Sunday, December 27, 2009

Teriparatide ( Recombinant human PTH ) effectiveness in Osteoporosis treatment


Teriparatide, Recombinant human PTH (rh PTH [1-34]), which has an identical sequence to the 34 N-terminal amino acids of human PTH.

Osteoporosis is defined by the World Health Organization as a T-score of -2.5. T-score is the value compared to control subjects who are at their peak bone mineral density, while Z-score reflects a value compared to patients matched for age and sex.
Osteoporosis is a condition in which bone mass is low and microarchitectural deterioration of bone tissue occurs, leading to bone fragility and an increased risk of fracture.


Gaols of Osteoporosis therapy is to 
- prevent fragility fractures and future fractures in post menopausal and elderly
- stabilise/increase bone mass 
- relieve symptoms of fractures and/or skeletal deformities
- improvemobility and functional stability



Goal of osteoporosis management: prevention of the first fracture:
 - Women who have 1 vertebral fracture have an 11-fold increased risk of ever having another vertebral fracture.
 -Women with 1or more pre-existing vertebral fractures have an 5.1-fold increased risk of another vertebral fracture within the next year.


Therapeutic options:
A. Inhibition of bone resorption = antiresorptips:
1. Bisphosphonates
Alendronate
Risedronate
Ibandronate
Zoledronate
2. Calcitonin
3. Estrogen+Progestins (HRT)
4. SERMs (Selective estrogen receptor modlators
- Raloxifen
B. Stimulators of bone formation = anabolic
1. Fluoride
2. Parathyroid Hormone  rhPTH (134):
- Teriparatide
C. Mixed mechanism of action:
1. Active vit D metbolites
2. Strontium Ranilate
D. Recommended for all women at risk of Osteoporosis:
- Ca and Vit D

Effect of Teriparatide on Structural Indices : Quantitative analysis-Significant changes in -
Trabecular bone volume
- Structure model index
Connectivity density
Cortical thickness

Patient treated with teriparatide 20µg sc/d

Female, age 65
Duration of therapy:  637 days (approx 21 months)

BMD Change:
  ÞLumbar Spine: +7.4%  (group mean = 9.7 ± 7.4%)
  ÞTotal Hip:          +5.2%  (group mean = 2.6 ± 4.9%)