Simvastatin

What is simvastatin?

Simvastatin is a medicine used to lower cholesterol levels in the blood. It belongs to a group of drugs called statins, which work by reducing the amount of cholesterol produced by the liver. It is given on prescription, both generically and under brand names such as Zocor, but it is also available in combination with other cholesterol medications like fenofibrate and ezetimibe[1].

What is simvastatin used for?

Simvastatin is primarily used to[1]: 

• Lower high cholesterol (hyperlipidaemia) 

• Prevent heart disease, including heart attacks and strokes, especially in people at high risk 

• Treat inherited conditions such as familial hypercholesterolaemia

How does simvastatin work?

Simvastatin blocks an enzyme in the liver (HMG-CoA reductase) involved in cholesterol production. This leads to lower ‘bad’ LDL cholesterol, higher ‘good’ HDL cholesterol and reduced triglycerides[1]. 

By lowering cholesterol, it helps prevent the build-up of fatty deposits (atheroma) in arteries and reduces the risk of cardiovascular events[1]. 

Who can take simvastatin?

Most adults and children over 10 years old can take simvastatin. However, it may not be suitable for people who[1]: 

• Have lung, liver, or kidney problems 

• Have an underactive thyroid 

• Have a history of myasthenia gravis or ocular myasthenia 

• Regularly drink large amounts of alcohol 

• Are pregnant, trying to get pregnant, or breastfeeding 

• Are allergic to simvastatin  

• Have ever had a muscle disorder (including fibromyalgia) 

Please tell your doctor or pharmacist about any conditions you may have or medication you take before you start treatment, and always follow the instructions in the Patient Information Leaflet[2].  

What is the typical dosage of simvastatin?

The usual starting dose is 10mg to 40mg once daily, in the evening. The maximum dose is 80mg daily (rarely used due to higher risk of side effects). Children take lower doses, adjusted by a specialist. Your dose will depend on why you need the medicine, your cholesterol levels, and other medicines you’re taking. Ask your doctor or pharmacist for advice if you’re unsure how much to take[1]. 

How do you take simvastatin?

Simvastatin should be taken once a day in the evening, because your body makes most of its cholesterol at night. It can be taken with or without food, but you should swallow tablets whole with a glass of water. Try and take it at the same time everyday[1]. 

Can you stop taking simvastatin?

Do not stop taking simvastatin without consulting your doctor or pharmacist. Stopping treatment can cause cholesterol levels to rise again. Your doctor may adjust the dose or offer an alternative if side effects are an issue[1]. 

What do you do if you take too much simvastatin?

Taking one extra dose of simvastatin is unlikely to cause harm. If you are concerned or have taken 2 or more extra doses, contact a pharmacist or doctor for advice[1]. 

What do you do if you forget to take simvastatin?

If you forget a dose, take the missed dose as soon as you remember. If it’s the next day, skip the missed dose and continue as usual. Do not take a double dose[1]. 

What medicines can’t you take with simvastatin?

Some medicines and substances can increase the risk of side effects, especially muscle-related ones. Avoid or use caution with[1]: 

• Certain antibiotics (e.g. clarithromycin, rifampicin, or fusidic acid) 

• Antifungals (e.g. itraconazole, fluconazole, or ketoconazole) 

• HIV and hepatitis C treatments 

• Warfarin for blood clots 

• Ciclosporin for psoriasis or rheumatoid arthritis 

• Danazol for endometriosis 

• Amiodarone  

• Blood pressure and heart medicine such as verapamil, diltiazem, and amlodipine 

• Colchicine for gout 

• Other cholesterol-lowering medicines (e.g. fibrates) 

• St John’s wort 

• Coenzyme Q10 supplements 

If you're need to take simvastatin at the same time as one of these medicines, your doctor may: 

• prescribe you a lower dose of simvastatin 

• Prescribe you a different statin 

• recommend that you stop taking simvastatin for a certain period 

Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2]. 

What are the side effects of simvastatin?

Common side effects (may affect up to 1 in 10 people) include[1]: 

• Headache 

• Nausea 

• Muscle pain or weakness 

• Constipation 

• Cold-like symptoms 

The rarer but more serious side effects include[1]: 

• Muscle weakness, tenderness or cramps 

• Skin reactions like erythema multiforme characterised by a skin rash with pink-red blotches on the palms of the hands and soles of the feet 

• Severe stomach pain as a sign of acute pancreatitis 

• Lung disease indicated by coughing, shortness of breath and unexplained weight loss 

• Myasthenia gravis symptoms of which include weakness in the arms or legs after activity, double vision, drooping eyelids and difficulty swallowing. 

• Liver problems (yellowing of the skin or eyes) 

• Severe allergic reactions (swelling, rash, difficulty breathing) 

You should contact your GP if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1]. 

Symptoms of anaphylaxis include:  

• Difficulty breathing  

• Tightness in throat and chest  

• Swelling of the tongue or throat  

• Feeling faint or dizzy  

• Blue/grey skin or lips  

• Loss of consciousness 

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice. 

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2].

Frequently asked questions about simvastatin

Can I drink alcohol while taking simvastatin? 
Yes, in moderation. Excessive alcohol can increase the risk of liver problems and can increase the chance of muscle side effects[1]. 

Can I eat grapefruit on simvastatin? 
No. Avoid grapefruit and grapefruit juice, as they can raise simvastatin levels[1]. 

Is simvastatin safe long-term? 
Yes, for most people, with regular check-ups and monitoring. It’s more effective if taken over a longer period[1]. 

For the official NHS guide to simvastatin, visit their website.