Drug Interactions | Influence of Rifampin Co-Administration on the Pharmacokinetic Profile of Daptomycin

Drug Interactions research study

What is the primary objective of this study?

The purpose of this study is to understand how an antibiotic, rifampin, may change the blood levels of another antibiotic, daptomycin, in the body. In addition, the effect of polymorphisms in P-glycoprotein (a protein involved in the removal of daptomycin from the body) on the blood levels of daptomycin will be evaluated. The hypotheses are that rifampin will decrease the blood levels of daptomycin and that the effect will be greater for certain P-glycoprotein polymorphisms.

Who is eligible to participate?

Inclusion Criteria: - Ability to provide informed consent - If female of child bearing potential, on reliable method of contraception and negative pregnancy test at enrollment Exclusion Criteria: - Obesity (body mass index > 30) - Creatinine clearance < 80 ml/min - Creatine phosphokinase > 2 times upper limit of normal at enrollment - Aspartate aminotransferase, alanine aminotransferase, or alkaline phosphatase > 3 times upper limit of normal at enrollment - History of liver disease or cirrhosis - History of congestive heart failure - Allergy or intolerance to rifampin or daptomycin - Need for concomitant non-study medications during the study period - Inability to abstain from grapefruit juice or herbal supplements (such as St. John's wort) during the study period - Receipt of study drugs within 30 days prior to enrollment - Pregnancy or lactation - Inability to adhere to study procedures

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?

Drug Interactions


Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.



Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.

Daptomycin and RifampinDrug: Daptomycin Daptomycin 6 mg/kg will be given by IV infusion on the first study day Drug: Rifampin Rifampin 600 mg capsules will be given orally once daily for 14 days starting on study day 2 Drug: Daptomycin Daptomycin 6 mg/kg will be given by IV infusion on study day 15

Study Status


Start Date: May 2014

Completed Date: July 2016

Phase: Early Phase 1

Type: Interventional


Primary Outcome: Daptomycin total, renal, and non-renal clearance

Secondary Outcome: P-glycoprotein Polymorphism

Study sponsors, principal investigator, and references

Principal Investigator: Russell Benefield, Pharm.D.

Lead Sponsor: University of Utah

Collaborator: Cubist Pharmaceuticals LLC

More information:

Discuss Rifampin