Evaluation of Alternative Oseltamivir (Tamiflu) Dosing Strategies.

This study has been completed.
Brooke Army Medical Center
National Institutes of Health (NIH)
Information provided by:
VA Office of Research and Development
ClinicalTrials.gov Identifier:
First received: March 16, 2006
Last updated: September 21, 2009
Last verified: September 2009
Objective 1: Determine the safety and toxicity profile of Tamiflu administered in combination with probenecid in healthy adults.Objective 2: Determine the pharmacokinetic profile of Tamiflu and probenecid in healthy adults.

Condition Intervention Phase
Drug: Oseltamivir
Drug: Probenecid
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Pharmacokinetics Study
Intervention Model: Parallel Assignment
Masking: Open Label
Official Title: Oseltamivir (Tamiflu) Dosing Strategies for Use During Influenza Prophylaxis (VA01)

Resource links provided by NLM:

Further study details as provided by VA Office of Research and Development:

Primary Outcome Measures:
  • To determine whether the combination of oseltamivir and probenecid result in equivalent blood plasma concentrations compared to oseltamivir given alone [ Time Frame: 15 days ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • The safety of combining oseltamivir and probenecid [ Designated as safety issue: Yes ]

Estimated Enrollment: 48
Study Start Date: February 2005
Study Completion Date: February 2007
Primary Completion Date: February 2007 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
1 Drug: Oseltamivir Drug: Probenecid

Detailed Description:

In vitro studies have determined that the 50 % inhibitory concentrations (IC50) of Ro 64-0802 against influenza neuraminidases ranged from 0.3 to 22 nmol/L (0.08 - 0.28 g/L or 0.08 -0.28 ng/mL). IC50 values against influenza strains in cell culture were somewhat higher and more variable ranging from 0.6 to 155 nmol/L (0.17 - 32.8 g/L or 0.17 - 32.8 ng/mL). Tamiflu has also been shown to have in vitro and mouse challenge activity against the H5N1 virus. EC50 values against H5N1 strain replication in Madin Darby canine kidney (MDCK) cells ranged from 7.5-12 M and neuraminidase activity from 7.0-15 nM (IC50 values).

The current U.S. FDA approved recommendations for influenza A and B treatment using oseltamivir suggest a dose of 75mg taken orally twice daily for 5 days at the onset of symptoms or laboratory confirmation of infection. Prophylaxis against influenza A infection for those people exposed to or at high risk for exposure suggests a dose of 75 mg orally taken once daily for up to 6 weeks. No clinical trials in humans infected with or requiring prophylaxis for the H5N1 variant have been performed. Oseltamivir treatment in a human pediatric case of H5N1 influenza pneumonia has been published. Oseltamivir was given late in the course of illness and the child subsequently expired. Several people were given a prophylactic course of oseltamivir after avian influenza (H7N7, H7N3) outbreaks in the Netherlands and in British Columbia, which appeared to be effective in preventing additional human cases.

Clinical trials using oseltamivir for influenza treatment have recently been reviewed. Two phase III placebo controlled, blinded studies were performed in adults, three in geriatric populations, and one in pediatric patients. In general, flu symptoms were decreased by one day or greater in those patients who received Tamiflu compared to placebo. Several prophylaxis studies using oseltamivir have been conducted in healthy unvaccinated adults and have also been recently reviewed. In several trials involving either prophylaxis after household exposure or after exposure in the community have demonstrated that the incidence of influenza was significantly reduced (range 70-90%) in those patients receiving Tamiflu, 75mg orally once daily for 42 days compared to placebo. Side effect profiles in the prophylaxis studies indicate that nausea and vomiting were more commonly found in the Tamiflu arm when compared to placebo. There was no difference in side effect incidence in younger compared to older adult (> 65 years) populations.


