From the article:
Lead researcher Marc Kaufman and his colleagues first established the rate of blood flow to the brain in male and female occasional cocaine users. An intravenous dose of cocaine (0.4 mg/kg) was administered to nine men and 13 women. Men were studied once while women were examined during different phases of their menstrual cycle phases (days 3-8, follicular phase and 18-24, leutial phase) after the beginning of menstruation.
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In the follicular phase, when estrogen levels are high and progesterone levels are low, cocaine did not alter the amount of blood in the brain. By contrast, a 10 percent reduction in blood was found in women during their luteal menstrual cycle phase, when progesterone levels rise; male subjects incurred a 20 percent loss. These findings suggest that cocaine’s effects on blood vessels in the brain differ as a function of sex and menstrual cycle phase, and imply that progesterone in women and testosterone in men may enhance cocaine-induced vasoconstriction, while estrogen in women may blunt cocaine’s vascular effects.
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Such benefits could extend beyond drug using populations. For example, treatments that improve brain blood flow might also benefit the elderly, many of whom experience reductions of blood flow to the brain as a result of aging.