Clexane side effects

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In medicine, the term "clot" refers to the natural coagulation of blood. Whenever you receive an injury or incision, your body produces a clot in order to stave the bleeding.

It is possible, however, for blood clots to form in your body when they are not needed, posing a risk for serious medical complications like strokes or heart attacks. If you develop a clot, your doctor is likely to utilise medications to help dissolve the mass of blood before it causes any complications. In the United Kingdom, doctors commonly rely upon an injection known as Clexane or enoxaparin for such purposes. Despite its effectiveness, Clexane is not for everyone as it presents several risks for side effects and complications in some patients.


Approximately 16 per cent of patients who receive Clexane injections experience a shortage of red blood cells or anaemia, making this the most common side effect of the drug. Anemia causes a number of symptoms, including fatigue, paleness, coldness in your extremities and shortness of breath. Left untreated, anaemia causes some patients to become too tired to carry out normal day-to-day activities. More serious complications are also possible, such as irregular heartbeat, permanent nerve damage and impaired mental functioning. Because of this, your doctor is likely to administer blood tests on a regular basis while you receive Clexane in order to ensure your red blood cell counts remain within normal levels.

Other minor side effects

Clexane also has the potential to cause a number of other troublesome or annoying, but not dangerous, side effects. Approximately 8 per cent of those who receive Clexane injections develop fevers. Gastrointestinal side effects like nausea and diarrhoea occur in 2 to 3 per cent of patients. Around 3 per cent of users notice dark spots at the site of the injection, while another 2 per cent experience pain at the site. The most common reaction at the site of injection is the formation of a haematoma or small blood clot where the injection is given. This occurs in 5 per cent of patients.


There are some medications that have the potential to cause the dangerous side effect of excessive bleeding when used in conjunction with Clexane. Pain relieving non-steroidal anti-inflammatory drugs (NSAIDs) are one such medication. NSAIDs, even over-the-counter NSAIDs like Tylenol, aspirin and ibuprofen, have the potential to cause bleeding emergencies when used with Clexane. Blood thinners like dipyridamole or oral anticoagulants like warfarin also increase your risk of haemorrhages when taken with Clexane.


When combined with certain drugs, Clexane often causes increases in blood potassium levels. In some cases, this leads to a condition called hyperkalemia, which can damage or interfere with your heart and cardiovascular system. ACE inhibitors like lisinopril, diuretics and the immunosuppressant ciclosporine are amongst the medications that contribute to the development of hyperkalemia. Additionally, you should avoid taking potassium supplements while undergoing treatment with Clexane.


In addition to minor side effects and the risk of interactions, Clexane has the potential to cause serious medical complications. After surgery involving an epidural anesthetic, patients taking Clexane sometimes develop blood clots along their spine. Inflammation or damage to your liver is also possible while taking Clexane. Some patients develop a shortage of blood platelets or thrombocytopenia while undergoing treatment with the drug, increasing the risk of developing bleeding inside the skull.