The Evolution of Gender-Based Medicine
For decades, medical research was performed almost exclusively on men. In some cases, the reason was to protect women who may be pregnant during the study, and in other cases it was women’s menstrual cycles that prevented them from participating, because hormonal and chemical changes would prevent correct assessment of the results. This also led to a neglect in studying the effects of medicine on women during their menstrual cycle. Even nowadays, two thirds of the illnesses that affect both genders are still studied on male subjects, and most experimental drugs are tested on men.
The emergence of gender-based medicine occurred during the 1970s, but only during the 90s were these issues discussed in a wider forum. When it came to conditions that were considered “women only”, such as breast cancer and osteoporosis, men were not included as test subjects. The result was that it became much harder to diagnose these conditions in men, despite the fact that they do appear in them, as well as providing appropriate treatment for each gender.
At this time, medical science is finally aware of the different effects medication has on men and women. In a 2001 study, it was found that 11% of cases where women were hospitalized resulted due to incorrect medication, while in another study it was found that women seem to suffer more from side effects compared to men by a ratio of 50-70 percent.
Why Do Medicines Affect Men and Women Differently
There are several reasons for why men and women have different reactions to certain types of medications:
1. Physical size and anatomy
Even though women are often physically smaller than men, they receive the same dosage. This means that they have a higher concentration of the medicine in their body, which could explain the differences in how the body reacts to it. At the same time, anatomical differences between genders can lead to increased sensitivity to certain types of medication in women.
2. Difference in how the body processes medication
Our kidneys play a vital role in clearing toxins and excess medication from the body. In older women, however, there is a decrease in kidney functions, which some studies suggest is considerably higher than in men. This means that some women end up being exposed to higher concentrations of the active ingredients in medication. Additionally, enzymes in the stomach lining and the liver, which are part of a system called “P450” that also helps remove excess medicine in the body, behave differently in men and women.
3. Stomach acidity levels
The digestive system in men and women works differently, so medication taken orally can affect each gender differently. In women, stomach acidity is lower than in men, leading to a slower emptying process. This means that the active ingredients in the medicine absorb in the stomach for longer periods, which affects women more than men.
Medication that Reacts Differently in Men and Women
Since the subject of the different effects medication has on different genders is still being studied, the following list cannot be considered as comprehensive or complete, since more types of medication are likely to be added to it in the future. If you’re taking medication that appears on this list, are planning on changing your medication, or are experiencing unusual side effects, consult with your physician.
Serotonin is a known antidepressant, but women naturally produce less of it than men. The result is that serotonin-based antidepressants are far more effective in women than in men. Men, however, seem to react better to imipramine, a tricyclic antidepressant.
Valium is used to reduce anxiety, and is often prescribed in the same dosage for both men and women, despite the fact that women process it faster than men, reducing its efficacy. The reason is that the high level of estrogen in women affects an enzyme called A43, which breaks down the Valium in the body. Since the breakdown is greater, women may require higher doses of Valium than men.
3. Zolpidem-based insomnia drugs
Many women who were taking zolpidem containing sleeping pills suffered from side effects such as night terrors, difficulty in waking up, headaches, etc. In 2013, following a study into the matter, the U.S. FDA instructed women to reduce their dosage by half. The reason is that women seemed to process the drug at a slower rate, thus increasing its efficacy. The side effects of zolpidem on women also increased the risk of car accidents.
4. Statins-based cholesterol-lowering drugs
Statins based cholesterol medication is commonly used as a treatment for high cholesterol and as a preventative measure for coronary diseases, despite the fact that these drugs were only tested on males. More recent studies found that while these drugs lower the risk of heart attacks in men, their effects on women are significantly lower, even compared to men with a history of heart problems.
5. Losartan-based blood pressure medication
While the increased activity of the A43 enzyme lowers the efficacy of certain medications in women, in some cases it can do the opposite and cause an overdose. The effects of losartan in women who take it for high blood pressure may lead to much stronger effects than in men who take the same dosage, thus causing their blood pressure to drop dangerously low.
There are women who take this NSAID on a daily basis as a form of prevention for coronary diseases, yet all the studies that recommended this practice were performed on men. In fact, aspirin does not protect women’s cardiovascular system in the same way it does for men, and doctors often recommend a considerably higher dosage to women who have been through a coronary event. However, in recent studies, it was found that aspirin does more to protect women from stroke compared to men.
Though there are very few cases of people who have woken up during surgery, or that report that they heard what was happening in the operating room, the number of women who reported these experiences is three times higher than men. Researchers have found that each gender reacts differently to the anesthetics because of the distribution of fat, which differs between males and females. For this reason, anesthetics that are fat soluble, such as Propofol, are more effective on men, while water soluble anesthetics are more effective on women.
There are known differences in pain sensitivity and threshold between men and women, very few studies have been performed on the efficacy of painkillers for each gender. This is troubling because it is directly related to their efficacy and risk of addiction. In one of the few studies on this topic, it was found that the difference between male and female metabolism, women tend to enjoy a more powerful effect from opioid painkillers. This means that women need a dosage that is 30-40% smaller than men. Men, on the other hand, respond better to Nonsteroidal anti-inflammatory drugs (NSAID).
9. Epilepsy medicine
The hormonal changes women experience during their menstrual cycle has a significant effect on the efficacy of many types of medication. For example, progesterone may speed up the system that cleanses drugs from the body. In some women who suffer from epilepsy, this hormone may lead to a multitude of seizures prior to menstruation. Some women don’t make the connection between the increase in the frequency of attacks and their menstrual cycle, and many doctors won’t even ask them about it, despite the fact that this can easily be resolved by changing medication or dosage.
In conclusion, as mentioned in the beginning of this article, the most important thing is to be aware and vigilant of whatever type of medication you take. Avoid taking anything before consulting with a doctor, and don’t be afraid to ask if the dosage is right for your gender, age, weight, and medical history.