A Pharmacokinetics, Pharmacodynamics and Safety Study of Warfarin in Combination With Tamiflu (Oseltamivir)

Roche

Status and phase: Completed; Phase 4

Conditions: Drug Therapy, Combination

Treatments: Drug: Warfarin; Drug: Oseltamivir

Study type: Interventional

Funder types: Industry

Identifiers

NCT02780622

WP21272

2007-005037-11 (EudraCT Number)

Details and patient eligibility

About

This is an open-label, randomized, 2-period crossover study, to evaluate the pharmacokinetics, pharmacodynamics, safety and tolerability of warfarin in combination with Tamiflu (oseltamivir) in participants stabilized on warfarin. Participants will be randomized to receive either their warfarin followed oseltamivir and warfarin, or by oseltamivir and warfarin followed by warfarin. The treatment periods will be separated by a washout period of at least 4 days. Participants will continue receiving warfarin once daily at a prescribed usual dose throughout the study.

Enrollment: 20 patients

Sex: All

Ages: 18 to 75 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Participants must have been receiving warfarin once daily for at least 4 weeks prior to Screening
• Participants must have regular International Normalized ratio (INR) monitoring during warfarin therapy prior to study entry, and be willing to be trained in the use of CoaguCheck devices
• INR must fall within a target range of 2.0-3.5
• Body mass index (BMI) between 18-32 kg/m^2 inclusive

Exclusion criteria

• An INR value between screening and Day -1 lower than 2.0 or greater than 3.5
• A change in prescribed daily warfarin dose between Screening and Day -1
• History of any coagulopathy
• Consumption of health products or supplements containing vitamin K
• Pregnant or lactating women
• Confirmed positive urine and/or blood test for drugs of abuse at Screening or Day -1

Trial design

20 participants in 2 patient groups

First Warfarin Then Warfarin and Oseltamivir

Experimental group

Description:

Participants will receive warfarin (on Days 1-5) in Treatment Period 1, followed by a washout period of at least 4 days (maximum 8 days). Participants will then receive oseltamivir 75 milligram (mg) (orally twice daily on Days 1-4 and once on Day 5) and warfarin in Treatment Period 2, and attend a follow-up visit 4-12 days after the last dose in Treatment Period 2. Participants will continue receiving warfarin once daily at a prescribed usual dose throughout the study.

Treatment:

Drug: Oseltamivir

Drug: Warfarin

First Warfarin and Oseltamivir Then Warfarin

Experimental group

Description:

Participants will receive oseltamivir 75 mg (orally twice daily on Days 1-4 and once on Day 5) and warfarin in Treatment Period 1, followed by a washout period of at least 4 days (maximum 8 days). Participants will then receive warfarin (on Days 1-5) in Treatment Period 2, and attend a follow-up visit 4-12 days after the last dose in Treatment Period 2. Participants will continue receiving warfarin once daily at a prescribed usual dose throughout the study.

Treatment:

Drug: Oseltamivir

Drug: Warfarin