Medicine Watch: Blood Pressure Medication

Blood pressure is the measurement of the pressure of the blood in your arteries, as blood is pumped around your body by the heart. Your blood pressure will change throughout the day to meet your body's needs, as it is affected by many factors such as exercise and body position.

Your blood pressure is recorded as two numbers e.g. 120/80. The larger number, the systolic pressure, is a measure of the pressure in the arteries as the heart squeezes out the blood during a beat. The smaller number, the diastolic pressure, is a measure of the pressure in the arteries as the heart relaxes between beats.

High blood pressure, or hypertension, can lead to serious health problems such as heart disease and stroke. According to the American Heart Association here is a guide to the ranges of blood pressures.

Normal is defined as a systolic of less than 120 and a diastolic of less than 80.

Prehypertension is defined as a systolic of 120-139 or a diastolic of 80-89.

High Stage 1 is defined as a systolic of 140-159 or a diastolic of 90-99.

High Stage 2 is defined as a systolic of 160 or higher or a diastolic of 100 or higher.

Following is a list of commonly prescribed blood pressure medications, including how they work, side effects and what to look out for.

ACE Inhibitors

Angiotensin converting enzyme (ACE) inhibitors work by widening the blood vessels in your body which reduces the pressure in them and so makes it easier for your heart to pump oxygen around your body. The easier it is for your heart to work, the less likely you may do further damage to your heart and the easier it is for your heart to cope with any extra demands such as exercise.

Common side effects include dizziness when first starting the medication as well as when standing up too quickly, and a dry persistent cough.

Calcium Channel Blockers

Calcium channel blockers work in a similar way to the ACE inhibitors in that they widen the blood vessels in your body making it easier for the heart to work and reducing the pressure in the blood vessels. Calcium channel blockers do not affect the amount of calcium in your body. Some older calcium channel blockers also work by slowing down the heart rate.

Common side effects include dizziness when first starting the medication as well as when standing up too quickly. Sometimes swelling in the ankles can be experienced, if this occurs let your doctor know. Verapamil and diltiazem may also cause constipation.

Beta Blockers

Beta blockers also work to widen the blood vessels in your body, reducing the pressure in the blood vessels and making it easier for the heart to pump blood around the body. Beta blockers also affect the body's response to certain nerve impulses especially in the heart, reducing the heart's need for blood and oxygen and so making it easier for the heart to work.

Common side effects include dizziness when first starting the medication as well as when standing up too quickly. Beta blockers can also interfere with sleep and result in very vivid dreams, if this occurs, taking your dose in the morning may be a suitable option. Consult your doctor or pharmacist before making any changes to your medication regime.

Diuretics

Diuretics help reduce the amount of fluid retained in the body by increasing the amount of urine the body produces. The decreased amount of fluid flowing through your blood vessels then results in reduced pressure. Generally diuretics are taken in the first half of the day as taking them too close to bedtime can result in interrupted sleep due to getting up to urinate.

Common side effects include dizziness when first starting the medication as well as when standing up too quickly. Diuretics can also increase your blood sugar, so if you have diabetes and notice increased blood sugar levels consult your doctor.

Sources:

American Heart Association