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

Subjects will include males and non-pregnant females 18 years or older Subjects who can understand the study and potential safety concerns and can sign the informed consent form prior to admission to this study Subjects that are willing to complete all the required assessments, tests and evaluations and able to make all study visits Hemoglobin > 10.0 g/dL for males and > 9.0 g/dL for females; b) Platelet count of > 75,000 / L; c) Absolute neutrophil count > 1000 / L; SGOT and SGPT < than 2.5 times normal upper limit (UL); Serum uric acid WNL; Creatinine < 1.5 times normal upper limit (normal UL 1.5 mg/dL) for the < 65 years of age group and MUST be WNL for the > 65 years of age group; creatinine clearance > 50 mL/min

Exclusion Criteria:

Subjects with a creatinine clearance of < 50 mL/min Subjects who are pregnant or breast feeding females Subjects who are not employing adequate contraception Subjects who are drug or alcohol abusers and in the opinion of the investigator would interfere with subject compliance and safety Subjects who are currently participating in any other clinical research study Any acute serious infection requiring prescription therapy within 14 days prior to Day 1 of the study Subjects who may have or recently been exposed to influenza Subjects with gout, blood dyscrasias, or history of hypersensitivity to sulfonamide drugs Subjects with contraindications to the study medications History of allergic reaction to probenecid Have kidney disease, kidney stones, or poorly functioning kidneys Have active peptic ulcer disease On high dose aspirin or salicylate therapy

Receiving any of the following medications (relative contraindication for probenecid):

Acyclovir, allopurinol, penicillamine, clofibrate, rifampin, methotrexate, zidovudine, theophylline, dapsone, penicillins or cephalosporins, nonsteroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen (Motrin, Advil, Nuprin, others), ketoprofen (Orudis, Oruvail, Orudis KT), diclofenac (Cataflam, Voltaren), etodolac (Lodine), fenoprofen (Nalfon), flurbiprofen (Ansaid), indomethacin (Indocin), ketorolac (Toradol), nabumetone (Relafen), oxaprozin (Daypro), piroxicam (Feldene), sulindac (Clinoril), tolmetin (Tolectin), and naproxen (Aleve, Anaprox, Naprosyn); a sulfa-based medication such as sulfamethoxazole (Bactrim, Septra, Gantanol), sulfasalazine (Azulfidine), sulfinpyrazone (Anturane), sulfisoxazole (Gantrisin), and others; an oral diabetes medicine such as glipizide (Glucotrol), glyburide (Micronase, Diabeta, Glynase), tolbutamide (Orinase), or tolazamide (Tolinase); a barbiturate such as phenobarbital (Luminal, Solfoton), amobarbital (Amytal), secobarbital (Seconal), and others; or a benzodiazepine (used to treat anxiety and panic disorders and to induce sleep) such as alprazolam (Xanax), diazepam (Valium), lorazepam (Ativan), temazepam (Restoril), chlordiazepoxide (Librium), clonazepam (Klonopin), clorazepate (Tranxene), oxazepam (Serax), estazolam (ProSom), flurazepam (Dalmane), quazepam (Doral), or triazolam (Halcion).

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Please refer to this study by its ClinicalTrials.gov identifier: NCT00304434

United States, California
VA Palo Alto Health Care System
Palo Alto, California, United States, 94304-1207
Sponsors and Collaborators
VA Office of Research and Development
Brooke Army Medical Center
National Institutes of Health (NIH)
Principal Investigator: Mark Holodniy, MD VA Palo Alto Health Care System
  More Information

Responsible Party: Holodniy, Mark - Principal Investigator, Department of Veterans Affairs
ClinicalTrials.gov Identifier: NCT00304434     History of Changes
Other Study ID Numbers: INDA-014-05F 
Study First Received: March 16, 2006
Last Updated: September 21, 2009
Health Authority: United States: Federal Government
United States: Food and Drug Administration

Keywords provided by VA Office of Research and Development:
Adverse effects
Clinical trial

Additional relevant MeSH terms:
Anti-Infective Agents
Antirheumatic Agents
Antiviral Agents
Enzyme Inhibitors
Gout Suppressants
Molecular Mechanisms of Pharmacological Action
Pharmacologic Actions
Renal Agents
Therapeutic Uses
Uricosuric Agents

ClinicalTrials.gov processed this record on February 11, 2016