Please note that Dr Tom isn't familiar with all the circumstances in individual cases and can only deal with the points raised in general terms. Patients should always discuss any specific problems they have with their own doctors.

Readers' questions are answered as examples of general problems commonly met in practice. It is a good rule in medicine that only their own doctors know the patient well enough to pontificate on the case as there are often other factors unknown to strangers.

Is it dangerous to stop taking prescribed statins? My cholesterol levels have dramatically dropped but I hate taking pills for ever for familial cholesterolimia.

Name and address withheld

Yes. People with a persistently raised cholesterol, whatever the reason, have an increased incidence of atherosclerotic arterial disease. This leads inevitably to the gradual furring up of the arteries leading to the heart muscle, to the brain, to the genitalia (this is more obvious in men, than in women) to the kidneys and to the limbs. The amount that any artery is occluded will vary from person to person, but it is not always those people who have the greatest degree of occlusion (arterial blocking) who suffer from a thrombotic disaster.

Before a coronary thrombosis occurs the build up of the atheroma, the fatty material coating the inside of the artery, initially forms into plaques. When the plaque ruptures the debris that is discharged into the artery forms the basis of the thrombus that blocks an essential artery. Once this has happened the tissue is deprived of the life preserving oxygen and blood and tissue death (infarction) follows.

Of all the forms of a raised blood cholesterol that have been helped by the statins familial hyperlipidaemia has been helped the most. It has been a difficult one to treat. It may be necessary to take one of the stronger statins such as Crestor. In order that the dose of the statin may be reduced another drug Ezetrol (ezetimibe) is added to the cocktail. This has proved invaluable in the treatment of patients whose serum fats have not been controlled by statins accompanied by changes of lifestyle including diet, exercise and avoidance of tobacco.

When I started in medicine around fifty years ago a young colleague with familial hyperlipidaemia had a severe coronary thrombosis at the age of 32. Now this could have been prevented by using statins in childhood and adolescence associated with lifestyle changes.

Why are statins being prescribed for senior citizens, for whom higher cholesterol levels have a protective effect, and for women, for whom there is no therapeutic benefit, against a list of possible side effects too numerous to list here?

Peter Thomas, Neath

The facts don't support this proposition. It is a dangerous idea that hasn't sound medical backing and will be responsible for many deaths if it becomes widely believed. Medicine shouldn't be ageist. It is true that if someone with hypercholesteraemia only starts taking treatment in their late middle age the advantages that they might have received by starting earlier will not be as great as they might have been. I have been privileged to see the scans demonstrating the response to regular doses of statins in life preserving arteries that were becoming blocked. The patients were late middle aged or older. Helping to keep the arteries clear can't reverse damage, but it can help prevent further deterioration.

The so-called protective effect of hyperlipidaemia is based on a misunderstanding. The largest survey I know that was purported to demonstrate this was the one that studied the death rate in Paris hospitals when all elderly folk admitted to its wards as an emergency were studied. There was a slightly better outcome for those with a higher, rather than an average cholesterol. The effect of various compounding factors had not been taken into account. Cholesterol levels fall after surgical and medical disasters. My own fell to very low levels while I was in intensive care and for a short while afterwards. Women, too, benefit from statins, but the benefit may not be so marked, this is not because of the statins. It has been known for years that heart disease is less well diagnosed in women, treated later, and is more difficult to treat by invasive procedures. It would be terrible to deprive them of what benefits could be achieved by statins.

Statins may have some transitory side effects when they are first taken. The one or two rare and significant side effects can be diagnosed early if appropriate tests are carried out. The more trivial ones either wear off, or like insomnia for example, are avoided if the statin is taken in the morning. This may be slightly less effective, but a good night's sleep is assured. Medicine should never be either ageist of sexist.

Two years ago I was diagnosed with high blood pressure and cholesterol although the doctor said my good cholesterol levels were higher and bad cholesterol lower so she was not worried. After having all possible cardiac tests I was put on standard 40mg simvastatin and benzolfluormethazine to control the condition. After a year my blood pressure was still higher so I was prescribed Dilzem. I am 63 years old, as active as possible (had a right hip replacement). I feel fine and wonder whether I should still stay on the medication as my last blood pressure check up was satisfactory. What do you think about the combination of drugs I am taking? Should I change and try something else. I am worried about a long time use of these drugs and possible side effects. My doctor gives me a blood check-up once a year only.

