Guidelines for the Timing of Antihypertensive Medication Administration and Emergency Treatment

Should antihypertensive medications be taken before or after meals? This depends on the dosage form and duration of action of the medication.

① Sustained-release medications: Some short-acting medications, such as nifedipine (Adalat) and verapamil, require three doses daily. Improved dosage forms allow for slow release, thus extending the duration of action and transforming short-acting medications into long-acting ones. Currently, commonly used medications fall into three categories: a. Nifedipine controlled-release tablets (Baixintong) using laser perforation technology can release medication at a near-constant rate over 24 hours, unaffected by gastrointestinal motility and pH. One dose within 24 hours is sufficient, unaffected by food, and can be taken at the same time each day. However, it should not be chewed, crushed, or divided. b. Finadena tincture sustained-release tablets (Plendil) are unaffected by food but must be swallowed whole due to the coating layer. c. Sustained-release verapamil forms a sponge-like gel in the stomach, allowing the encapsulated drug to be slowly released and take effect. Therefore, it should be taken after meals. Taking it on an empty stomach will affect the drug release and cause stomach discomfort. Because it forms a gel on the surface of the stomach, unlike regular sustained-release tablets, it can be divided into half tablets for consumption.

② Long-acting drugs: including calcium channel blockers, ACEIs, ARBs, etc. Amlodipine (Norvasc), a calcium channel blocker, is well absorbed orally and is not affected by food; its efficacy is comparable whether taken on an empty stomach or after meals. Among ACEIs, quinapril (E-Heng) and perindopril (Yashida) are more effective when taken on an empty stomach; cilazapril (Yipingsu), fosinopril (Monopril), enalapril (Yuningding), and lisinopril (Jiecirui) can be taken on an empty stomach or with food without significantly affecting their antihypertensive effect. ARBs such as losartan (Cozaar) and valsartan (Diovan) have reduced absorption rates and slower absorption speeds when taken with food, but the overall antihypertensive effect is not significantly affected. To control morning hypertension and prevent cardiovascular events, it is generally recommended to take long-acting antihypertensive medication immediately upon waking.

③ Intermediate-acting medications: These medications are taken twice daily. Most take effect faster on an empty stomach than after meals. For example, beta-blockers like metoprolol (Betaloc) and atenolol can quickly relieve symptoms such as palpitations when taken on an empty stomach. However, elderly individuals and diabetic patients, due to poor neuroregulation, are more prone to orthostatic hypotension and other adverse reactions when taking medication on an empty stomach. It is recommended to determine the timing of medication based on blood pressure changes, or take it after meals or between meals. Intermediate-acting medications should be taken upon waking and at 2 PM; taking them before bedtime is generally not recommended. Diltiazem (Tianxin) sustained-release tablets and nifedipine sustained-release tablets, due to changes in dosage form that have transformed short-acting into intermediate-acting medications, have a thin outer shell and cannot be divided for consumption; taking them after meals is preferable.

④ Short-acting medications: Generally taken three times daily. Captopril absorption after oral administration is affected by food. When taken on an empty stomach, 60%–75% is absorbed, while after meals, only 30%–40% is absorbed. Therefore, it is recommended to take it one hour before meals. Nifedipine and clonidine are well absorbed orally and are generally not affected by food, but they take effect faster and have a more significant antihypertensive effect when taken on an empty stomach or sublingually.

What should a hypertensive patient do if their blood pressure suddenly rises at home? Hypertensive patients may experience a sudden increase in blood pressure due to factors such as emotional excitement, climate change, or endocrine disorders, leading to a sudden increase in blood pressure caused by severe constriction of small arteries, a significantly increased heart rate, and strengthened contractility. In addition, some patients may experience a series of symptoms such as excitement, dry mouth, sweating, headache, dizziness, tinnitus, nausea, vomiting, and blurred vision. When blood pressure exceeds 180–200/110–120 mmHg, it is called a "hypertensive emergency," and treatment should be sought immediately, regardless of whether there are no symptoms or only mild symptoms. Such high blood pressure, if not treated promptly, can develop into hypertensive encephalopathy, leading to loss of consciousness and even cerebral hemorrhage due to ruptured blood vessels. Therefore, upon discovering abnormal blood pressure accompanied by the above symptoms, immediate self-treatment to lower blood pressure is necessary. The method of self-treatment with medication is to take short-acting antihypertensive drugs orally. Five commonly used short-acting self-treatment drugs are: nifedipine, captopril, clonidine, furosemide, and furosemide. Nifedipine and captopril have rapid effects, taking effect within 30 minutes and reaching maximum efficacy within 1-2 hours. Nifedipine is commonly available in tablet form (10mg per tablet) and fast-acting capsule form (5mg per capsule), one tablet/capsule per dose; both have comparable antihypertensive effects. Captopril 20mg and clonidine 0.075mg generally take effect within 1 hour and reach maximum efficacy within 2 hours. If the patient is already taking nifedipine or captopril, the two drugs can be used together. If nifedipine is taken first, and blood pressure does not change significantly after 30 minutes to 1 hour, captopril or clonidine can be added. If the patient experiences nausea or vomiting, nifedipine or clonidine can be taken sublingually while continuously monitoring blood pressure. If the blood pressure does not decrease satisfactorily or symptoms worsen, an ambulance should be called immediately for emergency medical attention.

