Combined contraceptive patches may be less effective in which group of women?

• A. Women under 120 pounds
• B. Women over 200 pounds
• C. Women with a family history of blood clots
• D. Women taking other medications

Answer: (B)

The effectiveness of combined contraceptive patches may be reduced in women over 200 pounds due to pharmacokinetic factors. These patches are designed to release hormones through the skin into the bloodstream, and the amount of hormone absorption can vary based on body weight and fat composition. In women with a higher body weight, there may be a greater volume of distribution for the hormones, which can lead to lower serum hormone levels. This reduced hormone level can diminish the contraceptive efficacy of the patch, making it less reliable for women in this weight category.

The other groups mentioned, while they may have specific considerations, do not directly impact the pharmacokinetics of hormone absorption through the patch in the same manner as excessive body weight does. Women under 120 pounds may actually experience adequate hormone absorption, and those with a family history of blood clots would have concerns regarding thrombosis risk but not necessarily concerning the efficacy of the patch itself. Women taking other medications may affect the metabolism of contraceptive hormones, but this is not a broad effectiveness issue in the same way body weight influences absorption and distribution.