Drug Sentencing Reform Act of 2001 - Amends the Controlled Substances Act and the Controlled Substances Import and Export Act to decrease the amount of powder cocaine and increase the amount of crack cocaine necessary to trigger the mandatory minimum penalties relating to the trafficking in, and possession, importation, or distribution of, cocaine.

Directs the United States Sentencing Commission to amend the sentencing guidelines to ensure: (1) that guideline offense levels based upon the quantity of powder cocaine and crack cocaine are consistent with this Act, and that they provide an additional penalty increase of from two to eight levels if the defendant used or credibly threatened violence, or possessed a dangerous weapon, during the course of a drug trafficking offense; (2) an additional increase of at least two levels if the defendant has a leadership role (as specified) in drug trafficking activity involving super-aggravating factors; and (3) that there be a limit on sentence (as specified) when the defendant has a lesser role.

Requires the Director of the Bureau of Prisons to carry out a pilot program at one or more designated facilities to place each eligible prisoner on home detention until the date on which that prisoner's term of imprisonment expires. Defines "eligible prisoner" as a prisoner who is at least 65 years old, has not been determined by the Bureau to have a history of violence, and meets other specified criteria.

Grants the Commission certain emergency amendment authority.