Simvastatin Side Effects

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

Part of cardiovascular side effects.

What is simvastatin?

Simvastatin contains the active ingredient Simvastatin.

• Active ingredient — Simvastatin
• Registration number — 36/7.5/0370; 36/7.5/0371; 36/7.5/0372
• Registration holder — Unimed Healthcare (Pty) Ltd

It is approved for:

• a raised cholesterol level in your blood (primary hypercholesterolaemia) or elevated fat levels in your blood (mixed hyperlipidaemia)
• a hereditary illness (heterozygous familial hypercholesterolaemia) that increases the cholesterol level in your blood. UNISIM is also used if you have:
• coronary heart disease (CHD) and high cholesterol levels not responding to diet

Common side effects of simvastatin

Not everyone gets side effects. The effects below are those listed in the South African approved leaflet, grouped using the leaflet’s own frequency wording.

Frequent side effects

• feeling sick (nausea), being sick (vomiting), wind, indigestion, stomach pain
• myalgia (soreness and achiness in the muscles that can range from mild to severe)
• muscle cramps

Less frequent side effects

• tiredness, headaches, being short of breath when exercising, dizziness and looking pale (low number of red blood cells), frequent infections such as fever, severe chills, sore throat or mouth (low number of white blood cells)
• diabetes
• trouble sleeping
• headache, dizziness, tiredness, pins and needles (paraesthesia)
• poor memory, memory loss, confusion
• photosensitivity, blurred vision, impaired vision
• shortness of breath, hypersensitivity pneumonitis (inflamed lungs)
• constipation, diarrhoea
• skin rash, itching, loss of hair (alopecia), urticaria (hives)
• lichenoid drug eruptions (violaceous, scaling papules and plaques that are typically symmetrical and widespread)
• muscle pain, muscle cramps, muscle inflammation, unusual weakness, muscle rupture
• breast enlargement in men (gynaecomastia)

Frequency unknown side effects

• weight gain
• depression
• sleep disturbances, including nightmares
• weakness and rapid fatigue of muscles under voluntary control (myasthenia gravis). The symptoms might only be limited to eye muscles (ocular myasthenia)
• interstitial lung disease
• respiratory infections, bronchitis, sinusitis
• immune-mediated necrotising myopathy (IMNM)
• erectile dysfunction
• sexual dysfunction. Effect on Laboratory tests
• low level blood cells (red, white and platelets)
• increased creatine kinase (from muscle) in blood
• presence of myoglobin in urine (marker for muscle breakdown)
• increase in blood transaminase, alkaline phosphatase, gamma glutamyl transpeptidase (liver function enzymes)
• increase in blood glucose

Serious side effects and warning signs

This leaflet does not set out a separate list of serious side effects. The general warning signs below apply to any medicine.

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

The approved leaflet identifies the following cautions and factors.

Do not use it at all if

• if you are hypersensitive (allergic) to simvastatin or other statin or any of the other ingredients of UNISIM
• if you currently have liver problems
• if you have unexplained persistent elevation of serum transaminase (liver enzymes)
• if you are pregnant or breastfeeding
• if you are taking one or more of the following medicines at the same time:
• itraconazole, voriconazole, ketoconazole, or posaconazole (medicines for fungal infections)
• erythromycin, clarithromycin, or telithromycin (antibiotics for infections)
• HIV protease inhibitors such as indinavir, nelfinavir, ritonavir, and saquinavir (HIV protease inhibitors are used for HIV infections)
• boceprevir, telaprevir (medicine used to treat hepatitis C)
• nefazodone (a medicine for depression)
• cobicistat (used to treat HIV infection)
• gemfibrozil (a medicine for lowering cholesterol)
• ciclosporin (a medicine often used in organ transplant patients)
• danazol (a man-made hormone used to treat endometriosis: a female health disorder that occurs when cells from the lining of the womb (uterus) grow in other areas of the body
• lomitapide (used to lower familial cholesterol) with more than 40 mg of UNISIM. Safety of UNISIM in porphyria (a group of rare blood pigment disorders) has not been established

