How Long Do Blood Pressure Medicines Stay In Your System?

Overview

Blood pressure medicines are used to treat individuals with high blood pressure (also known as hypertension). The duration of time that blood pressure medicines stay in your system depends on the drug you are prescribed, the dose you have taken and how often you take the medication (dose frequency). 

But do you know how blood pressure medications work and what the different types are?

Do you know how long do different blood pressure medications stay in your body?

Do you know when the best time to take blood pressure medication is?

This article will help you learn about blood pressure medication and be able to answer these difficult questions.

What are blood pressure medicines and what are they used for?

Blood pressure medicines are prescribed for people that have high blood pressure otherwise known as hypertension. 

Blood pressure readings are made using a blood pressure test. The first number is the systolic pressure. It refers to the force of the heart pumping blood around the body. The second number is diastolic pressure. This number refers to the resistance of blood flow in the blood vessels.¹

Normal blood pressure is defined as:²

• Between 90/60 mmHg and 120/80 mmHg

High blood pressure is defined as:

• 140/90 mmHg or higher

More information about high blood pressure can be found at the American Heart Association.

Hypertension or high blood pressure does not seem to have one specific cause. Instead, there are multiple lifestyle choices and other factors which increase your risk of developing high blood pressure.¹

These include:

• Being overweight
• A lack of exercise
• Having sleep problems / not getting enough sleep
• Relatives with high blood pressure
• African or Caribbean origins
• Smoking and drinking too much alcohol
• Being over the age of 65

Blood pressure medicines can control your blood pressure to prevent high pressure and hypertension. This is because high blood pressure puts extra strain on your heart and other organs and is a risk factor for strokes, coronary heart disease and many other cardiovascular disorders.⁷

Blood pressure medicines work in different ways depending on the type of blood pressure medication prescribed. 

These include:⁸ 

• Relaxing and widening the blood vessels reduce blood flow resistance and decrease blood pressure (ACE inhibitors, ARB inhibitors)
• Causing the body to excrete more water to decrease blood pressure and allow your salts to be at a healthy level in the body (Diuretics)
• Making your heart beat with less force (Beta Blockers)
• Blocking specific nerve activity to dilate the blood vessels (calcium channel blockers)

How long do blood pressure medications stay in your system? 

The duration of time that blood pressure medicines stay in your system depends on the drug you are prescribed, the dose you have taken and how often you take the medication (dose frequency). 

The most commonly prescribed blood pressure medication, lisinopril has a half-life of around 12 hours. The half-life refers to how long it takes your body to eliminate half the dose of the medication. This means it takes around 3 days before the drug is completely removed from the body.³

Another common blood pressure medication, amlodipine has a much longer half-life of 30-50 hours, hence it remains in your system for a longer time. For this medication to be completely removed from the body, it may take approximately 11.5 days, dependent on factors such as dosage and frequency of dosing.⁴

Medicines that are good for blood pressure

A few classes of medication may be prescribed for lowering blood pressure. Please note that you should not take these medications for blood pressure unless you are prescribed the drug. 

The drug you are prescribed may be based on your ethnicity, age and other variables that can dictate which blood pressure medication works best for you.¹ 

ACE inhibitors

A common example of an ACE inhibitor is lisinopril. They are used as blood pressure medications but are also prescribed for heart failure and kidney disease.³ African American individuals are more likely to be recommended ACE inhibitors as a blood pressure treatment. 

They work by inhibiting the formation of a hormone named angiotensin ll. They can do this by blocking the action of a key chemical necessary to make angiotensin ll, called angiotensin-converting enzyme. 

Angiotensin ll is responsible for:^3,5 

• Constricting blood vessels
• Increasing the volume of water reabsorbed into the blood from the kidneys
• Aldosterone release. This further increases water absorption into the blood

Therefore, blocking the action of angiotensin ll allows the blood vessels to relax and widen, reducing the pressure. Reducing the volume of water reabsorbed into the bloodstream also reduces blood pressure as there is less fluid to pump around the body.

Calcium channel blockers

A common example of a calcium channel blocker medication is amlodipine. Calcium channel blockers are used to reduce blood pressure but also are used in the treatment of angina. 

