Commonly prescribed diuretics are bendrofluazide, chlorothiazide, chlorthalidone, cyclopenthiazide, hydrochlorothiazide and indapamide.

That diuretics lower blood pressure was discovered by accident in the 1940s and, even today, it is not known how they work to reduce blood pressure.

It is claimed that diuretics prevent the cardiovascular illness caused by high blood pressure, such as stroke and heart failure, but the actual reduction in death rates appears to be only a modest 10 per cent (JAMA, 1997; 277: 739-45). The picture is further complicated by two recent pieces of evidence.

1. Low blood pressure as well as high blood pressure can lead to cardiovascular problems and premature death – and one cause of low blood pressure is diuretic drugs (Ann Intern Med, 2002; 136: 438-48).

2. Diuretics can have serious side-effects, such as cancer of the kidneys, which may further worsen death rates (Cardiovasc Drugs Ther, 2000; 14: 407-9).

Other side-effects of diuretics include impotence, dizziness on standing up (due to low blood pressure), blood disorders, skin reactions, gout, pancreatitis, and depletion of potassium, magnesium, coenzyme Q10 and zinc. There is also evidence that diuretics may be ‘harmful’ in people with coronary heart disease (J Cardiovasc Pharmacol, 1990; 16: 58-63).

Over 3 per cent of patients on diuretics find the accompanying side-effects intolerable (Pharmacotherapy, 2001; 21: 940-53).

The common side effects include hypotension, or low blood pressure, and so from that dizziness and headaches. Other likely reactions include diarrhea, cough, nausea and fatigue.

Another concern can be angioedema, where the tissues fill with fluids causing swelling. In most cases, the swelling goes down once the treatment is stopped, but emergency care needs to be given if the swelling is blocking the airways or affects the tongue or larynx.

Ironically, one reaction can be heart attack, the very thing the drug is supposed to prevent, although this is a rarer occurrence. Other less common reactions include abdominal pain, dry mouth, hepatitis, jaundice, mood swings, mental confusion, acute kidney failure and impotence.

People on the drug who suddenly develop a nonproductive cough or skin rash can be almost certain that it has been caused by the treatment, and the symptoms disappear once it is stopped.

Any cautious doctor should begin the treatment with just 2.5 mg daily which the manufacturer says is too little to have any beneficial effect, but should show any adverse reactions. The usual dose range is between 10 to 20 mg a day, and the maximum recommended amount is 40 mg. The dose should be increased over a two to four week period. Any treatment must begin in hospital.

Because of its possible effects on the kidneys, patients who already suffer kidney problems should naturally enough not take the drug, or any other ACE inhibitor. As studies have never been carried out on children or nursing mothers, neither group is advised to start treatment.

A:Some doctors will tell you that hypotension is a blessing and not a disease. When a patient presents with the collection of symptoms you mention, the tendency is either to call them hypoglycemic (suffering from low blood sugar) or hypotensive. If you do not have a history of heart problems and you are not taking drugs which can affect your blood pressure, and if you are not pregnant or diabetic, then finding the cause of low blood pressure can be difficult. So called neurally mediated hypotension (NMH) occurs after prolonged periods of standing. There is fatigue after modest exertion which can last 24 to 72 hours, and interferes with daily activities, as well as recurrent light headedness and fainting.

With NMH, the body has trouble regulating blood pressure, particularly when upright. There seems to be a misconnection between the brain and the nerves that control the blood pressure and heart rate. The reasons are not clear, but recent research at Johns Hopkins University in Baltimore, links NMH with other disorders such as chronic fatigue syndrome (CFS) and fibromyalgia syndrome (FMS) (JAMA, 1995; 274: 961-7). It is thought that post viral damage to the autonomic (involuntary) nervous system is a possible cause.

