<qa>  What is an estimated creatinine clearance?- An estimated creatinine clearance of 80 mlmin based on the Cockcroft-Gault equation. An actual creatinine clearance, as determined by a 24 hour urine collection, may be used in place of the Cockcroft-Gault equation. Subjects who have an actual or estimated creatinine clearance 70 mlmin may be enrolled at the discretion of the investigator. 