How should one take care of a loved one addicted to crack?

Be tough: Often the kindest thing is to let them take the full consequences of their mistake. If / when they are ready to get into a treatment program, be very supportive and also firm -- let them know the behavior you will not tolerate. If you make their life easy so that they can continue the habit, it is likely to kill them.

Focus on yourself.: It is important to understand that addiction is a disease; and that we should try to have compassion for those with the disease as we would anyone else who had a health problem. You did not cause your loved one's addiction, you cannot control it, and you cannot cure it. Please seek help for yourself. There are groups such as nar-anon and al-anon for those who love people with addictions.