His health, her health

Eyeview
By David Charbonneau
January 18, 2018 - 5:00am

KAMLOOPS — Medications affect women differently than men but you wouldn’t know it from prescribed drugs.

Take the sleep drug Ambien, for example. After the drug had been placed on the market, it was found to have a dramatically different effect on women. The U.S. Food and Drug Administration found that five times as many women were experiencing driving impairment eight hours after taking the drug. As a result, doctors now prescribe “sex-specific” Ambien which is a lower dose. In Canada, the drug is sold under the name Sublinox. But sex-specific prescriptions are the exception rather than the rule.

Doctors prescribe the same drugs for men and women even though they have only been tested on men. Researchers have known about this weakness of drug trials for a long time. Dr. Marcia Stefanick, professor of medicine at Stanford University explains:

“Indeed, drug metabolism, tolerance, side effects and benefits differ significantly between the average man and woman for many widely prescribed medications, with women having a 50 to 70 per cent higher chance of adverse reaction (Scientific American, September, 2017).”

Despite knowing of the difference, few women are included in trials. In a review of 258 trials of cardiovascular treatments, only 27 per cent of the participants were women, and of those only one-third were reported by sex.

Despite years of “Red Dress” campaigns, most people and many physicians still think heart disease is a man’s disease. They are surprised to learn that heart disease is the number-one killer of women, far exceeding deaths from breast cancer. Physicians are less familiar with the symptoms of heart disease in women. In men, the main symptom is chest pain, whereas in women symptoms can include back pain, nausea, headache and dizziness. Women’s symptoms are seen as “atypical” because men don’t report them.

Chauvinistic blindness excludes half the population.

Heart disease also involves the buildup of plaque in the arteries. Men, and older women, tend to suffer from a blockage in one location. Younger women are more likely to have diffuse plaque along the entire artery with the same effect. Because a local block is not found in a younger woman, she could be diagnosed as “free from of heart disease” even though at risk of a fatal heart attack.

The other sex is sometimes overlooked in trials. Men are often neglected in studies for ailments thought to be unique to women. Osteoporosis, characterized by reduced bone strength, is considered a woman’s disease because white women are twice as likely to suffer a bone fracture as white men. As a result, fracture prevention trials include few men. But one-third of hip fractures are in men – and they have worse medical outcomes than women

Men are more susceptible to viral, bacterial, parasitic and fungal infections than women; the exception being sexually transmitted infections such as HIV and herpes which are more prevalent in women. However, women’s resistance to infection comes at a price. Women constitute 70 per cent of cases where a robust immune system attacks her own body in autoimmune diseases.

Professor Stefanick lauds the Canadian Institutes of Health Research for promoting the inclusion of sex and gender in drug trials and wishes the U.S. government would do the same. She adds:

“We need further mandates, through policy and funding restrictions, to ensure that female biology makes it into textbooks and testing protocols.”