It’s a punch line, an icon, the star of TV commercials that once evoked embarrassed chuckles. Viagra - the little blue pill celebrating its 10th birthday - continues to pack a potent punch, and not only in the bedroom. It and other erectile dysfunction drugs have become ingrained in pop culture and, as a result, may be changing how a nation of men thinks and acts on issues of health. “They’ve done a real service to men’s health,” says Scott Williams, a spokesman for the Men’s Health Network advocacy group of Viagraand its two younger competitors, Levitra and Cialis. Interest in these medications serves as a portal to other men’s health issues, such as high cholesterol, high blood pressure, diabetes and cardiovascular disease because it gets men talking to their doctor, Williams says. About 70 percent of the time, erectile dysfunction, or ED, “is the outward sign that there’s something else going on inside.” Doctors at the Mayo Clinic agree. The clinic last month published a paper suggesting a connection between ED and heart disease. “Seeing your doctor for erectile dysfunction may have a silver lining,” they say. Such links make sense if you look at the roots of the now famous diamond-shaped pill. Researchers for Pfizer pharmaceuticals were testing compounds to treat high blood pressure and cardiovascular chest pain when they discovered their volunteers developed an unintended side effect: erections. The reason: the drug enhanced the effects of nitric oxide, a chemical that relaxes smooth muscles in the penis and allows for increased blood flow. Pfizer shifted gears and asked the Food and Drug Administration to consider the drug for the medical treatment of erectile dysfunction - a condition affecting 15 million to 30 million American men, says the National Institutes of Health. Its approval as a prescription drug in 1998 created an immediate blockbuster. Within the first year, an estimated 2.6 million mentions of the drug were made during physician office visits, the National Ambulatory Medical Care Survey showed. Since then, 35 million men have popped a Viagra. It’s unclear how many men are getting prescriptions for ED drugs from a physician, versus buying pills from one of the plethora of Internet sites that advertise them. Either way, they’re being bought and used. In 2007, combined sales of Viagra, Levitra and Cialis totaled more than $3 billion. Viagra also is now approved for treating pulmonary hypertension. Salvatore Giorgianni, director of external relations when Pfizer introduced Viagra, says the drug triggered a sexual revolution much like the one ignited by women’s contraceptive pills decades earlier. Pfizer’s team knew there would be an immediate impact on pop culture and, sure enough, Jay Leno kicked it off with a joke on “The Tonight Show.” Still, the product’s image evolved from a playboy potion to an “enabling technology,” he says. That’s reinforced by the evolution of the product’s marketing: advertisements are more likely to address sexual satisfaction in addition to erectile dysfunction.