High blood pressure meds
Happy New Year, to all readers who normally rush to this page first, those readers who have made New Year resolutions, I wish you luck!
I want to look at some of the more popular anti-hypertension medicines or high blood pressure medication. High blood pressure is determined when someone gets a blood pressure reading of over 140/90.
Depending on your health status though or age, this cut off point may be lower, for example if you have diabetes or chronic kidney disease, HBP can be defined as 130/80 mmHg. HBP numbers also differ for children and teens.
So now you have been diagnosed as hypertensive and given a prescription. Depending on how your doctor wants to treat you, the prescription may have more than one item on it.
You go to your pharmacy and collect the medicines, go home, mope, stare at the meds in disbelief and then decide – “I ain’t taking none!” Then you go next month, to the pharmacy and collect your repeats that are “due” to you (must keep up appearances that you are taking them), take them home and park them next to the others. This would be funny if it was not true, but sadly it is more common than you think.
As a pharmacist it has always been my philosophy that people will take their medication, once they know what it is supposed to do. Hence this article, so let’s go:
Medicines for HBP can offer various solutions to the management of this disease. I like to portray the treatment of HBP as likened to reducing the volume or pressure of water coming out of a garden hose.
The typical garden hose is invariably attached to a tap and the pressure of water released is determined by either increasing the pressure on the actual hose by your finger or the amount of water turned on or off at the tap. Accordingly the medicines prescribed fall into performing one or both of these functions.
These drugs are the ones that work by turning the water off at the tap. Our blood pressure is a function of our blood volume or the amount of water in the blood. There are many classes of diuretics – those that work in the loop portion of the kidney, Thiazides, Carbonic Anhydrase Inhibitors, Potassium Sparing, Calcium Sparing, Osmotic or low ceiling diuretics.
An example of a Loop diuretic is Lasix. Interestingly the word Lasix was coined by combining the words will last six hours. Thiazides are the most common and can be found under the names of Bendrofluthiazide (Bezide); Hydrochlorothiazide and Indapamide (Natrilix).
Diuretics work by causing the kidneys to increase the amount of salts such as potassium and sodium that are filtered out of the blood and into the urine. When these salts are filtered out of the blood by the kidneys, water is also drawn alongside.
As diuretics increase the removal of salts from the blood, they also cause more water to be drawn out of the blood and into the urine.
Removing water from the blood decreases the volume of fluid circulating through the blood vessels. This subsequently decreases the pressure within the blood vessels. Diuretics are therefore used to lower high blood pressure.
Although Indapamide is classed as a diuretic, it also lowers blood pressure through a direct action on the blood vessels. Indapamide causes the blood vessels to widen, which reduces the pressure inside the blood vessels. This helps to lower blood pressure.
So we have seen how turning the tap off can affect blood pressure, let’s look at what moving that finger off the garden hose can do to improve your blood pressure. Obviously when you want the water pressure to be increased we press a finger onto the end of the hose, the water flies out under high pressure, but when we release that finger and the hose relaxes, the water flows out under normal or lower pressure.
The drugs that work in this way also come from different classes. We will mention a number of the popular ones.
* Beta Blockers ( Atenolol/Tenormin;Metoprolol/Lopressor)
* Calcium channel blockers (Verapamil; Amlodipine/Norvasc; Nifedipine)
* ACE inhibitors (Enalapril; Lisinopril; Ramipril/Tritace)
* Mixed Alpha and Beta blockers (Carvedilol/Coreg)
Beta-blockers work by slowing the heartbeat, which reduces the pressure of the blood flowing through the body.
Calcium channel blockers act by blocking the entry of calcium into muscle cells in artery walls. This also increases the size of the artery (moving the finger), thus causing a reduction in pressure.
ACE inhibitors and ARB’s work on similar lines, with the idea that reducing the kidneys ability to produce renin can affect blood pressure. Renin is implicated in the increasing of blood pressure. Bizarrely blacks in general have less renin, than whites, but in Barbados, this class of drug is the most prescribed!
The mixed Alpha and Beta-blockers will do what the Beta-blockers will do, but because of their Alpha-blocking action are used for mild to moderate congestive heart failure.
Many persons believe that they can predict HBP symptoms, but HBP is not called the silent killer for nothing, a stiff neck does not mean you have high blood pressure, and conversely not having the neck pain does not mean you don’t have HBP, If you have been diagnosed, please receive the information, process it, be thankful you are in Barbados, where medicine is publicly subsidised, utilise the experience and expertise of the health professionals around you and do what you can do to manage your hypertension.
Diet and exercise are extremely important to the management of HBP. Reducing your salt intake and doing moderate exercise will assist your doctor.