Women at risk due to a Failure to adequately test Drugs on Women

An issue that is finally getting attention is the fact that women have been grossly underrepresented in health research and drug trials, for as long as these studies have been conducted. The result of this huge imbalance is that women are commonly being given pharmaceutical products and treatments that were only or largely tested on men and may be inappropriate, ineffective or even dangerous when prescribed to women. 

In a June 6, 2016 CBC News report, a U.B.C. professor of endocrinology, Dr. Jerilynn Prior stated that “men are not adequate replacements for women in research” and due to the different physiology of men and women, it’s not scientifically correct to apply conclusions from studies based on trials using only one gender to the other.  This is a serious problem, according to Dr. Prior, because half of the human population does not have accurate data about the outcome to any intervention.  This is a very real concern even in Canadian studies.  The Canadian Institutes of Health Research has a policy requiring researchers to reveal how they are dealing with gender when they apply for research grants, and yet, it’s rare that half the participants in any trial are women, says Prior.

There can be dangerous consequences for this imbalance in trial participants because women often respond differently to medications, according to a 2016 report in the British Journal of Sports Medicine.  The report reviewed 1383 research studies involving over 6 million sport and exercise medicine trial participants and found that 61 per cent were men and only 39 per cent were women.  In the past, women were left out of studies due to concerns over potentially harming an unborn fetus and also because they were “more physiologically variable” than their male counterparts.  Even now, a major barrier in including women in clinical trials is the perception that the fluctuation in hormonal levels during the menstrual cycle adds an unwanted element of complexity to a study and its findings.

There is sexism even in the choice of mice used in medical and drug research.  On April 20, 2016, CBC News reported that the vast majority of studies are done on male rats and mice.  In a criticism of this practice, a McGill University neurologist and pain specialist, Jeffrey Mogil, stated that there are many reasons to believe that women and men don’t respond the same to different drugs, but there have been few studies conducted to investigate this circumstance.  Dr. Mogil calls the failure to conduct research equally on female subjects “an ethical lapse” and says many drugs may not be effective at all on women.

Impact on the effectiveness and safety of medication and treatments for women

In about 80 per cent of published studies on pain research, male mice or rats are used which is clearly problematic when you consider that 70 per cent of chronic pain sufferers are women.  Perhaps even more disturbing than ineffective medication is the fact that drugs tested only on men may be found to be harmful to women.

Dr. Jerilynn Prior warns that there is evidence that woman are nearly twice as likely to have a negative reaction to drugs than men.  An accountability study carried out in the U.S. found that about 80 per cent of drugs are withdrawn after being introduced to the market because they have unacceptable side-effects for women.  Dr. Prior explains that metabolic differences and how a drug is released or excreted may vary significantly between women and men, which can create unexpected risk factors if a trial involves only one gender.

On CBC’s The Current, the scientific director of the Institute of Gender and Health at the Canadian Institutes of Health Research, Cara Tannenbaum, cited several examples involving more harmful side-effects for drugs when used by women.  One of these concerned cisapride or Prepulsid, a stomach drug sold in the 1990’s which was later withdrawn by Health Canada because it sometimes resulted in irregular heartbeats and sudden death, but only among women. A 15-year old girl died while on the medication, and there was no evidence that the drug was tested on female animals or children. Another drug that proved to be dangerous for women is a sleeping pill, Ambien, that contained the drug, zolpiderm.  During its use among the public, it was discovered that, for women, the level of the drug is 45 per cent higher the next day and this circumstance can result in car accidents.  This discovery led to a change in dosage recommended for women, to be reduced by half.

The gender imbalance in medical trials is clearly putting women at risk.  It also increases the likelihood that any drug will not work effectively or as intended when taken by women.   It is suggested that a women should always ask their physician whether any newly prescribed medication has been tested on women. However, even this question may be problematic because your physician may not have the answer to this question and also, what are a woman’s options if the suggested medication is the only, or most effective treatment for your condition?

The practice of male-centric medical trials needs to stop. An obvious way to affect a change is to legislate a minimum gender requirement for such research.  Even the exclusion of pregnant women from medical studies makes little sense since most pregnant women take various medications and it would be prudent to monitor for adverse affects during a controlled study.  The inclusion of men and women in medical and drug tests is surely also of benefit to pharmaceutical companies who will see fewer drugs rejected after being introduced in clinical trials or the marketplace.

Sources:

http://www.cbc.ca/news/health/sport-exercise-menstrual-cycle-1.3618140

http://bjsm.bmj.com/content/early/2016/05/17/bjsports-2016-096279

http://www.cbc.ca/news/technology/mouse-sex-studies-1.3545486

http://www.cbc.ca/radio/thecurrent/the-current-for-april-20-2016-1.3544290/of-mice-and-women-scientists-push-to-fix-gender-gap-in-lab-rats-for-research-1.3544451