Men who drink five or more drinks in a row and women who drink four or more drinks in a row are engaging

This would be binge drinking.

Generally, the rate of binge drinking would be 5 or more drinks for men, and 4 or more drinks for women.

The reason why women's rate is lower is because the alcohol gets into their blood stream faster then when men drink it, so it has more of an effect.

Of course, this rule doesn't apply to every single person out there. Many people have more of a tolerance, or are less sensitive to alcohol. It varies.