Forteo

Indications

Teriparatide is used to treat osteoporosis (thin, fragile bones) in people at high risk of fractures, including women after menopause, men, and people whose osteoporosis is caused by long-term corticosteroid (steroid) treatment. It is usually chosen when fractures have already happened or other treatments are not suitable or have not worked.

How It Works

Teriparatide is a man-made form of the active part of parathyroid hormone, a natural hormone that controls calcium and bone. Given as a small daily injection, it stimulates bone-forming cells (osteoblasts) more than bone-removing cells. This builds new bone, increases bone density and strength, and lowers the risk of spine and other fractures.

Dosage and Administration

Use as prescribed. The usual dose is 20 micrograms once a day, injected under the skin of the thigh or abdomen using a pre-filled pen. A doctor or nurse will show you how to inject it yourself. Inject at about the same time each day; the first doses may be taken sitting or lying down in case of dizziness. Treatment is usually limited to a total of 24 months over your lifetime. Your doctor may advise calcium and vitamin D supplements if your diet does not provide enough.

Interactions

Teriparatide can briefly raise blood calcium, which may increase the risk of side effects from Digoxin; tell your doctor if you take it. Thiazide diuretics and calcium or vitamin D supplements may add to the rise in calcium. Tell your doctor about all medicines you use, including other osteoporosis treatments.

Contraindications

Do not use if you are allergic to Teriparatide; have high blood calcium; have severe kidney disease; have Paget's disease of bone or other metabolic bone diseases (except osteoporosis); have unexplained raised alkaline phosphatase; have had radiation therapy involving the bones; have bone cancer or cancer that has spread to the bones; are pregnant or breastfeeding; or are a child or young adult whose bones are still growing.

Side Effects

Common side effects include nausea, headache, dizziness or light-headedness on standing (especially after the first doses), leg cramps, joint pain, tiredness, and redness, pain or bruising at the injection site. Blood calcium may rise slightly a few hours after the injection, and uric acid may increase.

Get urgent medical help if you have signs of a serious allergic reaction (swelling of the face or throat, difficulty breathing), fainting, fast or irregular heartbeat, or signs of very high calcium such as severe nausea, vomiting, constipation, confusion, extreme tiredness or muscle weakness. Tell your doctor about persistent bone pain.

Pregnancy and Lactation

Do not use during pregnancy or breastfeeding. Women who could become pregnant should use effective contraception during treatment and should stop it if they become pregnant.

Precautions and Warnings

• Blood calcium and kidney function may be checked during treatment.
• Use with care in people with kidney stones, moderate kidney problems or heart disease.
• In animal studies very high doses caused bone tumours (osteosarcoma); this has not been confirmed in humans, but treatment length is limited and people at higher risk should not use it.
• Do not drive if you feel dizzy after the injection.
• Never share your pen with anyone, even if the needle is changed.

Overdose

An overdose may cause high blood calcium, nausea, vomiting, dizziness, headache and low blood pressure on standing. Contact a doctor; treatment involves stopping the medicine, checking calcium and supportive care.

Therapeutic Class

Parathyroid hormone analogue, bone-forming (anabolic) agent for osteoporosis

Storage

Store in a refrigerator at 2 to 8°C at all times, do not freeze, and keep the cap on the pen to protect from light. Return the pen to the fridge straight after each use. Use the pen within 28 days of first use, then throw it away safely. Keep out of the reach of children.