Calcium is necessary to allow your muscles and blood vessels to contract. Therefore blocking the release of calcium in the blood vessels keeps them dilated and widens the vessels to reduce blood pressure.⁶ 

If you take calcium channel blockers please refrain from drinking grapefruit juice. This can interact with the drug and cause side effects.¹

Beta blockers

This type of blood pressure medication is most widely known but is not often prescribed anymore. An example of a beta blocker for high blood pressure is atenolol. 

Not only can beta blockers be used for high blood pressure, but they are also commonly used medications in the treatment of heart failure and recurrent heart attacks. 

Beta-blockers work by blocking the release of stress hormones called adrenaline and noradrenaline. Their blockade causes the heart rate to decrease and reduces the force of the heart pumping blood around the body to reduce blood pressure.^1,9 

Diuretics

Diuretics are often known as ‘water pills’ and are often prescribed if an individual does not respond well to calcium channel blockers. A common example is indapamide. 

They work by increasing the amount of urine produced to flush out excess water and salts. They do this to reduce the volume of fluid carried in the blood and hence decrease the blood pressure.¹ 

Angiotensin 2 receptor blockers

These medications are sometimes called ARB inhibitors and work similarly to ACE inhibitors. They are usually prescribed when ACE inhibitors are not effective at treating the individual. A common example is candesartan. 

These drugs block a hormone called angiotensin-2 which is responsible for the constriction of the blood vessels and increasing blood pressure. By blocking the action of angiotensin-2, the blood vessels are widened and this prevents high blood pressure.¹⁰

Other

Instead of conventional medicine, some herbal remedies have some evidence to support their use in reducing blood pressure. An interesting article looks at if honey can reduce blood pressure. 

Please remember that herbal treatments do not have enough evidence to support their use as a treatment for high blood pressure and the medications you are prescribed are much more effective.

Side effects of blood pressure medicines

As with all medications, there are sometimes side effects caused by blood pressure medications. Generally, these are not experienced by the vast majority of individuals taking blood pressure medication.^1,7

General side effects may include:

• Dizziness
• Stomach issues
• Swelling in the legs/feet
• Headaches

There are more specific side effects for a specific blood pressure medication. Please read these carefully on the leaflet when you are prescribed a blood pressure drug.

How much blood pressure medicine can you take

If you are prescribed blood pressure medications, a dose will be indicated on the packaging of the medicine and the prescription slip. Please take care to follow the advised dose. Most blood pressure medications are taken once or twice daily.

If you have queries about your dosage, speak to your GP or a pharmacist.

When to stop taking blood pressure medicine

Please do not stop taking your blood pressure medicines unless you are advised to do so by your GP or a healthcare professional even if you feel better or your blood pressure returns to normal. 

If you wish to discontinue a blood pressure medicine, talk to your GP or a healthcare professional about why you want to stop taking your blood pressure medication and they will help you devise an action plan. You may need to reduce your dose slowly rather than stop taking the tablet completely. 

In the same way, if you have uncomfortable side effects from your blood pressure medication, you may simply need to swap to a different type of medicine. Not all drugs work for everyone in the same way and you can talk to your GP about your options.

Best time to take medicines for blood pressure

There is no set time that is recommended to take blood pressure medicines. The most important part about taking medicine is that you take your medication at the same time each day. Setting a timer on your phone can help ensure you do not forget to take your medicine. 

However, there is some evidence to suggest taking blood pressure medication before bed can be more beneficial than taking the medication in the morning. Although, this is only true for individuals that take blood pressure medication once per day. If you take blood pressure medication more than this, take your medication as your doctor recommends at regular intervals.¹¹

Summary

Blood pressure medicines help to control your blood pressure and treat hypertension. They are used to manage many heart conditions. 

• The amount of time blood pressure medications stay in your system depends on the medication prescribed, your dosage and your dose frequency
• Many different blood pressure medications can be prescribed according to variables including ethnicity, age and gender.
• It may be beneficial to take your blood pressure medications at night
• Do not stop taking your blood pressure medication without consulting your GP or a healthcare professional