There are several categories of medications used to treat high blood pressure. Each works differently to lower blood pressure and has its own advantages and potential side effects.
ACE inhibitors
These medications block the production of angiotensin II, a hormone that narrows blood vessels and raises blood pressure. ACE inhibitors can help relax blood vessels and improve blood flow, leading to lower blood pressure. Common examples include lisinopril, enalapril, and ramipril. Some common side effects of ACE inhibitors include:
- Dry cough: About 10-20% of patients taking ACE inhibitors develop a dry cough. This side effect usually goes away once the medication is discontinued.
- Dizziness: ACE inhibitors can cause a drop in blood pressure, which can result in dizziness, especially when getting up from a sitting or lying position.
- Headaches: Some patients may experience headaches while taking ACE inhibitors, although this side effect is relatively uncommon.
- Fatigue: ACE inhibitors can cause fatigue or weakness in some patients.
- Rash: In rare cases, ACE inhibitors can cause a rash or other skin reactions.
- Hyperkalemia: ACE inhibitors can increase potassium levels in the blood, which can cause symptoms such as muscle weakness, irregular heartbeat, and nausea.
Angiotensin II receptor blockers (ARBs)
These medications work by blocking the effects of angiotensin II on blood vessels. This can help lower blood pressure and improve blood flow. ARBs include losartan, valsartan, and olmesartan. The potential side effects of ARBs are similar to those of ACE inhibitors.
- Dizziness: ARBs can cause a drop in blood pressure, which can lead to dizziness or lightheadedness, especially when standing up from a sitting or lying position.
- Fatigue: Some people may experience fatigue or weakness while taking ARBs.
- Headache: Headaches can occur as a side effect of ARBs, although this is rare.
- Nausea and vomiting: Some people may experience nausea or vomiting while taking ARBs.
- Diarrhea: ARBs can cause diarrhea in some individuals.
- Hyperkalemia: ARBs can raise the level of potassium in the blood, which can lead to hyperkalemia in some people. This can cause symptoms such as weakness, nausea, and heart palpitations.
- Allergic reactions: In rare cases, ARBs can cause an allergic reaction, which can lead to symptoms such as rash, itching, and difficulty breathing.
Calcium channel blockers
These medications block calcium from entering the muscle cells in the walls of blood vessels, causing the vessels to relax and widen. This leads to lower blood pressure and improved blood flow. Common calcium channel blockers include amlodipine, verapamil, and diltiazem. Side effects of calcium channel blockers may include the following:
- Dizziness: CCBs can cause dizziness or lightheadedness. This is more common when starting the medication or increasing the dose.
- Headache: Headaches are a common side effect of CCBs, but they usually go away as the body adjusts to the medication.
- Flushing: Some patients may experience flushing, or a warm sensation in the face or neck.
- Swelling: CCBs can cause swelling in the feet, ankles, or legs. This is more common in older patients or those with existing heart or kidney problems.
- Constipation: CCBs can cause constipation or other digestive issues, such as nausea or abdominal pain.
- Fatigue: Some patients may feel tired or fatigued while taking CCBs, especially when first starting the medication.
- Less common side effects of CCBs may include irregular heartbeat, shortness of breath, or fainting. Patients should talk to their healthcare provider if they experience any concerning symptoms while taking CCBs.
Diuretics
Also known as water pills, diuretics help remove excess water and sodium from the body through urine, which can reduce blood volume and lower blood pressure. Common examples include hydrochlorothiazide, furosemide, and spironolactone. The most common side effect of diuretics is frequent urination. Other potential side effects include:
- Dehydration: Since diuretics increase urination, they can also lead to dehydration. Signs of dehydration include dry mouth, thirst, and fatigue.
- Low potassium levels: Diuretics can cause low levels of potassium in the body, which can lead to muscle weakness, cramping, and an irregular heartbeat.
- Low sodium levels: In some cases, diuretics can cause low levels of sodium in the body, which can cause nausea, headaches, and confusion.
- Dizziness and lightheadedness: Diuretics can cause a drop in blood pressure, which can lead to dizziness and lightheadedness.
- Erectile dysfunction: In men, diuretics may cause erectile dysfunction
These medications block the effects of adrenaline on the heart and blood vessels, leading to lower blood pressure and slower heart rate. Beta blockers include metoprolol, atenolol, and propranolol. Potential side effects of beta blockers include fatigue, dizziness, and low blood pressure. Some common side effects of beta blockers include:
- Fatigue and weakness: Beta blockers may cause fatigue and weakness in some people, which can make it difficult to carry out daily activities.
- Dizziness and lightheadedness: Beta blockers can cause a drop in blood pressure, which may result in dizziness or lightheadedness.
- Cold hands and feet: Beta blockers can cause constriction of blood vessels, which can lead to decreased blood flow to the extremities, resulting in cold hands and feet.
- Sleep disturbances: Beta blockers may cause sleep disturbances, such as insomnia or vivid dreams.
- Erectile dysfunction: Beta blockers may cause sexual dysfunction in some men, including erectile dysfunction.
- Depression: Some people may experience symptoms of depression while taking beta blockers.
- Breathing difficulties: Beta blockers may cause breathing difficulties in people with asthma or chronic obstructive pulmonary disease (COPD).
- Nausea and vomiting: Beta blockers may cause nausea and vomiting in some people.
Renin inhibitors
These medications block the action of renin, an enzyme produced by the kidneys that helps regulate blood pressure. Aliskiren is the only medication in this category currently available in the United States. Potential side effects of renin inhibitors include cough, diarrhea, and low blood pressure. While generally well-tolerated, there are some possible side effects:
- Hyperkalemia (high potassium levels in the blood): This is a potential side effect of renin inhibitors, particularly in patients with pre-existing kidney disease or those taking other medications that can increase potassium levels. The inhibition of renin can lead to decreased aldosterone levels, which can increase potassium retention in the body.
- Angioedema: This is a rare but serious side effect of renin inhibitors. Angioedema is a swelling of the face, lips, tongue, or throat that can obstruct the airway and cause difficulty breathing. This side effect occurs due to the inhibition of the renin-angiotensin-aldosterone system, which can lead to an increase in bradykinin levels in the body.
- Hypotension: Renin inhibitors can cause a drop in blood pressure, particularly in patients who are already on blood pressure-lowering medications. This can lead to symptoms such as dizziness and lightheadedness.
- Cough: Like ACE inhibitors, renin inhibitors can cause a dry, persistent cough in some patients. This side effect is thought to occur due to the accumulation of bradykinin in the lungs.
- Diarrhea: Some patients may experience diarrhea while taking renin inhibitors. The reason for this is not well understood, but it may be related to the medication’s effects on the digestive system
It’s important to note that everyone’s response to blood pressure medication can vary, and some people may need to try different medications or combinations of medications to achieve optimal blood pressure control. It’s also important to work closely with qualified healthcare providers to closely monitor blood pressure and any potential side effects of medication.
