Blood thinners Side Effects

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Answer the side-effect intent for blood thinners without diagnosing; distinguish common from serious reactions and give safe next-step/reporting guidance.

What is blood thinners?

Blood thinners covers several products registered in South Africa, not one. They work in a similar way, and their approved leaflets do not list identical side effects.

The medicines covered here, and the leaflet used for each:

• warfarin — HEAMAWARIN, Biotech Laboratories (Pty) Ltd (Tablet)
• enoxaparin — CRUSIA 20/ 40/ 60/ 80/ 100, ADCOCK INGRAM LIMITED (SOLUTION FOR INJECTION)
• rivaroxaban — RIVAR 10, Innovata Pharmaceuticals (Pty) Ltd (Tablet)
• apixaban — VIBANEX, Viatris South Africa (Pty) Ltd (Film-coated tablets)
• clopidogrel — CLOPIWIN PLUS, sanofi-aventis south africa (pty) ltd (Film-coated tablets.)

Common side effects of blood thinners

Each medicine in this group has its own approved leaflet, and the effects below are the ones that leaflet lists. They are shown separately rather than combined, because the leaflets do not agree on what to list or how to word it.

Warfarin (HEAMAWARIN)

• lower-than-normal number of leukocytes (white blood cells) in the blood
• too many granulocytes (certain type of white blood cells) in the blood
• reduced blood clotting (by inhibiting vitamin K synthesis), may also increase the risk of bleeding
• diarrhoea
• nausea
• vomiting
• feeling bloated
• loss of appetite
• stomach pain
• kidney damage (leading to swelling in different parts of the body, abnormal amount of protein in the urine or difficulty passing urine). Side effects with unknown frequency
• fever
• low number of red blood cells (anaemia)

The leaflet lists 10 more. Read the full leaflet.

Enoxaparin (CRUSIA 20/ 40/ 60/ 80/ 100)

• headache
• increases in liver enzymes
• itchy red skin
• hives, urticaria
• bruising or pain at the injection site
• you bruise more easily than usual – this could be because of a blood problem with low platelet counts
• high platelet counts in the blood
• decreased red blood cell count
• sudden severe headache – this could be a sign of bleeding in the brain
• a feeling of tenderness and swelling in your stomach – you may have bleeding in your stomach
• bleeding at wound sites
• nose bleeds

The leaflet lists 11 more. Read the full leaflet.

Rivaroxaban (RIVAR 10)

• reduction in red blood cells which can make the skin pale and cause weakness or breathlessness
• bleeding in the stomach or bowel, urogenital bleeding (including blood in the urine and heavy menstrual bleeding), nosebleed, bleeding in the gum
• bleeding into the eye (including bleeding from the whites of the eyes)
• bleeding into tissue or a cavity of the body (haematoma, bruising)
• coughing up blood
• bleeding from the skin or under the skin
• bleeding following an operation
• oozing of blood or fluid from surgical wound
• swelling in the limbs
• pain in the limbs
• impaired function of the kidneys (may be seen in tests performed by your doctor)
• fever

The leaflet lists 23 more. Read the full leaflet.

Apixaban (VIBANEX)

• Bleeding including:
• In your eyes
• From your rectum
• From a haemorrhoid
• In your mouth or blood in your spit when coughing
• From your gums
• From the vagina
• Bruising and swelling
• Anaemia which may cause tiredness or paleness
• Reduced number of platelets in your blood (which can affect clotting)
• Low blood pressure which may make you feel faint or have a quickened heartbeat
• Nausea (feeling sick)

The leaflet lists 15 more. Read the full leaflet.

Clopidogrel (CLOPIWIN PLUS)

• a serious skin reaction called acute generalized exanthematous pustulosis (AGEP) – symptoms may include a red, scaly widespread rash with bumps under the skin (including your skin folds, trunk, and upper extremities) and blisters filled with white/yellow fluid accompanied by fever
• a serious skin reaction called drug rash with eosinophilia and systemic symptoms (DRESS) or drug-induced hypersensitivity syndrome (DiHS) – symptoms may include rash, often itchy, fever, inflammation of internal organs, most commonly the liver
• inflammation of the pancreas with symptoms such as severe upper abdominal pain, the abdominal pain may radiate to your back, nausea, vomiting, diarrhoea, tenderness when touching your abdomen, fever
• lung problems called non-cardiogenic pulmonary oedema causing a fluid build-up in the lung – symptoms may include dry cough, fever, difficulty breathing when lying down, chest pain, shortness of breath
• breathing difficulties, sometimes associated with coughing
• a condition where a certain type of white blood cell called eosinophils accumulates in your lungs (eosinophilic pneumonia) – symptoms may include fever, chest pain worsened by deep breathing, shortness of breath, cough and generally feeling unwell
• numbness or problems with co-ordination
• low blood sugar – symptoms may include feeling shaky, anxious or nervous, light- headed, dizzy, chills, sweating or clammy skin, fast heartbeat
• insulin autoimmune syndrome a condition which can cause persistent low blood sugar levels
• increase in blood pressure
• decrease in blood pressure
• severe abdominal pain with or without back pain

The leaflet lists 22 more. Read the full leaflet.

