St. Joseph’s Healthcare rheumatologist Dr. Rick Adachi is among the first physicians in Canada to prescribe a breakthrough medication, a natural bone-building hormone that doubles the normal rate of bone formation.
“It is important to understand that bone is not a hard and lifeless structure; it is, in fact, complex, living tissue. In osteoporosis, the bones become weakened as cortical bone gets thinner and the spaces in spongy bone get larger. Bone density is lost Ñ bones become thin and fragile, more likely to break,” says Dr. Adachi. “With our current therapies, we are able to maintain bone, but with this new therapy, Forteo, we are able to actually reconstitute, regenerate, bone.”
The remodeling of bone requires the coordinated activity of two types of cells: osteoclasts, that demineralize bone in their vicinity and osteoblasts, that secrete collagen and mineral to lay down new bone in their vicinity. It is the excessive activity of osteoclasts that produces osteoporosis in postmenopausal women and many men.Forteo is a synthetic form of parathyroid hormone (PTH) that is naturally found in the body. “The drug stimulates the osteoblasts to make new, better and more bone.”
Weakened bone caused by the degenerative bone disease often leads to fractures that can be life threatening. Statistics show a mortality rate of 15 – 20 per cent within six months of a hip fracture – a rate that rises with the older population. Dr. Adachi believes that preventing those fractures could theoretically prevent those deaths. Certainly many hospitalizations could be prevented.
Quality of life and the prevention of pain are also of extreme importance. “The patients that we see have very, very weak bones. And they’re continuing to fracture despite all the therapy. As they continue to fracture, they get debilitating pain. Forteo seems to prevent not only those fractures, but prevent the micro-fractures we’re not seeing on x-ray. And over time we see people who have been in pain for months and months say they don’t have the same amount of pain. And for the patient who’s fracturing that’s a big deal.”
“I’ve had patients who can’t sit up, can’t sit at the dinner table because of the pain. They need to use a walker or other assistive devices. But as the pain lessens, they can do things – get their life back.”
Forteo is given by a once a day subcutaneous injection. Patients who are prescribed the drug agree to be part of a Patient Care Program and a nurse comes to their home to teach them how to administer the drug to themselves. Patients are on the drug for 18 months and then return to other therapy.
Patients should be made aware that Forteo caused osteosarcomas in rats and that the clinical relevance of these findings is unknown. “I don’t view this as a real risk,” says Dr. Adachi. “In close to twenty years of patients with hyperparathyroidism the development of osteoscarcomas have never been detected. We do see osteosarcomas in patients who have had radiation or patients with Pagett’s Disease, but they are contra-indicated for treatment with Forteo.”
“I think that this is a very good drug. We’re seeing bone mass go up. It can increase by ten, eleven per cent with the PTH therapy. If you then add in Actonel or Fosamax or Evista, it goes up even further. We’re seeing an improvement in the structure of the bone and as result of that we may see a drop in the fracture rate and that is why I think this is very important. Forteo has the potential for reversing and potentially even curing patients who have osteoporosis.”