Diuretics for high blood pressure
Diuretics are also known as ‘water tablets’. This is because they have the effect of making excessive levels of salt and liquid leave your body in your urine. This is beneficial if you have high blood pressure because it helps to reduce the amount of water and salt in your blood.
If the level of salt in your blood is too high it can cause a build-up of excess fluid in your blood vessels. This can cause high blood pressure.
Diuretics are important if you have high blood pressure because they help to bring your blood pressure down. (They may also help to bring down the blood pressure in your blood vessels.) You should only need a fairly low dose of this type of drug to help treat high blood pressure levels.
Diuretics don’t usually cause side effects, unless you start taking a different type of medicine or take a higher dose than you have in the past. If you do have side effects these are likely to include low blood pressure when you change position – going from sitting to standing for instance. Needing to urinate more often than usual is another symptom. You may also find that you feel thirsty, dizzy or sick.
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Beta-blockers and high blood pressure
Beta-blockers work by reducing the workload of the heart. They do this by slowing down your heart rate, and by doing so, they also reduce your blood pressure. They tend to be used for people who have angina, people who have had a heart attack, and people who have arrhythmias or heart failure. Beta-blockers aren’t usually prescribed as a sole treatment to treat high blood pressure, but are usually prescribed alongside other drugs. These often include ACE inhibitors and/or calcium channel blockers.
How Alpha-blockers lower high blood pressure
Alpha-blockers reduce your blood pressure levels by stopping the hormone adrenaline from having a strong effect on your blood pressure. Adrenaline is often released when we are frightened, stressed or under pressure (both good and bad pressure).
When adrenaline is released into your blood stream it makes your blood vessels become narrower. This means that your blood pressure increases, and this puts greater strain on your heart.
These days alpha-blockers aren’t usually the first line of treatment for high blood pressure. They tend to be prescribed if other blood pressure medicines haven’t worked, and may be used alongside medicines such as ACE inhibitors (see below), or other blood-pressure lowering drugs.
How is high blood pressure diagnosed?
High blood pressure and ACE inhibitors
The full name for ACE inhibitors is Angiotensin-converting enzyme inhibitors. We all have a hormone known as angiotensin II that is created in our blood. This chemical can cause blood pressure problems because it can make our blood vessels narrower, so pushing up our blood pressure.
When there is less of this chemical in the blood stream our blood vessels relax, which means that our blood pressure goes down. Another important effect that happens when our blood vessels relax is that we have better blood flow to the heart. About 25% of the blood that is pumped from the heart each time it beats, goes through our kidneys. This keeps them working efficiently and helps to keep us healthy.
ACE Inhibitors are generally regarded as being able to control blood pressure to much the same level as ARBs (angiotensin blockers - see below). However, ACE Inhibitors are more likely to cause a dry cough as a side effect, compared to ARBs.
Examples: Captopril, Lisinopril, and Ramipril
How to monitor blood pressure
ARBs and your blood pressure
ARB stands for angiotensin receptor blockers, although these drugs are also known as angiotensin II receptor antagonists. We all have a hormone called angiotensin II, which has very strong constricting effects on our blood vessels. Narrowing our blood vessels increases blood pressure. Alongside this angiotensin II increases the amount of salt and water we retain in our bodies. This sends your blood pressure even higher.
ARBs combat the effects of angiotensin II by interfering with the way this hormone works. Angiotensin II affects AT1 receptors, found in the heart, blood vessels and kidneys in our bodies. By stopping this from happening, ARBs can reduce the level of your blood pressure, and stop Angiotensin II causing damage to vital organs, such as your heart.
Scientific evidence indicates that ACE Inhibitors and ARBs have similar results in controlling blood pressure. However ARBs are less likely to cause coughing as a side effect, and so may be your doctor’s first choice.
Systolic vs diastolic: what do the numbers mean?
Calcium channel blockers and high blood pressure
This name covers a group of medicines that help to treat conditions that affect your heart and blood vessels, Including high blood pressure. Calcium channel blockers (also known as CCBs) are generally used to treat high blood pressure, angina, and abnormal heart rhythms - also known as - arrhythmia, where your heart beat is irregular.
CCBs work by making your blood vessels wider. They do this by reducing the rate at which calcium migrates into your heart cells and into the walls of your blood vessels. The result is that your blood vessels become wider, and your heart can pump blood around your body more easily. As a result, your blood pressure comes down.
These drugs work well and safely in treating high blood pressure in any age group, including elderly and geriatric patients. In fact, the benefits of taking CCBs long term, include protection against stroke and heart attack.
