Dear Dr. Roach: My son and his new wife went on a dream honeymoon that has since turned into a nightmare. They went to Costa Rica and of course were bitten by mosquitoes. Upon returning home, they were told about the Zika virus. One person told them to wait six months before trying to have a baby; another source said to wait two years. They are in their mid-30s and want to have a baby. What do you know about this scary virus?
Zika virus is transmitted by mosquitos and is present in many areas of the Americas, Caribbean and Pacific. There has been an ongoing outbreak over the past few years. Zika is related to yellow fever, dengue and West Nile virus. One major concern about Zika is that it can cause neurological complications, sometimes severe, in babies born to women who were infected during pregnancy. Also, Zika may temporarily affect fertility in infected men. Zika can be transmitted sexually.
Couples who are planning pregnancy should avoid areas where Zika transmission occurs (see nc.cdc.gov/travel/page/zika-information). For couples who have been exposed or who might have been infected, the most conservative recommendation I have read is six months. This is based on a finding of Zika RNA in men up to 188 days after having symptoms of Zika, even though no sexually transmitted cases have been reported more than six weeks after the man had symptoms of Zika (men and women may also transmit Zika after an illness without recognized symptoms). Given how severe the infection can be to the developing fetus, I think six months is the right amount of time, but two years is unnecessary.
Dear Dr. Roach: I am a postmenopausal woman with osteoporosis (my T-score is -3.2) in my spine. I used alendronate, but stopped because it caused bone pain. I haven’t been on any medication for a few months now, but I have started walking 40 minutes every day and I use weights. Also, I monitor my calcium and vitamin D carefully. My last bloodwork all came back good. My doctor would like me to try Tymlos. I can’t find much information about it except that it hasn’t been out long and may cause osteosarcoma. Do you know what the chance of this might be? A similar drug, Forteo, is not covered by my insurance, even though it has been around longer.
Abaloparatide (Tymlos) is an analog of parathyroid hormone. It works against osteoporosis by stimulating bone growth. This is different from the mechanism of alendronate (Fosamax) and related drugs; those work by preventing bone reabsorption.
Teriparatide (Forteo) indeed works the same way as Tymlos. During drug testing, teriparatide was found to increase the risk of a type of bone cancer, osteogenic sarcoma, in rats. Because of this, the Food and Drug Administration required a black-box warning, the agency’s highest degree of caution. However, a study on women who have taken Forteo showed no cases of osteogenic sarcoma in the first seven years of the study, and only a handful of cases have ever been reported in people taking Forteo. In fact, the number of cases reported is less than would have been expected if there were no association between the drug and the cancer. It appears so far that Forteo does not increase risk for bone cancer, and there’s no reason to expect that Tymlos will do so.
Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu.