What is Teriparatide?

It is a artificially prepared Parathyroid hormone, rDNA origin.

Used to treat both men and post monepausal women, who are at a high risk of having fractures.

Common Brand Names

Common brand names under which the medicine is sold include, Forteo, Terifrec

Mechanism of Action?

Teriparatide is identical to a portion of PTH. Its intermittent use stimulates bone cells.

The complete PTH hormone has 84 amino acids. Teriparatide has 34 amino acids out of these 84.

Bone cells are chiefly of two types, osteoblasts and oseoclasts. Osteoblasts make newer bones while osteoclasts are involved in bone destruction.

Teriparatide stimulates the osteoblast more than osteoclasts and have a overall anabolic effect. Bone mass increases with its use.

Understanding PTH (Parathyroid hormone)

Our body has four parathyroid glands, located behind our thyroid in the neck. These are four tiny glands, two on each side, controlling the metabolism of calcium in the body.

They secrete a hormone, called, parathyroid hormone, in the blood.

When calcium levels in the blood become low, parathyroid glands secrete more PTH. PTH promotes release of calcium in the blood, hence raising up the calcium levels.

They also act on our kidneys to reduce the loss of calcium via urine.

Effect of PTH on blood calcium?

It increases blood calcium.

Calcium release from the bones increases,
Its absorption by the intestines increases and
Excretion via the kidneys decreases.

Effect of PTH on blood phosphorus

Phosphate concentration declines with the increase in PTH. PTH leads to breakdown of bones. This releases more calcium than phosphorus. Phosphorus excretion via kidneys is promoted by PTH.

Though, PTH promotes phosphorus absorption via intestines.

So, having more of PTH in blood would mean that you have plenty of calcium in your blood stream. Your bones actually become porous, as they area forced to release stored calcium in them.

This happens in conditions like hyper parathyroidism.

You Should Know

Teriparatide is a part of PTH, not exactly the same.
Moreover, its action is similar but not identical to PTH.
Taking these injections is not identical as having hyper parathyroidism, where PTH amounts are very high.
Whereas, high PTH decreases bone density, teriparatide increases bone density.

Dose

Subcutaneous injections of 20 mcg of teriparatide, given daily at approximately the same time.

Uses

Treating post menopausal women, who are at a higher risk of fractures.
Men or women receiving prolonged steroid therapy due to some disease and are at a higher risk of getting fractures.
Hypoparathyroid individuals.

Teriparatide Injection cost

These injections are expensive and not easily available. A one month supply costs approximately $560. While drug therapy for osteoporosis with medicines, like alendronate or risedronate, cost $67.

Drug Not To Be Used If

Patients who are at a higher risk of osteosarcoma.
Those with Paget’s disease of bone, have received radiation therapy involving skeleton.
Young people with open epiphysis.
Unexplained elevated levels of alkaline phosphatase.

Precautions

The drug is to be administered subcutaneously, preferably at the same time each day.
Adequate calcium and vitamin D should be taken during the treatment.

Side Effects

Nausea and feeling your heart beats. This may happen just after you take the injection. It’s better to sit down or lie down for some time after taking the injection. Keep a glass of water near you. You may have it after the injection is given.

Get up after relaxing for some time.