You may have heard of atrial fibrillation, and ventricular tachycardia. These are conditions where your heart rhythm is too fast. As a group these are known as tachycardias.
(Bradycardias are conditions such as AV heart block and tachybrady syndrome, where the heart rhythms are too slow.)
Calcium channel blockers work effectively for people aged 55 years old or more, and for black people. However, they can cause some side effects, including swollen ankles, constipation and headaches.
You can increase your risk of experiencing these side effects if you drink grapefruit juice while you are taking these tablets.
Your guide to cardiovascular disease
Central agonists work on the brain to lower blood pressure
Central agonists (also known as central-acting agents and central alpha agonists) work in a different way to some other blood-pressure medications. They affect the blood vessels in the brain, relaxing them so that your blood pressure decreases.
Because they work in a different way to some other medications – by affecting the central nervous system instead of the cardiovascular system, which has the heart at its centre – these drugs may cause drowsiness. If they affect you in this way, talk to your doctor, and don’t drive.
Peripheral-acting adrenergic blockers/inhibitors
These drugs combat high blood pressure by interfering with the way neurotransmitters in the brain, work. By doing this they stop the brain’s smooth muscles from receiving instructions to tighten or constrict.
These drugs can cause some side-effects. These include heartburn, diarrhoea, and temporary dizziness on standing. If these side effects continue, talk to your doctor about whether these are the best drugs for you.
Direct Vasodilators were quite early blood pressure medicines. While they are still prescribed, they are not used as often these days because they have been largely replaced with newer blood pressure lowering drugs.
Your doctor may not prescribe this type of drug as a first choice for your treatment. According to Blood Pressure UK, hydralazine, one of the two direct vasodilators used in this country, along with minoxidil, may sometimes be prescribed for people who have developed heart failure. However it is unlikely to be prescribed if you have certain conditions, including heart disease, angina or diabetes.
Direct vasodilators work by making your blood vessels relax. This means that they allow more blood to pass through, which brings your blood pressure down. These drugs tend to act fairly quickly, and so may be used in an emergency situation.
Side effects of direct vasodilators include headaches, flushing, heart palpitations, swelling in your legs and feet, and an upset stomach.
Five new treatments for blood pressure
Direct Renin Inhibitors
Renin is an enzyme that sets off a reaction that can make our blood vessels narrow and cause our blood pressure to rise. Direct renin inhibitors prevent this from happening. As a result, our blood vessels relax, allowing blood to flow through them easily, helping to lower our blood pressure.
Your doctor may need to prescribe you a number of drugs to help keep your blood pressure down. They may also want to see you more often than normal, to make sure that your body is reacting well to these drugs and that your blood pressure is stable.
Bring down that blood pressure
Finding the right combination of high blood pressure medicine
Our blood pressure is affected by different factors and systems in our bodies. One medication may bring our blood pressure down, only to have another area of the body trigger a rise in blood pressure, using different bodily systems.
Causes of high blood pressure
Because we need to control high blood pressure in different ways, for different reasons, we may be prescribed more than one medicine to control our blood pressure.
So don’t be surprised if you discover that you are on a different medication to another family member, or friend. We’re all different, and may have different reasons why we have high blood pressure. Age, health problems and even our ethnic origins can affect how likely we are to develop high blood pressure. For example, people who come from African Caribbean or South Asian ancestry tend to be more likely to have high blood pressure.
Saga Health Insurance offers a range of health plans which provide cover if you develop high blood pressure (hypertension). If you've already been diagnosed they can often still cover your hypertension anyway, subject to some simple health questions and an additional premium. Find out more.
The blood pressure medication your doctor prescribes for you will depend on how old you are, whether you are of African-Caribbean ancestry, and whether you have certain existing health problems, like angina, for example.
Your doctor’s first choice of medication for you is likely to be an ACE inhibitor, or possibly another drug, an angiotensin receptor blocker, if you are aged under 55.
If you are older than 55, or have 100% African-Caribbean heritage, your doctor is likely to treat you with a calcium-channel blocker.
If these medicines alone aren’t tackling your blood pressure well enough, your doctor is likely to introduce another type of blood pressure medicine from a different group that will work in a different way. So if the calcium-channel blocker isn’t bringing your blood pressure down far enough, you GP may decide to also prescribe an ACE inhibitor for you to take as well.
Finding the best medication, or combination of medicines, may involve trying a few different ones until your medical team finds the best combination for you. This is likely to be a mix of two or three different drugs from different classes.
Once you have been prescribed medication to keep your blood pressure at a safe level, you must keep taking it. Do not stop taking this medicine, or change your dose, without talking to your GP first.
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