Serious side effects and warning signs

None of the leaflets reviewed set out a separate serious-effects list.

General warning signs that apply to any medicine

How long can side effects last?

How long a side effect lasts depends on the effect, the product, how long it has been used, and the person. Some effects ease within days as the body adjusts. Others continue for as long as the product is used. A few can persist after stopping, and some need review rather than waiting.

• Settling effects — mild effects that ease over the first days or weeks of use
• Ongoing effects — effects that continue while the product is being used and improve after stopping
• Persistent effects — effects that continue after stopping and need medical review
• Delayed effects — effects that appear after weeks or months rather than immediately

Which of these applies to a particular effect is a clinical question. If a side effect is not settling, is getting worse, or is affecting your daily life, that is worth a conversation with a pharmacist or doctor regardless of how long it has been going on.

Factors that may affect side effects

Cautions from each medicine’s approved leaflet.

Warfarin (HEAMAWARIN)

Do not use it at all if:

• if you are hypersensitive (allergic) to warfarin sodium or any of the other ingredients of Heamawarin listed in section 6.1
• if you recently had a stroke caused by bleeding in the brain
• if you have a bleeding situation
• if you have any bleeding disorder or disease
• if you had surgery within the last 72 hours or are going to have surgery in the next 72 hours
• if you have a peptic ulcer or other stomach disease that causes you to bleed internally

Use with care, and tell your doctor, if:

• if you have a genetic disorder called protein C deficiency making you prone to blood clots (thrombophilia)
• you should not stop your treatment with Heamawarin abruptly. Your doctor will decrease your dose gradually over three to four weeks
• if you have a Vitamin K deficiency
• medicines like Heamawarin, which work against vitamin K, might put you at risk for weaker bones (increased risk in fractures). You need extra attention to avoid this problem
• if you suffer from dietary deficiency, are on antibiotic treatment, suffer from vascular disease, diabetes or have allergic disorders
• if you had recent ischaemic stroke (caused by blockage of blood vessels in the brain)

Enoxaparin (CRUSIA 20/ 40/ 60/ 80/ 100)

Do not use it at all if:

• if you are hypersensitive (allergic) to enoxaparin sodium, or any of the other ingredients of CRUSIA (listed in section 6)
• if you are hypersensitive (allergic) to heparin or other low molecular weight heparins such as nadroparin, tinzaparin or dalteparin
• you have had a reaction to heparin that caused a severe drop in the number of your clotting cells (platelets) within the last 100 days
• you have antibodies against enoxaparin in your blood
• you are bleeding heavily or have a condition with a high risk of bleeding, such as: o stomach ulcer, recent surgery of the brain or eyes, or recent bleeding stroke
• you are using CRUSIA to treat blood clots and are going to have within 24 hours: o a spinal or lumbar puncture o an operation with epidural or spinal anaesthesia. Do not use CRUSIA if any of the above apply to you. If you are not sure, talk to your doctor or pharmacist before using CRUSIA

Use with care, and tell your doctor, if:

• you have any problem with your spine, or you have had spinal surgery
• you have ever had a reaction to heparin that caused a severe drop in the number of your clotting cells (platelets)
• you have a history of gastric ulcer
• you have had a recent stroke
• you have high blood pressure
• you have diabetes or problems with blood vessels in the eye caused by diabetes (called diabetic retinopathy)

Rivaroxaban (RIVAR 10)

Do not use it at all if:

• If you are allergic (hypersensitive) to rivaroxaban or to any ingredients of RIVAR 10, (listed in section 6)
• If you have a bleeding disorder that you have inherited or bleeding excessively
• If you have a disease or condition in an organ of the body that increases the risk of serious bleeding (e.g. stomach ulcer, injury or bleeding in the brain, recent surgery of the brain or eyes)
• If you are taking medicines to prevent blood clotting (e.g. warfarin or heparin), except when changing anticoagulant treatment or while getting heparin through a venous or arterial line to keep it open
• If you have a liver disease which leads to an increased risk of bleeding
• If you are pregnant or breastfeeding RIVAR 10 should not be used in children and adolescents, under 18 years of age

Use with care, and tell your doctor, if:

• If you suffer from moderate or severe kidney disease
• If you suffer from moderate liver disease
• If you have an increased risk of bleeding such as: o bleeding disorders o very high blood pressure, not controlled by medical treatment o active ulcer or a recent ulcer of your stomach or bowel, diseases of your stomach or bowel that might result in bleeding, e.g. inflammation of the bowels or stomach, or inflammation of the oesophagus (gullet), e.g. due to gastroesophageal reflux disease (disease where stomach acid goes upwards into the oesophagus o a problem with the blood vessels in the back of your eyes (retinopathy) o recent bleeding in your brain (intracranial bleeding) o problems with your blood vessels in your brain or spinal column o a recent operation on your brain, spinal column or eye o a lung disease where your bronchi are widened and filled with pus (bronchiectasis), or previous bleeding from your lung
• If you have an artificial heart valve
• If you know that you have a disease called antiphospholipid syndrome (a disorder of the immune system that causes an increased risk of blood clots), tell your doctor who will decide if the treatment may need to be changed
• If your doctor determines that your blood pressure is unstable or another treatment or surgical procedure to remove the blood clot from your lungs is planned. If you need to have an operation:

