Pulmonary embolism - Treating pulmonary embolism

If you are diagnosed with a pulmonary embolism, emergency treatment may be needed to dissolve the blood clot. You will also need medication to stop your blood clotting so easily.

About half of all pulmonary embolism cases occur while a person is in hospital. If you are not in hospital, you will be admitted so that you can receive treatment. You will be given oxygen to help you breathe comfortably.

If your pulmonary embolism is severe and life-threatening, medication to dissolve the blood clot will be prescribed. This is known as thrombolytic therapy.

The next step is to prevent further blood clots from forming using anticoagulant medicines.

Anticoagulants

As well as reducing the blood's clotting ability, anticoagulants stop blood clots from getting bigger. They can also help prevent part of the blood clot breaking off and becoming lodged in another part of your bloodstream (an embolism).

Anticoagulants are often referred to as blood-thinning medicines but they do not actually thin the blood. They alter chemicals in the blood to prevent clots forming so easily.

Heparin and warfarin are the two anticoagulants that are usually prescribed to treat pulmonary embolisms. Heparin is usually used first because it immediately prevents another clot from forming. Warfarin can take longer to start working but it is also effective in preventing further blood clots.

Heparin and warfarin are discussed in more detail below.

Heparin

There are two different types of heparin  standard heparin and low molecular weight heparin (LMWH). Standard heparin is given intravenously, which means it is injected directly into a vein, whereas LMWH is injected into the skin.

If you have standard heparin you will need to be admitted to hospital so that the medication can be fed into your vein through an intravenous line. The medicine can work differently from person to person so the dosage must be carefully monitored and adjusted if necessary.

LMWH works slightly differently from standard heparin. It contains smaller molecules which means that its effects are more reliable. A dose of LMWH can be given as one injection and you will not have to stay in hospital to be monitored.

Both standard heparin and LMWH can cause many different side effects, including:

• a skin rash
• headaches 
• an upset stomach
• bleeding
• a general feeling of being unwell
• weakening of the bones (if taken over a long period of time)

In rare cases, heparin can also cause a severe reaction that makes existing blood clots worse and enables new ones to develop.

This reaction and weakening of your bones are less likely to occur if you are taking LMWH. Therefore, in most cases LMWH will be recommended.

Read more about the side effects of heparin.

Warfarin

Warfarin is taken in tablet form. You may need to take it for up to six months after your initial treatment with heparin to prevent further blood clots developing. In some cases, warfarin may need to be taken for the rest of your life.