What constitutes a good, ideal antihypertensive drug? The 2005 "Guidelines for the Prevention and Treatment of Hypertension in China" requires that antihypertensive drugs be rationally selected based on the following criteria: definite efficacy, few side effects, long duration of blood pressure reduction, convenient administration, and reasonable price. Therefore, we can say that there is no single class of antihypertensive drugs that can be considered the best or most ideal. Different patients may be more suited to one or more antihypertensive drugs. For example, elderly patients with isolated systolic hypertension are more suitable for calcium channel blockers, while patients with diabetes are more suitable for ACE inhibitors or ARBs. For patients experiencing dry cough while using ACEIs, if their financial situation allows, they can switch to ARBs. If their financial situation is limited and there are no strict indications for using ACE inhibitors, they can consider switching to calcium channel blockers or beta-blockers. Therefore, the choice of antihypertensive drugs should be based on the patient's specific condition, the drug's efficacy, and the price. Choose the right one, not the most expensive one. The best and most ideal drug is the one that suits you in all aspects. 78. How should hypertensive patients use aspirin correctly? Most hypertensive patients should use aspirin, but not all hypertensive patients need or can use it.

There are three main categories of hypertensive patients who should use aspirin:

① Hypertensive patients over 50 years of age;

② Hypertensive patients under 50 years of age with any of the following risk factors or diseases: atherosclerosis, smoking, obesity, diabetes, family history of coronary heart disease, or dyslipidemia;

③ Patients with thrombotic diseases, such as coronary heart disease, cerebral infarction, or peripheral artery disease. Aspirin works by inhibiting the function of platelets in the blood, thus achieving an anticoagulant effect. This inhibition is irreversible. Approximately one-tenth of the platelets in the human body are newly generated and functional each day. Inhibiting these newly generated and functional platelets, preventing them from clotting, achieves an anticoagulant effect. Therefore, taking aspirin once a day is sufficient. Currently, 75-150 mg of aspirin daily is generally considered the most effective. The effectiveness of doses below 75 mg is uncertain, while doses above 325 mg increase side effects and reduce efficacy. Therefore, my country stipulates that the optimal long-term dose of aspirin is 75-150 mg daily.

Which hypertensive patients can take aspirin?

① Those with well-controlled blood pressure: Hypertensive patients should take aspirin only if their blood pressure is well-controlled. Data shows that for people with high blood pressure, taking aspirin not only does not reduce the risk of heart disease and stroke, but may also cause bleeding. ① For individuals with systolic blood pressure below 135 mmHg, taking aspirin can reduce the incidence of cardiovascular and cerebrovascular diseases by 45%, while the risk of coronary heart disease is not reduced in those with systolic blood pressure above 145 mmHg.

② Hypertension accompanied by symptoms: Aspirin should be taken by individuals with hypertension accompanied by dyslipidemia, obesity, coronary heart disease and their family history, or those with a 10-year cardiovascular disease risk greater than 20% based on comprehensive assessment, or those with elevated blood viscosity in laboratory tests, as well as those who smoke and have hypertension. In addition, men over 40 years of age, postmenopausal women, and young people with coronary heart disease risk factors should also consider aspirin treatment due to their increased risk of heart disease.

③ Myocardial infarction and cerebral infarction: Patients who have experienced these diseases should take aspirin to inhibit platelet function, prevent thrombosis, and prevent recurrence in order to prevent recurrence. ④ Patients with diabetes: Type 2 diabetic patients with cardiovascular disease have increased levels of thrombocytidine in their bodies. Thrombocytidine is a powerful vasoconstrictor and platelet aggregator. Aspirin can inhibit cyclooxygenase, limit the formation of thrombocytidine, and reduce platelet aggregation. This can not only reduce various complications caused by vascular embolism in diabetes, but also lower insulin, blood glucose, and triglyceride levels with continuous administration. Therefore, these patients can continue to use aspirin in combination.