Detailed Explanation of ACEI Drugs: Applicable Population and Management of Adverse Reactions

Which patients are suitable for ACEIs?

① Hypertension: Clinical studies have confirmed that this class of drugs can significantly lower blood pressure in patients with grade 1 and 2 essential hypertension. When used in combination with other antihypertensive drugs, it also has a good antihypertensive effect in patients with grade 3 hypertension.

② Hypertension complicated with heart failure: Large-scale international clinical trials have confirmed that this class of drugs can improve the survival rate of patients with heart failure, prolong their lifespan, and improve prognosis, making it the first-line drug for hypertension complicated with heart failure.

③ Left ventricular hypertrophy or vascular remodeling: This class of drugs can reverse left ventricular hypertrophy and vascular remodeling caused by hypertension. Its protective effect combines the blood pressure-lowering effect of angiotensin-converting enzyme inhibitors with the protective effect of non-hypertensive effects.

④ Renal insufficiency and diabetic nephropathy: This class of drugs has a protective effect on the kidneys and is the first-line treatment for patients with hypertension and renal insufficiency. When using it, start with a small dose and gradually increase the dose. When serum creatinine is less than 3.0 mg/dL, serum creatinine and potassium levels should be closely monitored; when serum creatinine is greater than 3.0 mg/dL, use should be discontinued.

Which patients are not suitable for ACEIs?

① Pregnant women;

② Patients with hyperkalemia;

③ Patients with bilateral renal artery stenosis.

What are the adverse reactions of ACEIs?

① Hypotension: It is generally believed that hypotension occurring with this class of drugs is related to the inhibition of the renin-angiotensin-aldosterone system. There is a risk of hypotension when using this class of drugs in cases of heart failure, severe hypertension (especially hyperreninemic hypertension), or in combination with diuretics.

② Cough: Approximately 29% of patients experience an irritating dry cough after taking this class of drugs (especially captopril), characterized by no sputum, worsening cough at night, accompanied by throat irritation symptoms such as dryness and itching. Most patients experience relief within about one week after discontinuation of the drug. ③ Acute renal failure: In patients with severe atherosclerosis, severe congestive heart failure, or bilateral renal artery stenosis, the use of these drugs can lead to reversible acute renal failure, especially when used in combination with diuretics. Therefore, for high-risk patients, serum creatinine levels should be monitored weekly during the first month of administration, and the drug should be discontinued immediately if serum creatinine levels rise.

④ Hyperkalemia: These drugs can increase serum potassium levels. Patients with chronic renal failure and those using potassium-sparing diuretics or potassium salts are prone to hyperkalemia. Therefore, serum potassium levels should be closely monitored in these patients when using these drugs.

⑤ Angioedema: The incidence rate is 0.1%. If accompanied by laryngeal edema, it can lead to death. Therefore, these drugs should be contraindicated in patients with a history of angioedema. ⑥ Allergic reactions: These usually occur in renal failure patients undergoing hemodialysis concurrently with this class of drugs. Allergic reactions typically occur within the first 2-3 minutes of dialysis. Mild cases may only involve itchy skin, while severe cases can lead to bronchospasm, hypotension, and collapse.

⑦ Other: Decreased sense of smell, leukopenia, proteinuria, itchy rashes, etc. Furthermore, pregnant women should not use this class of preparations, as studies have shown that these drugs can cross the placental barrier and cause fetal developmental disorders.

What should be done if coughing occurs while using angiotensin-converting enzyme inhibitors (ACEIs)?

① Rule out coughing caused by respiratory diseases.

② If there is no strict indication for using this class of drugs, consider switching to other antihypertensive drugs, such as calcium channel blockers or beta-blockers. ③ If the patient has diabetes, kidney damage or renal insufficiency (creatinine <3mg/dl), left ventricular hypertrophy, heart failure, etc., the importance of using this class of drugs should be emphasized, as the adverse cough reaction is less significant than its therapeutic effect. If the cough is mild, it is not necessary to discontinue the medication. Ferrous sulfate 0.3g can be taken daily, or sodium cromoglycate inhaler can be administered. If the cough still cannot be relieved, angiotensin II receptor antagonists (ARBs) should be switched promptly.

What are the adverse reactions of captopril and their prevention? What are the precautions for its use? Due to its definite efficacy and relatively low price, captopril has become a commonly used antihypertensive drug in clinical practice. In its widespread use, common adverse reactions should be taken seriously and prevented. Common adverse reactions and their prevention are as follows:

① Many patients experience an unbearable dry cough after taking captopril orally. This is because captopril inhibits both angiotensin-converting enzyme (ACE) and bradykinin, reducing bradykinin degradation and leading to bradykinin accumulation in the body. Bradykinin can dilate blood vessels, but it also stimulates bronchial smooth muscle, causing a dry cough. A persistent dry cough can be unbearable for patients. Doctors should note the following: First, patients should be informed beforehand to avoid misdiagnosis as a lung infection and subsequent treatment errors; second, the dry cough side effect should not be ignored simply because it may be caused by a respiratory illness, thus delaying treatment; third, medication changes should be considered. For ordinary hypertension patients, calcium channel blockers or beta-blockers may be considered, while patients with diabetes, kidney disease, left ventricular hypertrophy, or heart failure may use angiotensin II receptor blockers (ARBs), such as losartan or valsartan. Some literature reports that sodium cromoglycate inhalation or daily ferrous sulfate 0.3g may be tried for patients with dry cough.

② A small number of patients may experience pruritic rashes or pruritus without a rash, which will disappear after dose reduction or discontinuation. Antihistamines [such as loratadine (Claritin)] can also be used for short-term treatment.

The following points should also be noted during use:

① Because the dose-response curve of captopril is difficult to determine, it should be started with a small dose and gradually increased until a therapeutic dose is reached, then maintained.

② Captopril is contraindicated in patients with hypersensitivity to it, pregnant women, and breastfeeding women.

③ Avoid abrupt discontinuation of the drug during treatment. If the patient develops angioedema symptoms, such as swelling of the face, tongue, throat, limbs, difficulty swallowing or breathing, or hoarseness, the drug should be discontinued or symptomatic treatment should be given.

④ Captopril should be used with caution in patients with severely impaired renal function, autoimmune deficiencies, bone marrow suppression, hyperkalemia, or insufficient blood supply to the cerebral arteries or coronary arteries.

⑤ Follow-up examinations should be conducted during captopril use. a. White blood cell count and differential count, once every 2 weeks for the first 3 months; b. Proteinuria test, once every 4 weeks; c. Seek immediate medical attention if the patient experiences sore throat, fever, or decreased white blood cell count.

What are the characteristics of benazepril (Lotensin)?

Among angiotensin-converting enzyme inhibitors, benazepril (Lotensin) has a high affinity for kidney tissue. It is particularly suitable for treating diabetic patients with nephropathy, especially those with microalbuminuria and hypertension. It can lower blood pressure and reduce excessively high glomerular filtration rate, thus protecting kidney function. Some studies have shown that administering one tablet of Lotensin daily to patients with chronic glomerulonephritis for 3 months resulted in an average 34% reduction in 24-hour urinary protein. For patients with hypertension and hyperuricemia, thiazide diuretics should be avoided, while benazepril can lower serum uric acid levels. For patients with hypertension and left ventricular hypertrophy, in addition to controlling blood pressure, treatment should also focus on reversing left ventricular hypertrophy and improving aortic compliance; benazepril is very effective in this regard. This product can also significantly improve symptoms in patients with chronic heart failure. The usual dose is 10 mg once daily.