New year: Two new drugs, two recently discontinued old drugs, and some miscellaneous medical rumors.
The first new drug is dabigatran, brand name Pradaxa. It’s an oral anticoagulant, a blood thinner that can be taken by mouth. It treats atrial fibrillation, a common heart rhythm abnormality that predisposes patients to strokes. Most atrial fibrillation patients take warfarin (brand name Coumadin) for this purpose.
Dabigatran prevents strokes as well as, or better than, warfarin, with about the same risk of unwanted bleeding. And it doesn’t require blood test monitoring. Warfarin patients must have blood drawn at least every month and more often when starting the medicine, changing the dose, sick, changing other medicines, etc. So dabigatran can be a boon for people who have trouble maintaining correct warfarin levels or trouble complying with the recommended testing.
Alas, dabigatran is no panacea. It must be taken every 12 hours rather than once daily for warfarin. It’s expensive, costing twice as much as warfarin even factoring in the required blood tests. Warfarin can be reversed with the injection of vitamin K, but there is no antidote if a patient develops excessive bleeding on dabigatran. Patients with serious bleeding on dabigatran need transfusion of fresh frozen plasma. Also, dabigatran is sensitive to moisture and must be used within 30 days of when the bottle is opened.
Another new drug approved in the past year is denosumab (brand name Prolia), an injection for the treatment of osteoporosis in postmenopausal women. It’s a monoclonal antibody: an actual specific human antibody produced in the laboratory. It’s given as an injection every six months delivered in the doctor’s office.
Our bones are always remodeling: old bone is reabsorbed and new bone formed. After menopause, bone breakdown often exceeds new bone production, leading to the bone thinning and structural changes of osteoporosis. Denusomab binds to a chemical called RANK ligand, a substance involved in bone breakdown. Denusomab slows both bone breakdown and overall bone remodeling.
In the three-year study leading to the drug’s approval, women taking denusomab had fewer fractures and higher bone density than controls. The medication is approved in special situations, such as women who have failed other osteoporosis treatments, or who have been unable to tolerate other medications.
Because the drug is new, the incidence of serious side effects remains unknown. Scientists don’t yet know whether denusomab will cause the same serious problems over time that were discovered in other osteoporosis drugs. These problems include osteonecrosis of the jaw, atypical thighbone fractures, or delayed healing of fractures. Known side effects include back, muscle, and bone pain, elevated cholesterol, and bladder infections. Because denusomab’s target, the RANK ligand, is also involved in the immune process, women taking Prolia have an increased risk of infection.
Propoxyphene (brand names Darvon, Darvocet) has been discontinued. It’s a weak pain reliever, no more effective than acetaminophen. It can cause abnormal heart rhythms, even in patients without known heart disease. Regular users of propoxyphene should taper off the drug to avoid withdrawal, rather than stopping cold turkey.
Abbott laboratories withdrew its popular weight loss drug Meridia from the market several months ago. The FDA recommended discontinuing Meridia because its modest effects for weight loss were not worth its increased risk of heart disease.
Super Glue, Ear Wax
The website that I used to research the above turned out to have a section that I hadn’t noticed before, called “Truth vs. Rumor.” It looks at the evidence supporting various medical rumors. I thought I’d share some knowledge gained from browsing that information.
Can superglue be used to repair skin wounds? I learned that the cyanoacrylate chemical used in household super glue is similar to, chemically different from the chemicals used in medical tissue glue. It’s probably safe to use household superglue for tiny wounds like cracked fingertips or paper cuts. Don’t use super glue on chronic wounds or larger wounds that require closure. Medical adhesives degrade more slowly than household superglue, lasting longer and causing less toxicity.
Can sodium docussate, an over-the-counter stool softener, help soften earwax? There aren’t any studies that show superiority of any one of various substances that have been tried to soften ear wax: commercial wax softeners, hydrogen peroxide, sodium bicarbonate, olive oil, or sodium docussate. But it’s safe and painless, so go ahead and try if desired.