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| Primary information |
|---|
| ID | 12457 |
| Therapeutic ID | Th1324 |
| Protein Name | Parathyroid hormone |
| Sequence | >Th1324_Parathyroid_hormone
SVSEIQLMHNLGKHLNSMERVEWLRKKLQDVHNFVALGAPLAPRDAGSQRPRKKEDNVLVESHEKSLGEADKADVNVLTKAKSQ
|
| Molecular Weight | 9420 |
| Chemical Formula | C408H674N126O126S2 |
| Isoelectric Point | NA |
| Hydrophobicity | NA |
| Melting point | NA |
| Half-life | 1.5 hours. |
| Description | Parathyroid hormone (PTH) is a single-chain polypeptide composed of 84 amino acids. Available as Preotact, it is an identical form of human recombinant hormome which produced as a fusion protein undergoeing post-translational processing involving the cleavage of the OmpA leader sequence, leaving the mature protein as a single-chain 84 amino-acids polypeptide (9.4 kDa). Preotact is used in the treatment of osteoporosis in postmenopausal women at high risk of osteoporotic fractures and is marketed in Europe by Nycomed. Preos is a registered trade mark owned by NPS Pharmaceuticals, Inc. The name Preos and the New Drug Application is pending approval by the U.S. Food and Drug Administration (FDA). |
| Indication/Disease | For use/treatment in osteoporosis. |
| Pharmacodynamics | Parathyroid hormone is responsible for the fine regulation of serum calcium concentration on a minute-to-minute basis. This is achieved by the acute effects of the hormone on calcium resorption in bone and calcium reabsorption in the kidney. The phosphate mobilized from bone is excreted into the urine by means of the hormone's influence on renal phosphate handling. Parathyroid hormone also stimulates calcium absorption in the intestine, this being mediated indirectly by 1,25-dihydroxyvitamin D. Thus, a hypocalcemic stimulus of parathyroid hormone secretion results in an increased influx of calcium from three sources (bone, kidney, and intestine), resulting in a normalization of the serum calcium concentration without change in the serum phosphate concentration. |
| Mechanism of Action | The biological actions of rhPTH are mediated through binding to at least two distinct high- affinity cell-surface receptors specific for the N-terminal and C-terminal regions of the molecule, both of which are required for normal bone metabolism. The N-terminal portion of the molecule is primarily responsible for the bone building effects of parathyroid hormone. The C-terminal portion of the molecule has antiresorptive activity and is necessary for normal regulation of N-terminal fragment activity. |
| Toxicity | NA |
| Metabolism | PTH is primarily metabolised in the liver with lesser contributions by the kidney. Amino terminal fragments are metabolised in the liver while carboxyl terminal groups travel to the kidney for metabolism where they are also thought to have a role in regulation of PTH. Only about 30% of circulating hormone is present as the unfragmented form. |
| Absorption | The absolute bioavailability after subcutaneous administration in the abdomen is 55% for doses of 100 micrograms. |
| The volume of distribution at steady-state following intravenous administration is approximately 5.4 liters with an interpatient variability of about 40%. |
| Clearance | NA |
| Categories | Systemic Hormonal Preparations, Excl. Sex Hormones and Insulins |
| Patents Number | NA |
| Date of Issue | NA |
| Date of Expiry | NA |
| Drug Interaction | NA |
| Target | Parathyroid hormone/parathyroid hormone-related peptide receptor,Parathyroid hormone 2 receptor |
| Brand Name | Preotact |
| Company | Nps Pharma Holdings Limited |
| Brand Description | Nps Pharma Holdings Limited |
| Prescribed For | Subcutaneous |
| Chemical Name | 100 µg |
| Formulation | NA |
| Physical Appearance | The most common side effects reported with Pergoveris (seen in more than 1 patient in 10) are headache, ovarian cysts and injection site reactions (e.g. pain, itching, redness, bruising, swelling or irritation at the site of injection). Treatment can cause overstimulation of the ovaries (known as ovarian hyperstimulation syndrome, OHSS), which can lead to serious medical problems. Mild or moderate OHSS is common, while severe OHSS is uncommon. |
| Route of Administration | Preotact is a medicine that contains the active substance parathyroid hormone. It is available as a powder and solvent, contained within a cartridge, to be made up into a solution for injection using a special injection pen. It is also available as a pre-filled pen incorporating the cartridge containing the powder and solvent Each cartridge contains 14 doses. |
| Recommended Dosage | Preotact is used for the treatment of osteoporosis (a disease that makes bones fragile) in postmenopausal women who are at high risk of fractures. Preotact has been shown to significantly reduce vertebral (spine) fractures, but not hip fractures. |
| Contraindication | NA |
| Side Effects | NA |
| Useful Link 1 | Link |
| Useful Link 2 | Link |
| Remarks | NA |