Posts Tagged ‘osteoclasts’
We now have a third anabolic medication to build new bone. Evenity is really different from the other anabolics, Forteo (teriparatide) and Tymlos (abaloparatide). Forteo and Tymlos are daily shots based on the human hormones PTH and PTHrP. Evenity is an antibody to the human hormone sclerostin.
Sclerostin controls bone formation by telling osteoblasts to stop making new bone, and telling osteoclasts to gobble up old bone. This results in stable bone turnover remodeling (until menopause decreases control over the osteoclasts and they go wild). Evenity suppresses sclerostin.
Evenity markedly increases new bone matrix formation within the first month.However, the ability of Evenity to increase new bone formation diminishes month by month until it is mostly gone by one year. Therefore, it has been approved for use for only one year at a time. Like Forteo and Tymlos, Evenity must be followed by an antiresorptive to preserve the increase in bone.
Evenity also suppresses bone resorption by the second month. This is a less dramatic action, but it continues at the same level to the end of the year. The net result is a significant increase in bone matrix by the end of the year, in the same general order of magnitude as Forteo and Tymlos.
Evenity is a monthly shot into the subcutaneous fat on the back of both arms by a healthcare professional.
There is a possibility that Evenity may increase cardiac events in persons who have had a recent stroke or heart attack. This was found in only one of the 3 clinical trials of Evenity.
Preauthorization is required for insurance to cover Evenity. Most insurances will probably cover it within the first 3-12 months. More next time.
Jay Ginther, MD
Our goal is NO NEW FRACTURES. Therefore, Treat to Target means a FRAX score of <20% for “major osteoporotic” and <3% for hip fracture. Alternately, T-score of better than -1.5 if there are any fractures.
Antiresorptives do not substantially increase bone mass or BMD. While a 3-5% BMD improvement can be seen when a long term deficiency in calcium absorption is corrected, the function of an antiresorptive is to maintain current bone mass.
If you want to substantially increase bone mass, you must use an anabolic medication. We now have 2. Forteo (teriparatide) has been available for 15 years. Tymlos (abaloparatide) was approved late last spring, but has only achieved good coverage by a majority of insurance companies in the last month.
Both can be given for up to 24 months. Both must be followed by an antiresorptive to avoid loss of gains. Both will show continued improvement in BMD for up to 3 years after switching to an antiresorptive because calcium takes up to 3 years to fully accumulate in new bone matrix formed by an anabolic.
Both should NOT be given to anyone with open growth plates, Paget’s, radiation to bone, cancers which have or could spread to bone, elevated bone specific alkaline phosphatase other than from fracture healing, or pregnant or nursing women.
Tymlos is approved for postmenopausal women only. It does not stimulate bone turnover significantly and therefore shows faster BMD increase initially in the hip. It has not been tested for use after antiresorptives.
Forteo is approved for men and women with osteoporosis which is “age-related”, or from steroid use, or from idiopathic hypogonadism. Forteo significantly increases both osteoblast and osteoclast activity, thereby stimulating bone turnover, which is often suppressed after long-term antiresorptives. Forteo is the default treatment for ONJ and AFF.
If you are dealing with vertebral fractures on VFA, or really low BMD on DXA, or with multiple fragility fractures, you need an ANABOLIC FIRST, to decrease fracture risk. Then follow with antiresorptives to maintain a low enough fracture risk.
Remember, even these medications will fail without proper nutrition.
jay Ginther, MD
Smoking is a major risk factor for fractures. Smoking suppresses the osteoblasts (the cells that make new bone). The osteoclasts (cells that eat away bone) then can easily outdo the osteoblasts, and you lose bone mass. Lower bone mass = more fractures.
Stopping smoking altogether is the best for your bone health. That is really tough to do. E-cigarettes have not proven less harmful to bone. Nicotine patches help only if they eventually lead to less nicotine intake than with smoking.
The damage smoking does to your bones (and lungs, and heart) is dose related. Therefore, cutting way down is almost as good as quitting, and often much easier to do.
Especially if you are trying to heal a fracture, stopping smoking, even for a few weeks, is really important. 1 ppd smokers are 5 to 10 times as likely to not heal a fracture. The same is true for infection rate after surgery.
Steroid Inhalers also suppress osteoblasts and bone formation. Unfortunately many cannot get off their steroid inhalers, even after they quit smoking. Major bummer.
Take Control Naturally of your bone health. Stop Smoking. Or at least cut way back.
Jay Ginther, MD
Patients, Primary Care Docs, and Orthopedic Surgeons all worry about bone surgery while on Osteoporosis Medications. They also worry about Atypical Fractures of the Femur (AFF). There is one medication that actually helps bone healing and is routinely used to treat AFF. That is the Anabolic, Forteo.
Atypical Fracture of the Femur is quite rare. AFF has become less rare since we started treating osteoporosis with Antiresorptive Osteoporosis Medications. Typical Femur Fractures are still about 100 times as common – and we can prevent over half of those with Antiresorptive Osteoporosis Medications.
AFF is a Stress Fracture, usually just below the hip, that starts on the lateral side of the Femur. It is a small crack, which can gradually spread across the bone.
The best treatment for a stress fracture is stimulating the cells that make new bone (OsteoBlasts) and also stimulating the cells that gobble up bone (OsteoClasts). This increases bone turnover, which is needed for healing a fracture, especially a stress fracture.
Forteo is the only Anabolic we currently have in the USA. Forteo is routinely used to treat AFF before, as well as after, the fracture. It is also used to treat other stress fractures such as metatarsals in the feet and “shin splints” in the proximal shaft of tibia.
Forteo is also commonly used to enhance healing in osteoporotic patients in spine fusions and in total joint replacement.
Jay Ginther, MD