Cohorts 1 to 4 received a first dose of 50 mg of GS-5806 and then 25 mg daily for the next 4 days , cohort 5 received a first dose of 50 mg and then 25 mg daily for the next 2 days , cohort 6 received one 100-mg dose , and cohort 7 received a first dose of 10 mg and then 5 mg daily for the next 4 days .