Blood Clots
Using a combined hormonal contraceptive such as Marvelon, increases your risk of developing a blood clot compared with not using one. In rare cases a blood clot can block blood vessels and cause serious problems.
Blood clots can develop
- in veins (referred to as a ‘venous thrombosis’, ‘venous thromboembolism’ or VTE)
- in the arteries (referred to as an ‘arterial thrombosis’, ‘arterial thromboembolism’ or ATE).
Recovery from blood clots is not always complete. Rarely, there may be serious lasting effects or, very rarely, they may be fatal.
It is important to remember that the overall risk of a harmful blood clot due to Marvelon is small.
How to recognise a blood clot
Seek urgent medical attention if you notice any of the following signs or symptoms.
Are you experiencing any of these signs?
- swelling of one leg or along a vein in the leg or foot especially when accompanied by:
- pain or tenderness in the leg which may be felt only when standing or walking
- increased warmth in the affected leg
- change in colour of the skin on the leg e.g. turning pale, red or blue
What are you possibly suffering from?
Deep vein thrombosis
Are you experiencing any of these signs?
- sudden unexplained breathlessness or rapid breathing,
- sudden cough without an obvious cause, which may bring up blood,
- sharp chest pain which may increase with deep breathing,
- severe light headedness or dizziness,
- rapid or irregular heartbeat,
- severe pain in your stomach.
If you are unsure, talk to a doctor as some of these symptoms such as coughing or being short of breath may be mistaken for a milder condition such as a respiratory tract infection (e.g. a ‘common cold’).
What are you possibly suffering from?
Pulmonary embolism
Are you experiencing any of these signs?
Symptoms most commonly occur in one eye:
- immediate loss of vision or
- painless blurring of vision which can progress to loss of vision.
What are you possibly suffering from?
Retinal vein thrombosis (blood clot in the eye)
Are you experiencing any of these signs?
- chest pain, discomfort, pressure, heaviness;
- sensation of squeezing or fullness in the chest, arm or below the breastbone;
- fullness, indigestion or choking feeling;
- upper body discomfort radiating to the back, jaw, throat, arm and stomach;
- sweating, nausea, vomiting or dizziness;
- extreme weakness, anxiety, or shortness of breath;
- rapid or irregular heartbeats.
What are you possibly suffering from?
Heart attack
Are you experiencing any of these signs?
- sudden weakness or numbness of the face, arm or leg, especially on one side of the body;
- sudden confusion, trouble speaking or understanding;
- sudden trouble seeing in one or both eyes;
- sudden trouble walking, dizziness, loss of balance or coordination;
- sudden, severe or prolonged headache with no known cause;
- loss of consciousness or fainting with or without seizure.
Sometimes the symptoms of stroke can be brief with an almost immediate and full recovery, but you should still seek urgent medical attention as you may be at risk of another stroke.
What are you possibly suffering from?
Stroke
Are you experiencing any of these signs?
- swelling and slight blue discolouration of an extremity;
- severe pain in your stomach (acute abdomen)
What are you possibly suffering from?
Blood clots blocking other blood vessels
Blood clots in a vein
What can happen if a blood clot forms in a vein?
- The use of combined hormonal contraceptives has been connected with an increase in the risk of blood clots in the vein (venous thrombosis). However, these side effects are rare. Most frequently, they occur in the first year of use of a combined hormonal contraceptive.
- If a blood clot forms in a vein in the leg or foot it can cause a deep vein thrombosis (DVT).
- If a blood clot travels from the leg and lodges in the lung it can cause a pulmonary embolism.
- Very rarely a clot may form in a vein in another organ such as the eye (retinal vein thrombosis).
When is the risk of developing a blood clot in a vein highest?
The risk of developing a blood clot in a vein is highest during the first year of taking a combined hormonal contraceptive for the first time. The risk may also be higher if you restart taking a combined hormonal contraceptive (the same product or a different product) after a break of 4 weeks or more.
After the first year, the risk gets smaller but is always slightly higher than if you were not using a combined hormonal contraceptive.
When you stop Marvelon your risk of a blood clot returns to normal within a few weeks.
What is the risk of developing a blood clot?
The risk depends on your natural risk of VTE and the type of combined hormonal contraceptive you are taking.
The overall risk of a blood clot in the leg or lung (DVT or PE) with Marvelon is small.
- Out of 10,000 women who are not using any combined hormonal contraceptive and are not pregnant, about 2 will develop a blood clot in a year.
- Out of 10,000 women who are using a combined hormonal contraceptive that contains levonorgestrel, norethisterone, or norgestimate about 5-7 will develop a blood clot in a year.
- Out of 10,000 women who are using a combined hormonal contraceptive that contains desogestrel such as Marvelon between about 9 and 12 women will develop a blood clot in a year.