Name and address withheld

The treatment you are having seems to be excellent but we don't comment on individual cases. What is essential treatment is to bring down the cholesterol levels to much lower levels than was initially believed. If there are other indications of heart disease, such as a high blood pressure, this becomes even more important. Although the emphasis on the treatment of hyperlipidaemia has been on lowering the low density lipoprotein cholesterol it is becoming increasingly apparent that it is important to boost the cardioprotective high density lipoprotein. The triglyeride levels should also be brought to an acceptable level. It is a nuisance to have to take drugs regularly but it is a small price to pay for living a longer life. People with other troubles, such as patients with diabetes, have to come to terms with this and so will all of us with high blood pressure and raised cholesterol.

I am a 51 year old male who had a heart attack last year at 50. No BP or cholesterol problems or anything to make me a likely victim, although I am about 10 kilos overweight, my diet was described as "excellent" by the dietician in hospital. I walk one hour every day. I was put on Simvastatin in hospital. Six months later I went back to my GP because my whole body ached. He took me off the statins and a month later I am fine. Should I go back now and be prescribed a different statin or stop indefinitely?

Nigel Murgatroyd, Chalfont St Giles

Vague aches and pains may be an initial aspect of statin treatment in a number of cases. The doctor is on the look out for those patients with specific muscle pains or weakness. These have to be carefully investigated so that the effects of a serious myopathy may be avoided. This may be achieved by monitoring the creatinine kinase levels. If these are significantly raised the drug must be discontinued. Sometimes changing a statin helps. In all cases it is helpful to begin with a very small dose and slowly tritrate it up until the desired effect is produced. The doctor should be aiming for the lowest effective dose. Statins are not indicated for people with significant renal or liver disease.

After taking Tamoxifen and Arimedex for five years for breast cancer, my cholesterol rose to over 9 and I was put on 20mg daily of simvastatin. This seems to be working, without serious side effects. But I read recently that long term use of statins can cause cancer. Am I balancing my risks correctly?

Theresa Stredder, London

There is no reliable evidence that I have ever seen of an association between statins and malignancy. Conversely to have a cholesterol of 9 is known to carry serious risks. You were following the correct advice well. Good luck. Keep it up.

Having claudication I was prescribed Pravastatin which removed the effect but which made me feel tired. Various US sites suggested taking Q10 as a supplement and tiredness went and I felt much better (and deteriorate fast without it). Biochemical arguments for the use of ubiquinone are very persuasive. Why isn't ubiquinone recommended or co-packaged?

Second question: I am male, 63, normal non fad diet plus large amounts of fruit and veg but no potato, had large RCC removed 2.5 years ago, new tumour growing slowly in remaining adrenal now l.s.56cm, identity not yet confirmed. Had to stop interferon because platelets sent below 40). Please explain relationship of statins with tumour growth.

Name withheld, Hayling Island

There is no sound evidence that Q10 is always successful. This doesn't mean to say that it won't help some people, and I am glad that it has proved useful to our reader. So far as I am aware there is no relationship of statins to carcinogenesis or the rate of tumour growth

I have been prescribed statins but after three days feel sick and generally unwell. After four attempts and a change from simvastatin to lipitor I have given up. With a reading of 6.2 LDL 1.6 (down from 7 with diet and exercise) is there anything else I can do? Would the symptoms eventually stop if I persisted with the statins? I take 6g of fish oil and 4g garlic daily as I have an enlarged left atrium and was told this would lead to AF in due couse. I take 8mg of candersartan and have BP of 125/65.

Derek Scoones, Whistable

This requires discussion with your doctor. Obviously it is undesirable to have an LDL of 6.2 especially if the reader has other evidence of cardiovascular problems. I always started my patients who had had side effects such as tiredness and vague aches and pains and had been feeling generally unwell with a very small dose of statins that I increased gradually. A patient may need to have several blood tests during the introduction of statins, but I can't remember one case in which we didn't succeed in enabling them to be symptom free. The only disaster I have ever seen with statins was in a doctor whose colleagues had failed to spot his problems.

I've been taking statins for nearly three years and have since had pains in my liver and pancreas area. Tests have shown that there is no damage to these but the pains continue. Is there an alternative to Lipitor? Also is there a website which shows a comparison between the cholesterol chart used by the UK, up to 8 and that by the rest of the world - e.g. up to 200?

Name and address withheld

Liver function tests need careful monitoring. Pancreatic disease is sometimes related to a raised cholesterol or triglyceride blood levels rather than to the statins taken to treat the hyperlipidaemia. These are all problems that need to be carefully sorted out with the reader's doctor. I have been looking for a chart that gives an easy comparison between the old British and American levels that I was brought up on and the European ones we adopted after the EU but have so far failed to find one.