Use with care, and tell your doctor, if

• Tell your doctor if you drink large amounts of alcohol
• Tell your doctor if you have ever had liver disease. UNISIM may not be right for you
• Tell your doctor if you develop kidney failure resulting from muscle breakdown (rhabdomyolysis). Other factors which can lead to kidney failure include severe infection, low blood pressure, severe problems with your metabolism (a process by which your body uses to get or make energy from the food you eat), problems with your hormonal system, imbalance of electrolyte (such as potassium, sodium), uncontrolled fits, operation or injury
• Tell your doctor if you are due to have an operation
• You may need to stop taking UNISIM for a short time
• Your doctor should do a blood test before you start taking UNISIM
• This is to check how well your liver is working
• Your doctor may also want you to have blood tests to check how well your liver is working after you start taking UNISIM
• While you are taking UNISIM your doctor will monitor you closely if you have diabetes or are at risk of developing diabetes. You are likely to be at risk of developing diabetes if you have high levels of sugars and fats in your blood, are overweight and have high blood pressure
• If you are using any other medicines such as immunosuppressants, fibrates (except fenofibrate), lipid lowering doses of niacin, amiodarone, amlodipine, verapamil, diltiazem or daptomycin (also see Do not take UNISIM)
• If you are Asian
• Tell your doctor if you have severe lung disease. Contact your doctor immediately if you experience unexplained muscle pain, tenderness, or weakness
• This is because on rare occasions, muscle problems can be serious, including muscle breakdown resulting in kidney damage and, rarely, death. You should stop UNISIM immediately, if you have been diagnosed with muscle problems (myopathy) or suspect that you have myopathy. Your doctor may monitor creatine kinase (an enzyme marker for muscle problems) levels in your blood periodically especially when you are starting UNISIM therapy or your dose of UNISIM is increased. The risk of muscle breakdown is greater at higher doses of UNISIM, particularly the 80 mg dose. The risk of muscle breakdown is also greater in certain patients. You might be more at risk to develop muscle problems and should speak with your doctor if any of the following applies:
• if you are older than 65 years
• if you are a female
• if you have kidney problems
• if you have uncontrolled hypothyroidism
• if you have a personal or family history of muscle disorders
• if you have previously experienced muscle disorders with statin or fibrate use
• if you consume large amounts of alcohol. UNISIM may cause weakness and rapid fatigue of muscles under voluntary control (myasthenia gravis). The symptoms might only be limited to eye muscles (ocular myasthenia). Children and adolescents It is not recommended for children as the safety and efficacy has not been established. Other medicines with UNISIM Always tell your healthcare professional if you are taking any other medicine. (This includes complementary or traditional medicines.) It is particularly important to tell your doctor if you are taking any of the following medicines. Taking UNISIM with any of these medicines can increase the risk of muscle problems (some of these have already been listed in the above section “Do not take UNISIM”)
• ciclosporin (a medicine used in organ transplant patients)
• danazol (a man-made hormone used to treat endometriosis)
• medicines with the active ingredient like itraconazole, ketoconazole, fluconazole, voriconazole or posaconazole (medicines for fungal infections)
• fibrates like gemfibrozil (medicines for lowering cholesterol)
• erythromycin, clarithromycin, telithromycin or fusidic acid (medicines for bacterial infections)
• HIV protease inhibitors such as indinavir, nelfinavir, ritonavir, and saquinavir (medicines for AIDS)
• nefazodone (a medicine for depression)
• medicines with the active ingredient cobicicstat (used to treat HIV infection)
• boceprevir, telaprevir, elbasvir or grazoprevir (medicine used to treat hepatitis C)
• oral fusidic acid (medicine used to treat a bacterial infection). If you need to take oral fusidic acid you will need to temporarily stop taking this medicine. Your doctor will tell you when it is safe to start UNISIM again. Taking UNISIM with fusidic acid may rarely lead to muscle weakness, tenderness or pain (rhabdomyolysis)
• amiodarone (used to treat an irregular heartbeat)
• verapamil, diltiazem, or amlodipine (used to treat high blood pressure, chest pain associated with heart disease, or other heart conditions)
• lomitapide (used to treat a serious and rare genetic cholesterol condition)
• daptomycin (a medicine used to treat complicated skin infections and bacteraemia). It is possible that side effects affecting the muscles may be higher when this medicine is taken during treatment with simvastatin (e.g. UNISIM). Your doctor may decide that you stop treatment with UNISIM while taking daptomycin for a while
• ticagrelor (antiplatelet medicine)
• colchicine (used to treat gout). Also, tell your doctor or pharmacist if you are taking or have recently taken any of the following:
• medicines to prevent blood clots, such as warfarin, (anticoagulants)
• cholestyramine (another medicine for lowering cholesterol)
• niacin (another medicine for lowering cholesterol)
• digoxin (a medicine for used to treat heart problems)
• rifampicin (used to treat tuberculosis). Also tell your doctor if you are taking niacin (nicotinic acid) or a niacin-containing product and are Chinese. You should also tell any doctor who is prescribing a new medicine for you that you are taking UNISIM. UNISIM with food and drink Grapefruit juice contains one or more components that alter how the body uses some medicines, including UNISIM. Consuming grapefruit juice should be avoided

Pregnancy and breastfeeding

• You should not take UNISIM if you are pregnant or breastfeeding your baby
• Do not take UNISIM if you are pregnant, trying to get pregnant or think you may be pregnant
• If you get pregnant while taking UNISIM, stop taking it immediately and contact your doctor
• Do not take UNISIM if you are breastfeeding, because it is not known if the medicine is passed into breast milk
• If you are pregnant or breastfeeding your baby, think you may be pregnant or are planning to have a baby, please consult your doctor, pharmacist or other healthcare professional for advice before taking UNISIM

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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