Alternative Oseltamivir Dosing Strategies

• Status: Completed
• Trial end date: 2007-04-10
• Target enrollment: 0
• Participant gender: All

Summary

This study will determine if oseltamivir (Tamiflu(Registered Trademark)) is safe and effective given less frequently than the currently prescribed dose of twice a day for 5 days to people who have the flu, and once a day for up to 6 weeks in people who have been exposed to someone else with flu and want to prevent getting it themselves. This study will see if the drug can be given once every other day instead of daily if given with another medication called probenecid (Benemid(Registered Trademark) or Probalan(Registered Trademark)).

Healthy people 18 years of age and older may be eligible for this study. Candidates are screened with a medical history, physical examination, and blood and urine tests.

Participants are randomly assigned to one of the following regimens for 2 weeks: 1) 75 milligrams (mg) of oseltamivir once a day; 2) 75 mg of oseltamivir once every other day plus 500 mg probenecid four times a day; or 3) 75 mg of oseltamivir once every other day plus 500 mg probenecid twice a day. All medications are taken by mouth. On study day 0, subjects have the following baseline procedures: measurement of vital signs, review of medical and medication history, physical examination, blood draw and urine test. They also receive the first dose of oseltamivir or oseltamivir and probenecid. In addition, they undergo the following procedures as follows:

• Days 1 and 4: Vital signs; review of clinical symptoms, side effects and medications taken; urine testing and blood draw.

• Day 8: Same as day 1 plus count of study medication.

• Day 14: Same as day 8 plus pharmacokinetic study to measure the amount of oseltamivir and probenecid in the blood. For this test, a catheter is inserted into an arm vein and blood samples are collected through the catheter before taking the study medications, at the time the medications are taken, and again at 15 minutes, 30 minutes, 45 minutes and 1, 1.5, 2, 4, 8 and 12 hours after the medication is taken. The catheter is then removed. This is the last day to take the study medication.

• Day 15: Blood draw for 24-hour (post medication) blood sample.

• Day 16: Blood draw for 48-hour (post medication) blood sample.

• Days 21 and 28: Same as day 1.

• Phase: Phase 2
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: National Institute of Allergy and Infectious Diseases (NIAID)
• Treatments: Oseltamivir

Criteria

• 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.

1. Hemoglobin greater than or equal to 10.0 g/dL for males and greater than 9.0 g/dL for females;

2. Platelet count of greater than or equal to 75,000 /micro L;

3. Absolute neutrophil count greater than or equal to 1000 /micro L;

4. SGOT and SGPT less than 2.5 times normal upper limit;

5. Serum uric acid WNL;

6. Creatinine less than 1.5 times normal upper limit (normal UL 1.5 mg/dL) for the less than 65 years of age group and must be within normal limits for the greater than or equal to 65 years of age group;

7. creatinine clearance greater than or equal to 50 mL/min.

EXCLUSION CRITERIA:

Subjects with a creatinine clearance of less than 50 mL/min (as measured by the Cockcroft-Gault method)

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 0 of the study

Subjects with G6PD deficiency

Subjects who may have been recently 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 any dose non-aspirin 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).