One way to diagnose NMH is with something called the tilt table test (TTT), where you lie strapped to a examination table which is slowly tilted to an upright position. Blood pressure and pulse rate are monitored, and a fall in blood pressure along with a sudden drop in pulse rate indicates a positive result. If your blood pressure does not fall during this phase of the test, you will be injected with a drug to raise the pulse rate.

If your blood pressure and pulse rate fall during this stage of the test, this is also considered a positive result.

Research on the TTT is thin on the ground. Many people faint during the test and some report that the medication makes them feel as if their hearts are about to burst open. Rather than subject an individual to this strenuous experience some doctors feel it is better to simply take a careful patient history.

Once diagnosed, there is no universal treatment for NMH. Simply advising more salt may be unhelpful and, for some, dangerous. There is no medication to cure hypotension, only to control symptoms, and what there is can cause distressing side effects.

One drug that has recently been approved for use is midodrine (ProAmatine). This drug needs to be prescribed with care since it can cause a marked elevation in supine (lying down) blood pressure (up to 200 mm Hg systolic). It should only be tried by those individuals whose lives are severely affected by hypotension and never on a just in case basis.

Another drug, Florinef (fludrocortisone) acts on the kidney to retain sodium, but it does so at the expense of losing more potassium into the urine. You will need to be on a high potassium diet while taking this drug. Side effects include headache, worsening of CFS, abdominal pain and depression.

Beta blockers such as Tenormin (atenolol) can also worsen CFS symptoms and existing asthma, cause depression and are also contraindicated in diabetics. Antiarrhythmics like Norpace (disopyramide) can also worsen CFS symptoms or existing glaucoma, as well as cause dry mouth, constipation or blurred vision.

Some find that even when on medication hypotension resurfaces or worsens when they are under stress.

Self help measures include, where practical, avoiding circumstances which might bring on symptoms, such as hot showers or standing too long. If you wish to increase your salt intake, but do not want to change the taste of your food, you can buy salt tablets.

Increasing your fluid intake, to at least two litres a day, is very important. Taking additional B12 may also assist in regulating blood pressure and nervous system response. Other supplements which help maintain a healthy nervous system include kelp, rich in B vitamins, carotene, potassium, iodine sodium, calcium, phosphorus and iron.

The herb broom (Sarothamnus scoparius) can help raise blood pressure. It can be used alone or in combination with hawthorn berries (Crataegus oxyacanthoides) to improve heart function.

The GP wants me to take Fosamax, but I’m already on Eltroxin and blood pressure tablets, including a diuretic. I don’t like taking those, but I’ve no choice.

Also, my oestrogen is very low, but I won’t touch HRT.- BC, Mallow, County Cork

A: Our view, as stated in earlier issues of WDDTY and our sister publication PROOF!, is that osteoporosis is a lifestyle disorder of modern times, and not an ‘oestrogen-deficiency’ disease that occurs as a matter of course in all women past the menopause.

Before you begin taking any drugs, it might be wise to examine your lifestyle to see what you are doing that might be contributing to the situation.

You might need to look no further than the thyroid drug you are taking. Eltroxin is a brand name of levothyroxine, a synthetic version of T4, a hormone produced by the thyroid gland. We assume that you are given this drug because you’ve had symptoms of hypothyroidism, or underactive thyroid.

As the metabolic regulator of the body, the thyroid produces hormones that have an effect on the amount of sex hormones produced and vice versa. So, if you are taking a thyroid replacement drug, this could be affecting the level of oestrogen in your body. (By the same token, if you take oestrogen replacement drugs such as HRT, it could increase your need for thyroid replacement.) According to the PDR, ‘. . . patients . .. . who are on thyroid replacement therapy may need to increase their thyroid dose if estrogens or estrogen-containing oral contraceptives are given.’

If you truly are suffering from low thyroid problems (and you might wish to get a second opinion on that, using the Barnes basal body temperature method of determining your true thyroid levels – see WDDTY, vol 12 no 9, Viewpoint), we recommend that you find an experienced professional who is willing to have you try natural thyroid supplements to see if that doesn’t cure the problem (see WDDTY, vol 12 no 10 for Dr Barry Peatfield-Durrant’s recommendations).