Apixaban (VIBANEX)

Do not use it at all if:

• If you are hypersensitive (allergic) to apixaban or any of the other ingredients of VIBANEX (listed in section 6)
• If you are bleeding excessively
• If you have a severe kidney disease or if you are on dialysis
• If you have a disease in an organ of the body that increases the risk of serious bleeding (such as an active or a recent ulcer of your stomach or bowel, recent bleeding in your brain)
• If you have liver disease which leads to increased risk of bleeding (hepatic coagulopathy)
• If you are taking medicines to prevent blood clotting (e.g. warfarin, rivaroxaban, dabigatran or heparin), except when changing anticoagulant treatment, while having a venous or arterial line and you get heparin through this line to keep it open, or if a tube is inserted into your blood vessel (catheter ablation) to treat an irregular heartbeat (arrhythmia)

Use with care, and tell your doctor, if:

• An increased risk of bleeding, such as:
• Bleeding disorders, including conditions resulting in reduced platelet activity
• An active or a recent ulcer of your stomach or bowel
• Infection of the heart (bacterial endocarditis)
• Recent bleeding in your brain (haemorrhagic stroke)
• A recent operation on your brain, spinal column or eye

Clopidogrel (CLOPIWIN PLUS)

Do not use it at all if:

• If you are hypersensitive (allergic) to clopidogrel, aspirin or any of the other ingredients of CLOPIWIN PLUS, listed in section 6
• If you develop a skin rash while taking CLOPIWIN PLUS
• If you are allergic to other products called non-steroidal anti-inflammatory products usually used to treat painful and/or inflammatory conditions of muscles and joints
• If you have a history of gastrointestinal bleeding, gastrointestinal ulcer or gastrointestinal perforation related to previous use of a medicine called a non-steroidal anti-inflammatory drug (NSAID)
• If you have a medical condition that include the combination of asthma, nasal discharge (runny nose) and polyps (a type of growth in the nose)
• If you have a medical condition that is currently causing bleeding such as a stomach ulcer, haemophilia or bleeding within the brain or bowel or a history of such a condition

Use with care, and tell your doctor, if:

• If you have a risk of bleeding such as:
• a medical condition that puts you at risk of internal bleeding (such as a stomach ulcer)
• a blood disorder that makes you prone to internal bleeding (bleeding inside any tissues, organs or joints of your body)
• a recent serious injury
• a recent surgery (including dental)
• a planned surgery (including dental) in the next seven days

What to do if you experience side effects

If you think you are having a side effect, the response depends on how severe it is. Use the warning signs above first — if any of those apply, treat it as urgent.

If the symptom is severe or frightening

Get medical help immediately. Call 10177 for an ambulance, or 112 from a mobile phone, or go to the nearest emergency department. Take the product and its packaging with you if you can.

If the symptom is mild but bothering you

• Write down what the symptom is, when it started, and how it relates to when you take the product
• Check the leaflet that came with the product to see whether the symptom is listed
• Speak to your pharmacist — for many questions this is the fastest route to a useful answer
• Contact the prescriber if the symptom is affecting your daily life or is not settling

You can also report a suspected side effect in South Africa. Reporting does not replace getting medical advice, and you do not need to be certain the product was the cause.

When to seek urgent medical help

Some symptoms need medical attention straight away rather than an appointment in a few days. Do not wait to see whether they settle.

Get same-day medical advice if you have

• A high fever, or a rash together with feeling generally unwell
• Yellowing of the eyes or skin, or unusually dark urine
• Unusual bruising or bleeding that you cannot explain
• Severe or persistent vomiting or diarrhoea, especially if you cannot keep fluids down
• A sudden change in mood, or thoughts of harming yourself
• Any symptom that is rapidly getting worse

How to report a suspected side effect in South Africa

South Africa has an official system for reporting suspected side effects, run by the South African Health Products Regulatory Authority (SAHPRA). Reports from the public and from healthcare professionals are how safety signals get detected after a product is already in use.

Who can report

Anyone can report — you do not have to be a healthcare professional, and you do not need to prove that the product caused the problem. A suspicion is enough. Patients, caregivers and family members can all submit a report.

What to have ready

• The name of the product, its strength and form, and the batch number if you have it
• Why it was being used, and when it was started and stopped
• What the suspected reaction was, when it began, and how long it lasted
• Any other medicines, supplements or remedies being used at the same time
• Basic details about the person affected — age and sex are usually enough

How to report

SAHPRA accepts adverse reaction reports through its e-Services reporting system and through the Med Safety mobile app. Healthcare professionals can also report through the same routes. Current forms and access points are published on the SAHPRA site.

• SAHPRA Health Products Vigilance — the main vigilance and reporting hub
• SAHPRA e-Services — current adverse reaction reporting access

For a fuller walkthrough see how to report an adverse drug reaction.

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