- The risk of having a blood clot will vary according to your personal medical history (see “Factors that increase your risk of a blood clot” below).
Risk of developing a blood clot in a year
Women who are not using a combined hormonal pill/patch/ring and are not pregnant:
About 2 out of 10,000 women
Women using a combined hormonal contraceptive pill containing levonorgestrel, norethisterone or norgestimate:
About 5-7 out of 10,000 women
Women using Marvelon
About 9-12 out of 10,000 women
Factors that increase your risk of a blood clot in a vein
The risk of a blood clot with Marvelon is small but some conditions will increase the risk. Your risk is higher:
- if you are very overweight (body mass index or BMI over 30kg/m2);
- if one of your immediate family has had a blood clot in the leg, lung or other organ at a young age (e.g. below the age of about 50). In this case you could have a hereditary blood clotting disorder;
- if you need to have an operation, or if you are off your feet for a long time because of an injury or illness, or you have your leg in a cast. The use of Marvelon may need to be stopped several weeks before surgery or while you are less mobile. If you need to stop Marvelon ask your doctor when you can start using it again;
- as you get older (particularly above about 35 years);
- if you gave birth less than a few weeks ago.
The risk of developing a blood clot increases the more conditions you have.
Air travel (> 4 hours) may temporarily increase your risk of a blood clot, particularly if you have some of the other factors listed.
It is important to tell your doctor if any of these conditions apply to you, even if you are unsure. Your doctor may decide that Marvelon needs to be stopped.
If any of the above conditions change while you are using Marvelon, for example a close family member experiences a thrombosis for no known reason; or you gain a lot of weight, tell your doctor.
Blood clots in an artery
What can happen if a blood clot forms in an artery?
Like a blood clot in a vein, a clot in an artery can cause serious problems. For example, it can cause a heart attack or a stroke.
Factors that increase your risk of a blood clot in an artery
It is important to note that the risk of a heart attack or stroke from using Marvelon is very small but can increase:
- with increasing age (beyond about 35 years);
- if you smoke. When using a combined hormonal contraceptive like Marvelon you are advised to stop smoking. If you are unable to stop smoking and are older than 35 your doctor may advise you to use a different type of contraceptive;
- if you are overweight;
- if you have high blood pressure;
- if a member of your immediate family has had a heart attack or stroke at a young age (less than about 50). In this case you could also have a higher risk of having a heart attack or stroke;
- if you, or someone in your immediate family, have a high level of fat in the blood (cholesterol or triglycerides);
- if you get migraines, especially migraines with aura;
- if you have a problem with your heart (valve disorder, disturbance of the rhythm called atrial fibrillation);
- if you have diabetes.
If you have more than one of these conditions or if any of them are particularly severe the risk of developing a blood clot may be increased even more.
If any of the above conditions change while you are using Marvelon, for example you start smoking, a close family member experiences a thrombosis for no known reason; or you gain a lot of weight, tell your doctor.
Tell your doctor, pharmacist or family planning nurse if you are using, have recently used or might use any other medicines or herbal products, even those not prescribed. Also tell any other doctor or dentist who prescribes another medicine (or your pharmacist) that you use Marvelon. This is because Marvelon can also affect how well other medicines work, causing either an increase in effect (e.g., ciclosporin) or a decrease in effect (e.g., lamotrigine). Remind your doctor if you are taking these in case your treatment needs to be adjusted.
Also check the leaflets that come with all your medicines to see if they can be taken with hormonal contraceptives.
Some medicines may stop Marvelon from working properly. These include medicines used for the treatment of:
- epilepsy (primidone, phenytoins, phenobarbital, carbamazepine, oxcarbazepine, topiramate, felbamate, modafinil);
- tuberculosis (rifampicin);
- HIV infection (ritonavir, nelfinavir, nevirapine, efavirenz);
- Hepatitis C virus infection (e.g., boceprevir, telaprevir);
- other infectious disease (e.g., griseofulvin);
- high blood pressure in the blood vessels of the lungs (bosentan);
- depressive moods (the herbal remedy St. John’s wort).
If you are taking medicines or herbal products that might make Marvelon less effective, a barrier contraceptive method should also be used. Since the effect of another medicine on Marvelon may last up to 28 days after stopping the medicine, it is necessary to use the additional barrier contraceptive method for that long.
Do not use Marvelon if you have Hepatitis C and are taking medicinal products containing ombitasvir/ paritaprevir/ ritonavir and dasabuvir or glecaprevir/ pibrentasvir as this may cause increases in liver function blood test results (increase in ALT liver enzyme).
Your doctor will prescribe another type of contraceptive prior to start of the treatment with these medicinal products.
Marvelon can be restarted approximately 2 weeks after completion of this treatment.
See section 2.1 “Do not use Marvelon”.