Back, hip pain not linked finasteride
Dear Dr. Roach: I am an 82-year-old male. I have been taking finasteride and tamsulosin for two years now for enlarged prostate. Since December 2021, I started having lower back pain and hip pain when walking. Aside from both high blood pressure and cholesterol, I am in good shape. My question is: Could the back and hip pain be the result of taking finasteride? According to the information on this drug’s side effects, it can cause prostate cancer with lower back and hip pain. My urologist said that it is perfectly safe to take. What is your opinion?
Answer: Finasteride blocks the enzyme that converts regular testosterone into dihydrotestosterone. DHT is one of the major causes of prostate enlargement and hair loss, so finasteride is an effective treatment for both conditions. No medicine, unfortunately, is “perfectly safe,” but the most common serious side effects of finasteride are sexual troubles, such as erectile dysfunction or loss of libido, occurring in about 1.5% of men who take it.
Finasteride, because of its ability to shrink the prostate, was studied to see if it reduced the risk of prostate cancer. One study was stopped early because there was about a 25% relative reduction in the risk of prostate cancer (from 15% of men taking no active drug versus 10.5% in men on finasteride). However, there was a small increase in the risk of aggressive prostate cancer (from 3% in the group taking no active medicine to 3.5% in the finasteride group). Subsequent research, which I think your urologist is referring to, showed that at least some of the apparent difference was caused by the medicine shrinking the prostate and making it easier to spot the cancer. After 25 years of follow-up, men who took finasteride had a 25% reduced risk of dying from prostate cancer. I do not think that finasteride increases the risk of aggressive prostate cancer.
By far, the biggest cause of lower back and hip pain in men in their 80s is arthritis. Advanced prostate cancer can certainly cause bone pain, but I believe your urologist must have evaluated this possibility. Your regular doctor should be able to help discover why you are having this pain. An X-ray may be necessary.