Heparin (the generic name for a range of drugs, including HepLok in the US, and PumpHep and Unihep in the UK) is an anticoagulant, often used as a "just in case" therapy if there is a danger of heart attack or stroke and to prevent blood clots afte

Its most common side effect is hemorrhage. Because bleeding can occur at virtually any part of the body, it should not be given to those who are at an increased risk of hemorrhage, such as those suffering from peptic ulcers, bacterial heart infection, and even during menstruation. Women over 60 are also at greater risk.

Extensive reviews of the available literature show that much depends on the dose and method of administration and whether or not it is given in conjunction with other drugs, particularly anti platelets such as aspirin. Heparin is generally given either as a subcutaneous injection or an intravenous infusion. Some patients experience local irritation following deep, subcutaneous injections. Intramuscular injections are not recommended as they seem to have the highest rate of complications such as skin irritation, ulceration, hematoma and mild pain.

When heparin is given with aspirin the risk of hemorrhage increases and some of the most serious complications, such as adrenal and ovarian hemorrhage, may be difficult to detect.

It has also been shown to cause osteoporosis.

Among the most dramatic side effects of heparin use is "white clot syndrome" recurrent thrombosis which can occur in as many as 30 per cent of patients, according to the Physicians' Desk Reference. This can lead to skin necrosis, gangrene leading to amputation, heart failure, pulmonary embolism, stroke and even death.