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Pharmacokinetics of Oseltamivir Carboxylate In Morbidly Obese Subjects

This study has been completed.
Information provided by (Responsible Party):
Amit.Pai, Albany College of Pharmacy and Health Sciences Identifier:
First received: August 10, 2010
Last updated: January 28, 2013
Last verified: April 2011
One in three Americans are obese. Obese subjects may or may not need higher doses of the anti-flu drug known as Tamiflu (oseltamivir). The current study is being done to see if the t FDA approved dose of oseltamivir will achieve similar concentrations in obese healthy volunteers compared that previously shown in non-obese volunteers.

Condition Intervention Phase
Drug: Tamiflu
Phase 1
Phase 2

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Endpoint Classification: Pharmacokinetics Study
Intervention Model: Single Group Assignment
Masking: Open Label

Resource links provided by NLM:

Further study details as provided by Albany College of Pharmacy and Health Sciences:

Primary Outcome Measures:
  • Plasma Pharmacokinetics [ Time Frame: 6 months ] [ Designated as safety issue: No ]
    To characterize the single-dose plasma pharmacokinetics of oseltamivir carboxylate administered by mouth in obese subjects.

Secondary Outcome Measures:
  • Comparison of pharmacokinetic data in obese subjects to historical data [ Time Frame: 6 months ] [ Designated as safety issue: No ]
    To compare the single and multiple-dose plasma pharmacokinetics of oseltamivir carboxylate administered by mouth in obese subjects to normal weight subjects

Enrollment: 21
Study Start Date: July 2010
Study Completion Date: December 2010
Primary Completion Date: September 2010 (Final data collection date for primary outcome measure)
Intervention Details:
    Drug: Tamiflu
    Capsule, 75 mg by mouth for 9 doses
Detailed Description:

The incidence of obesity has increased dramatically over the past two decades in the United States (US). Twenty-five percent of adult Americans are now classified as obese. Obesity is associated with physiological alterations that can affect drug clearance and volume of distribution. Obese subjects are often excluded from phase 1 pharmacokinetic studies. As a result, drug dosing regimens developed for clinical use may not be appropriate for the obese population. Use of fixed dosing regimens may result in under dosing of obese patients. In contrast adjustment of drug dosing based on total body weight may lead to over dosing of obese patients. Oseltamivir phosphate (Tamiflu®) is an antiviral agent that is currently dosed as 75 mg once daily for chemoprophylaxis and twice daily for treatment of influenza in adults.

Oseltamivir is rapidly converted to its active metabolite, oseltamivir carboxylate by esterases. The clearance of oseltamivir carboxylate is dependent on tubular secretion and glomerular filtration. Given that these drug elimination pathways may be enhanced in obese individuals, oseltamivir carboxylate plasma exposures may be lower in obese subjects compared to normal weight subjects. Although a specific plasma exposure target for oseltamivir carboxylate has not been established, lower oseltamivir carboxylate exposures may predispose obese patients to treatment failure and increase the probability for emergence of oseltamivir-resistant influenza virus. The current study proposes to characterize the plasma oseltamivir carboxylate concentration-time profile after single and multiple doses of oral oseltamivir in a cohort of healthy morbidly obese subjects. The study will be performed using a phase 1, open-label,single and multiple dose, pharmacokinetic study design in twenty obese adult subjects. This pilot study will provide pharmacokinetic data that may be incorporated into existing oseltamivir carboxylate population pharmacokinetic models to define appropriate doses of oseltamivir in obese patients.


Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • males and females, 18 to 50 years of age
  • non-smoking or light-smoking (≤5 cigarettes per day) volunteers
  • BMI ≥ 40 kg/m2
  • female subjects of childbearing potential either surgically sterilized, using an effective method of contraception (diaphragm, cervical cap,condom) or agree to abstain from sex from time of pre-study screening, during entire study period and 1 week following the study period.

Exclusion Criteria:

  • history of significant hypersensitivity reaction to oseltamivir
  • history of gastric bypass surgical procedure
  • history of significant clinical illness requiring pharmacological management
  • abnormal serum electrolyte or complete blood count requiring further clinical work-up
  • transaminases (AST or ALT) >2.5 x upper limit of normal
  • estimated creatinine clearance <50 mL/min (Cockcroft-Gault equation)
  • positive urine pregnancy test (if female)
  • abnormal electrocardiogram (ECG) as judged by study physician
  • unable to tolerate venipuncture and multiple blood draws
  • clinically significant abnormal physical examination defined as a physical finding requiring further clinical work-up
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Please refer to this study by its identifier: NCT01179919

United States, New Jersey
TKL Research
Paramaus, New Jersey, United States, 07652
Sponsors and Collaborators
Albany College of Pharmacy and Health Sciences
Principal Investigator: Manjunath Pai, PharmD ACPHS
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Amit.Pai, Associate Professor, Albany College of Pharmacy and Health Sciences Identifier: NCT01179919     History of Changes
Other Study ID Numbers: 10-002 
Study First Received: August 10, 2010
Last Updated: January 28, 2013
Health Authority: United States: Food and Drug Administration

Keywords provided by Albany College of Pharmacy and Health Sciences:
Pharmacokinetics in Obesity

Additional relevant MeSH terms:
Nutrition Disorders
Body Weight
Signs and Symptoms
Antiviral Agents
Anti-Infective Agents
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action processed this record on September 30, 2016