Stroke: Why skipping blood pressure medicines is dangerous

Daily intake of blood pressure medications drugs is absolutely necessary in people with hypertension. Doctors have long known that high blood pressure cannot be known from the face and adherence to medication is important to prevent stroke, reports Sade Oguntola.

Doctors have long known that high blood pressure, or hypertension, is among the most important risk factors for stroke. Now a new study has found that patients with hypertension who don't take their prescribed blood pressure-lowering medications may be placing themselves at risk for both fatal and nonfatal strokes.


Scientist in a large Finnish study found that patients who skip their blood pressure medications were more likely than those who consistently took their medications to die from stroke, reinforcing the need for individuals with high blood pressure to make every effort to adhere to their treatment.

A stroke, sometimes called a "brain attack," occurs when blood flow to an area in the brain is cut off. As a result, the brain cells, deprived of the oxygen and glucose needed to survive, die. If not caught early, permanent brain damage or death can result.

Hypertension is defined as having systolic blood pressure of at least 140 millimetres of mercury (mm Hg) and diastolic blood pressure of at least 90 mm Hg. (Systolic and diastolic are the top and bottom numbers, respectively, in a blood-pressure reading.)

Minister of Health, Professor Onyebuchi Chukwu on the occasion to mark the World Health Day in Abuja, put the prevalence of hypertension, the biggest single risk factors for heart disease and stroke, at 20 per cent.

In this study published in the European Heart Journal, the scientists examined data from Finnish national registries covering prescriptions, hospitalisations, and deaths stretching from 1995 through 2007.

The analysis included 73,527 individuals 30 and older who required continuous antihypertensive therapy for a diagnosis of hypertension and who were free from stroke or cardiovascular disease at baseline. During follow-up, 2,144 patients died from stroke and another 24,560 were hospitalised for stroke.

Patients who were not adherent to treatment had increased odds of both stroke and hospitalisation for stroke at multiple time points after adjustment for age, sex, length of antihypertensive therapy, education, household income, diabetes, and history of cancer.

Why does poor adherence to blood pressure medications predispose to stroke? Dr Mayowa Owolabi, a consultant neurologist, University College Hospital (UCH), Ibadan, Oyo State explained that poorly controlled blood pressure was a major reason some people end up with stroke.

In Nigeria, every six minutes, one Nigerian develops stroke. In Africa, the incidence of stroke is as high as 316 per 100,000 population per annum. Stroke occurs for reasons such as undiagnosed, untreated or poorly treated hypertension, diabetes, cigarette smoking, excessive alcohol consumption, diet rich in cholesterol, sedentary living and heart problems.

Unfortunately, Dr Owolabi stated that "the main reason adults are admitted to the medical ward of the University College Hospital (UCH), Ibadan, Oyo State is stroke,"

However, the expert explained that persistently uncontrolled blood pressure, which could arise from non compliance to prescribed blood pressure-lowering medications, could overtime contribute to the hardening of the large arteries. This, in turn, can lead to blockage of small blood vessels in the brain.

Narrowing or blockage of the blood vessels is a hallmark of cardiovascular diseases such as heart attack, stroke, and poor circulation in the legs — which can cause pain and even gangrene.

Dr Owolabi declared that the higher the blood pressure the more the risk of stroke occurring, adding that sometimes high blood pressure can also lead to weakening of the blood vessels in the brain, causing them to balloon and burst.

However, up to 80 per cent of all strokes are preventable. "Many risk factors for stroke such as an irregular heart rhythm, uncontrolled diabetes, high total cholesterol, high salt intake, being overweight, smoking and alcohol can be controlled before they cause stroke," he said.

For instance, people that smoke and have high blood pressure are 18 times more likely to have a stroke than someone the same age that doesn't smoke and has normal blood pressure.

He added that people at risk for stroke and heart attack may also be treated with aspirin or similar medications, which can prevent blood clots from forming.

Moreover Dr Owolabi said medicines can help control high blood pressure but do not cure it, adding that usually blood pressure medicines need to be taken long-term.

Given that individuals based on the way they feel cannot know whether or not their blood pressure is high, he said its regular check with Sphygmomanometer is important.

A previous study had suggested that people with occasionally high blood pressure are more at risk of stroke than those with consistently high readings. Current guidelines focus on measuring average blood pressure levels to spot and prevent the chance of a stroke.

The researchers looked at the variability in blood pressure readings at doctors' checks. They found those with fluctuating readings at different GP visits had the greatest risk of future stroke regardless of what their average blood pressure reading was.

Warning signs of a stroke include sudden weakness of the face, arm, or leg, most on one side of the body; sudden confusion, trouble speaking or understanding; sudden trouble seeing in one or both eyes; sudden trouble walking, dizziness, loss, of balance or coordination and sudden severe headache with no known cause.

Culled from the Nigerian Tribune