Welcome back. Today we have news about a drug that doesn’t do the bad thing it was expected to do, another drug that does a bad thing that wasn’t expected to do and a third cancer drug that is used too often. Read on and, please, when offered a medicine, always ask your doctor: what happens if I do nothing? What happens if I wait? What are the risks? Are there non-drug alternatives? What’s my best possible outcome and my worst possible outcome?
Be well.
Overactive Bladder
Myrbetriq (generic name mirabegron), a new overactive bladder drug, was suspected of causing arrhythmia during trial periods. In a follow-up study there seems to be no such risk.
During drug trials it was noted that the method of action of the drug logically would lead to arrhythmia and other cardiovascular events. (Why? Mirabegron is the first β3-adrenoceptor agonist. β-3 agonist medications have limited adverse effects compared with antimuscarinic agents — the drug used before mirabegron was approved. “However, β3-adrenoreceptors are associated with increases in contractile force and reductions in inotropic effects, actions which raise concerns of cardiovascular (CV) adverse effects. These adverse effects have been reinforced by trials, finding a small increase in heart rate, blood pressure, and QTc intervals.” Aren’t you glad you learned that?)
In short, there is good reason to predict that Myretriq should cause arrhythmias, something women are more prone to as they age (about the same time they might have an overactive bladder issue from other reasons), but in the real world that doesn’t seem to be happening.
Another example of why medical beliefs, even logical ones, need to be tested in real, human clinical trials.
- Association of Mirabegron With the Risk of Arrhythmia in Adult Patients 66 Years or Older—A Population-Based Cohort Study – JAMA, July 15, 2019
- No Real-World CV Risk for Newer Overactive Bladder Drug – MedPage Today, July 16, 2019
Thyroid Cancer
If you have low-risk papillary thyroid cancer, current guidelines state you don’t need to have radioactive iodine treatment. In a recent study, about 25% of such patients got RAI anyway.
Is it better to be safe than sorry and treat the thyroid cancer with RAI even though it’s low-risk cancer? Not in this case. Too often it leads to much more aggressive care — in the same study it was found that “patients treated with RAI underwent total thyroidectomy and more extensive lymphadenectomy significantly more often when compared with patients who did not get RAI,” from MedPage.
The MedPage article also reported on a separate study about patients’ perceptions of doctor recommendations about RAI and their satisfaction after the fact. The study found that many patients did not feel they had an option on RAI — their doctor recommended it that strongly. And those who felt most pushed into RAI were most often the ones dissatisfied with their outcome.
The takeaway? With thyroid cancer and any other diagnosis, you have to live with the outcomes. If your doctor doesn’t offer “shared decision making” then push your caretaker into the conversation you need:
- Overtreatment of Low-Risk Thyroid Cancer – MedPage Today, July 16, 2019
- The overuse of radioactive iodine in low-risk papillary thyroid cancer patients – Surgical Oncology, June 29, 2019
- Patient-Perceived Lack of Choice in Receipt of Radioactive Iodine for Treatment of Differentiated Thyroid Cancer – Journal of Clinical Oncology, July 2019
Prostate Cancer and ADT – Androgen Deprivation Therapy
A large retrospective study of more than 150,000 people diagnosed with prostate cancer indicated that those treated with ADT (androgen deprivation therapy) were more likely to be diagnosed with either dementia or Alzheimer’s during the next ten years. Prostate cancer has a very high 5-year survival rate, so it’s recommended that you carefully discuss your options with your healthcare provider before moving ahead with ADT.
