Types of Blood Pressure Medications
Prescribing an antihypertensive drug to a patient is tricky. This is because the mechanism of action of different antihypertensives is different.
An overall assessment of the patients’ health is made first. This includes:
- Weight, height and age of the person
- RFT- assessing kidney functions
- LFT- assessing liver functions
- Heart status of the patient
- Blood levels of cholesterol, trigycerides, LDL and HDL
Various BP Medicines Are Available
Antihypertensives are broadly grouped as follows:
Diuretics: They act by excreting out excess salt and water via the kidney. They include medicines like- chlorothiazide, furosemide and hydrochlorothiazide.
When they remove salt from the body, potassium (required for the muscles to contract) is also washed off along with sodium. So the patient may suffer side effects like- tiredness, leg cramps and weakness.
Sometimes doctors prefer prescribing Potassium-sparing diuretics like amiloride or spironolactone to overcome this side effect.
Also, diuretics interfere with blood sugar levels. So diabetic patients need to be extra cautious if taking them. Alterations in the dose of diabetic drug is often made.
Beta-blockers: They act straight on the blood pump of the body, that is the heart. They reduce the both, the force with which the blood is pumped and also the rate (frequency) of pumping blood. So the overall pressure of blood flowing in vessels is reduced. They include medicines like- atenolol, metoprolol, nadolol and betaxolol.
Patient may note the following side effects– cold peripheries (hands and feet), transient sad feelings (dysphoria), less sleep and fatigue. Also, this medicine is not given in pregnant women.
ACE inhibitors: There is a chemical called angiotensin produced by the walls of blood vessels of our body. When produced, this chemical constricts (narrows) the blood vessels, thereby increasing the blood pressure. Its’ production is controlled by the action of angiotensin-converting enzyme, which converts its’ inactive form into active form when required.
ACE inhibitors block the action of this enzyme preventing the conversion of inactive angiotensin into active one. Hence they reduce blood pressure. They include drugs like- lisinopril and moexipril.
Common side effects produced by this medication include skin rashes and hacking cough. This makes it difficult to prescribe it to patients with cough or any other respiratory problems.
Calcium channel blockers: Calcium is required by muscles of the heart and blood vessels to contract. This class of drugs acts by preventing calcium from entering the muscles, hence preventing their contractions. So the blood vessels remain in relaxed states and the blood pressure is reduced. They include – felodipine, nifedipine and nisoldipine.
Blood vessel dilators (vasodilators): They dilate or relax the muscular walls of blood vessels, lowering the pressure of blood flowing in them. They include names like- hydralazine hydrocholoride and minoxidil.
Blood pressure medications are often given in combinations. Never start a new medicine or alter the dose without consulting your doctor.