Dear Dr. Roach: Approximately five years ago, I was diagnosed with an aggressive prostate cancer. My urologist referred me for radiation therapy, to be followed by Lupron every six months for two years. The shots caused low libido and hot flashes, which exacerbated my rosacea. At the time, I asked my urologist if I could start on testosterone. He replied that it might cause a recurrence of the cancer. About two years ago, a new urologist prescribed testosterone replacement, and the hot flashes and libido problem have decreased.
Did the testosterone replacement possibly cause the improvement in my libido and skin condition? — D.T.
Answer: The use of testosterone replacement in prostate cancer survivors is controversial. Prostate cancer growth is generally encouraged by testosterone. The role of leuprolide (Lupron) is to reduce testosterone levels to nearly zero. This removes stimulus to growth of the cancer cells. Testosterone treatment makes no sense for a man who is receiving active treatment with medications like Lupron.
In men who have had successful treatment, whether by surgery or radiation, testosterone replacement therapy can be considered. After surgery, this means that the PSA level is zero, meaning no detectable prostate tissue. Several small studies have suggested that testosterone replacement therapy is low risk in this situation. A careful discussion of the potential risks and benefits is necessary before prescribing this medication.
Very low testosterone levels almost always cause a loss of libido, and when the loss occurs quickly, such as with medication treatment or surgery, hot flashes sometimes occur. Hot flashes in men or women can exacerbate rosacea, so I think it’s very likely that the loss of testosterone with your Lupron therapy caused your symptoms, and that the treatment with testosterone replacement effectively treated these symptoms.
DEAR DR. ROACH: Could taking ivermectin as an alternative to vaccination for COVID cause damage to the retina? — K.D.
ANSWER: When used at appropriate doses, ivermectin is a safe and effective medication for certain parasitic infections. Ivermectin has not been shown to be effective for COVID-19, and should not be thought of as an alternative to vaccination, since it does not prevent infection. It also should not be thought of as an alternative to effective treatments, such as some monoclonal antibodies or Paxlovid. There continue to be clinical trials testing ivermectin, but the studies published (excluding those that have been retracted) to date have not shown significant benefit to ivermectin. There were studies that showed that at high doses, ivermectin stops viral replication, but those levels cannot be achieved in the blood.
Some people have used veterinary products that were never intended to be used on humans. Although I found reports of retinal damage using ivermectin in several animal species, I did not find reports in humans. Reported side effects included nausea, vomiting, abdominal pain, diarrhea, headache, blurred vision, dizziness, fast heart rate, low blood pressure, visual hallucinations, confusion, loss of coordination and balance, and seizures.