One touted benefit of the diuretic-type blood pressure drugs is that they supposedly slow the amount of calcium lost in the urine, and so may also slow bone loss (BMJ, 1991; 301: 1303-5). However, diuretics increase the loss of potassium, which may unbalance your system in a way that could exacerbate your problem.

You haven’t mentioned how high your blood pressure is, but if it isn’t too high, you might consider using natural methods (judicious exercise, dietary changes and vitamin supplements) to bring your blood pressure down. Also, see WDDTY, vol 9 no 10 for some suggestions on natural ways to beat osteoporosis.

A Hypotension, or low blood pressure, is not as common as hypertension – nor is it of as much concern to doctors. That’s probably why you hear so little about it. Hypertension is common because it is exacerbated by a sedentary lifestyle and obesity and, so, is increasing in prevalence, given our modern Western lifestyles. It is also a potentially life-threatening condition, being a risk factor for stroke and heart disease.

In contrast, low blood pressure has no long-term adverse effects and is, in fact, associated with a longer life expectancy. No wonder insurance companies like clients with low blood pressure – they continue paying into life insurance policies for longer.

However, hypotension can be an impediment as its main symptoms are fatigue, feeling faint and intermittent headaches. These are all the result of oxygen-carrying haemoglobin not being transported quickly enough around the body. It is dangerous only because sufferers could fall and injure themselves on fainting.

Feeling faint and dizzy is particularly noticeable when standing up quickly, which should be avoided. The effect is worsened by a hot bath, as the heat causes blood to migrate away from the organs and towards the periphery of the body.

One solution, according to panellist Dr Harald Gaier, is to supplement with organic iron. The liquid iron formula Floradix doesn’t come with the usual side-effects of standard iron tablets. If taken as indicated, it should provide your friend with enough iron to transport the required oxygen via her blood circulation more efficiently.

The headaches should cease too, as these familiar low-grade throbbings are simply the brain complaining that it isn’t getting enough oxygen.

I consulted my GP, who referred me to a ‘specialist’. After undergoing an EEG and MRI, I was told that they had found ‘something’ that was probably a brain tumour. I spent the next two years waiting to die.

I was given carbamazepine (Tegretol), but it has never been wholly effective. I have seizures once or twice a day and lose consciousness about once every seven to 10 days. It also has several unpleasant side-effects.

Two further scans, on newer equipment, revealed that the supposed brain tumour was probably old scar tissue.

Meanwhile, I noticed that my seizures were more likely to occur at certain times, such as:

* if I slept heavily in the night and was still sleepy – then 20 minutes after getting up
* if I stayed awake a long time into the night – then just as I dropped off to sleep
* between 12.30 and 13.00 – then just before lunch
* if not at that time – then just as I started to eat my lunch.

Thinking this might be linked to blood sugar or blood pressure, I recently bought a blood-sugar meter and a blood-pressure monitor. Since then, I have learned that:

* I have very low blood pressure most of the time, but it varies during the day
* the morning seizures are related to a swift drop in blood pressure
* I often have very low blood pressure and low blood sugar before a seizure
* rapid changes in blood pressure, e.g. due to emotions, can lead to a seizure.

I thought that I was alone in noticing this until I read on the Internet that the Manchester Heart Centre found that some patients diagnosed with epilepsy in fact had cardiac arrhythmias, and all had low blood pressure. Also, some cardiologists believe that difficulties with circulation may be the problem with up to 40 per cent of supposedly epileptic patients, but whose epilepsy is drug-resistant.

Having made more searches on the Net, I find that, in the US, it is recognised that low blood sugar and/or low blood pressure can trigger seizures.- Judy Tolman, Ludgershall, Buckinghamshire