It seems quite intuitive to think that drugs do not affect men and women equally, but many of the studies that are carried out with drugs (before they are released on the market), are not carried out on women, arguing that menstrual cycles can affect the results of studies.

Same drugs but different effects according to sex

Another more concrete example is that of pregnant women. Pregnant women do not participate in trials of this type, for obvious reasons, but this leads to some long-term problems, such as not knowing the effects of such substances during the pregnancy period. Thus, a woman with a bipolar disorder , as has been well established, needs a higher dose of the drug Lamictal to control her depression during pregnancy.

The U.S. Food and Drug Administration (FDA) recalled 8 out of 10 drugs because they posed greater health risks to women than to men .

In addition, the probability of suffering side effects is in women between 50 and 75 percent higher than men.

Below, we mention some types of medication and the different effects they can have depending on the sex.

Painkillers

  • Opioid analgesics are more effective in women . It is believed to be a consequence of fluctuations in oestrogen , as these affect sensitivity to pain .
  • overdoses of painkillers are more frequent in men than in women.
  • Women find it more difficult to “unhook” from their consumption.
  • In the case of reaching a state of addiction, women are more likely to relapse , because during some periods of the menstrual cycle blood glucose levels drop, and these in turn are related to the capacity for self-control.

Antidepressants

  • Women respond better to SSRI antidepressants (selective serotonin reuptake inhibitors).
  • Men, on the other hand, seem to get more benefit from tricyclic antidepressants .
  • The fact that certain antidepressants have better effects on women is due to the fact that their blood has less ability to bind , so their hemoproteins absorb less foreign substances.
  • The female stomach is less acidic than the male stomach, this causes SSRIs to be absorbed, it seems, more quickly, thus accentuating their toxicity .

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  • Another important point is that the higher percentage of fat in women also increases their body’s ability to retain antidepressants for longer periods .

Hypnotics

  • Man more easily breaks down Zolpidem (a type of hypnotic) and other sleep inducers.
  • Women , on the other hand, retain more of these drugs in the liver, which can affect them to a greater extent throughout the day .

Anxiolytics

  • The fact that the woman has a less acidic stomach than the man may contribute to her feeling the effects of the anxiolytics more strongly , increasing the toxicity levels of the doses.
  • Because women filter drugs more slowly, should allow more time between doses , especially for benzodiazepine (one of the most common anti-anxiety drugs).
  • As with antidepressants, fat facilitates the retention of anxiolytics in the body for longer, increasing the risk of side effects and toxicity in lower doses .

Antipsychotics

  • Information on the effects of antipsychotics by gender has been based primarily on first-generation antipsychotics, such as haloperidol (a type of antipsychotic widely used in the late 20th century). These have been shown to be more effective in women than in men. Men need higher doses to get the same results .

Anticonvulsants

  • The liver enzyme CYP3A4 [1], which is especially active in women , makes these drugs less effective than in men .

Conclusion

Despite the lack of studies on this subject (in fact, these results are one of the few that exist), this is a marginalized but extremely important field of study , since, taking into account gender differences, drugs could be better adapted to each gender, avoiding unnecessary risks. Therefore, the FDA announced that it will intensify its efforts to take into account these types of differences in future clinical trials .

Author’s notes:

1] The enzyme CYP3A4 is responsible for metabolizing xenobiotic compounds in the body, or in other words, it processes compounds that do not occur naturally in the human body, such as most drugs.