itraconazole.
  • Ketoconazole.
  • Levomepromazine.
  • Loratadine.
  • MAO inhibitors.
  • Methoxsalen.
  • Miconazole.
  • Nafcillin.
  • Narcotic analgesics.
  • Naringenin.
  • Nifedipine.
  • Norethindrone.
  • Pentazocine.
  • Phenothiazines.
  • Phenytoin.
  • Protease inhibitors.
  • Quinidine.
  • Ranitidine.
  • Rifabutin (except as required on study).
  • Rifampin.
  • Sedative hypnotics.
  • Sulfaphenazole.
  • Terfenadine.
  • Tranquilizers (unless allowed by investigator).
  • Tricyclic and tetracyclic antidepressants.
  • Troleandomycin.
  • Warfarin.

Concurrent Treatment:

Excluded:

  • Radiation therapy.

Prior Medication:

Excluded:

  • Cytolytic agents within 5 years prior to study entry.
  • Rifabutin and/or rifampin within 4 weeks prior to study entry.
  • Fluconazoles or other azoles within 4 weeks prior to study entry.
  • Glutathione, glutathione precursors, or related prodrugs within 2 weeks prior to study entry.

Excluded within 72 hours prior to study entry:

  • Amiodarone.
  • Anesthetics, general.
  • Astemizole.
  • Azithromycin.
  • Cimetidine.
  • Ciprofloxacin.
  • Cisapride.
  • Clarithromycin.
  • Dexamethasone.
  • Disulfiram.
  • Erythromycin.
  • Fluoroquinolones.
  • Fluoxetine.
  • Hydrochlorothiazide.
  • Hypoglycemics, oral.
  • Isoniazid.
  • Levomepromazine.
  • Loratadine.
  • MAO inhibitors.
  • Methoxsalen.
  • Nafcillin.
  • Narcotic analgesics.
  • Naringenin.
  • Nifedipine.
  • Norethindrone.
  • Pentazocine.
  • Phenothiazines.
  • Phenytoin.
  • Protease inhibitors.
  • Quinidine.
  • Ranitidine.
  • Sedative hypnotics.
  • Sulfaphenazole.
  • Terfenadine.
  • Tranquilizers (unless allowed by investigator).
  • Troleandomycin.
  • Warfarin.

Excluded within 4 weeks prior to study entry:

  • Barbiturates.
  • Carbamazepine.
  • Clotrimazole.
  • Gestodene.
  • Itraconazole.
  • Ketoconazole.
  • Miconazole.
  • Omeprazole.
  • Rifabutin.
  • Rifampin.
  • Tricyclic and tetracyclic antidepressants.

Prior Treatment:

Excluded:

  • Blood transfusion within 1 week prior to study entry.
  • Radiation therapy within 5 years prior to study entry.

Active drug or alcohol abuse or dependence that would preclude completion of study.

05

Study design

Phase
Phase 1
Primary purpose
Treatment
Masking
None (open label)
Enrollment
48 participants

Interventions

  • DrugClarithromycin
  • DrugRifabutin
  • DrugSulfamethoxazole-Trimethoprim
  • DrugDapsone
  • DrugFluconazole
06

Study locations

2 sites
  • Ucsf Aids Crs
    San Francisco, California, United States
  • University of Washington AIDS CRS
    Seattle, Washington 98122, United States
07

References and documents

Publications

  • Cheng B. Preventing opportunistic infections. PI Perspect. 1995 May;(no 16):14-5. PubMed 11362422 ↗
  • Winter HR, Trapnell CB, Slattery JT, Jacobson M, Greenspan DL, Hooton TM, Unadkat JD. The effect of clarithromycin, fluconazole, and rifabutin on sulfamethoxazole hydroxylamine formation in individuals with human immunodeficiency virus infection (AACTG 283). Clin Pharmacol Ther. 2004 Oct;76(4):313-22. doi: 10.1016/j.clpt.2004.06.002. PubMed 15470330 ↗
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Oct 29, 2021, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT00000826
Lead sponsor
National Institute of Allergy and Infectious Diseases (NIAID)
Responsible party
Sponsor
First posted
Aug 31, 2001
Completion
May 1999
Last update
Oct 29, 2021

Study contacts

Unadkat J
study chair
Trapnell CB
study chair
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Oct 2021. You cannot join it, but the record below documents what was studied.

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Start the discussion