The last thing anyone should want is gender equality when drugs are prescribed. Each year more studies add to our knowledge that men and women’s bodies process drugs differently, for a variety of reasons. Traditionally drugs were only tested on men. In the past couple of decades women have been represented in tests, but often in smaller numbers and certainly not during important health stages such as during pregnancy. Most of the drugs that were tested before women were included in the studies remain unstudied for women.
Women are 50% to 75% more likely than men to experience an adverse drug reaction, according to a study published in American Family Physician. Women also need to be more alert to drug interactions because more women take prescription medicine than men. Consider this: millions of perfectly healthy women take very strong prescription drugs daily: birth control pills. The Pill becomes such a part of their daily life that interactions with other drugs — used for a specific, short illness — might be overlooked. For example, antibiotics lower the efficacy rate of most oral contraceptives.
Most dosing guidelines are not yet tailored to women. A “standard” prescription, developed and tested on men, may well be harmful to a woman with significantly lower weight, higher body fat (a factor in metabolizing some drugs and vitamins) and smaller organs. Women tend to have lower compliance than men, perhaps because the side effects are magnified?
Women have “slower gastrointestinal motility” meaning their stomachs retain food longer. The time between eating and taking a medicine that should be taken on an empty stomach is longer for women (but we don’t know how much longer).
Women’s periods, and the stage of the menstrual cycle, changes how a drug is accepted in the body. Daily drugs like SSRIs (Selective serotonin reuptake inhibitors like Prozac and Zoloft, etc) may seem more powerful at one stage of a cycle and less in another. That makes adjusting dosages very difficult.
Here are some of the drugs that have been flagged as having different outcomes in women vs. men (from Society for Women’s Health Research):
- Diazepam (Valium) – impair the control of voluntary movements more in women than men.
- SSRIs – Selective serotonin reuptake inhibitors (Prozac, Paxil, Lexipro, Zoloft, etc) – seem to stay in the blood stream at higher concentrations for longer periods of time for women vs. men. Doctors don’t know what this means in terms of efficacy.
- Acetaminophen (Tylenol) is deactived 50% more frequently in women taking oral contraceptives as compared to control groups.
- Antibiotics lower the efficacy of many oral contraceptives.
- Erythromycin (antibiotic) and Verapamil (for high blood pressure) are more effective in women.
- Digoxin (made from digitalis, for heart failure) – women have a higher mortality rate than men when using this drug. via MedLine/NIH
Interestingly, women are more likely to have a regular doctor than men, and women are 48% more likely to take an abusable prescription drug.
When accepting a prescription from your health care provider, always discuss what the side effects might be and what dosing adjustments might be needed. Don’t assume that because the doctor prescribed 20mg of a drug that 20mg must be the correct amount for you. Report back to your doctor so that your health care provider can give you the prescription that is best for you and not for a statistical average.