The incidence of hypertension is increasing year by year. More and more medical experts recommend that patients with hypertension take long-acting antihypertensive drugs, thereby improving compliance, effectively maintaining normal blood pressure, and reducing the incidence of stroke and heart disease. At present, two long-acting antihypertensive drugs are most commonly used in clinical practice, one is amlodipine besylate tablets, and the other is nifedipine controlled release tablets. However, people often have some doubts about the mode of action, time of onset, and indications of these two kinds of “dipine” tablets, but simply think that both drugs can lower blood pressure.
Two “leveling” films are a pair of “twin brothers”
Amlodipine and nifedipine are on average dihydropyridine calcium antagonists, and their pharmacological effects are the same. Calcium antagonists block calcium channels on cardiac and vascular smooth muscle cells, prevent calcium ions from entering cells, thereby relaxing vascular smooth muscle, dilating peripheral arterioles, reducing peripheral vascular resistance, lowering blood pressure, delaying and reducing ventricular hypertrophy. Calcium antagonists can also reduce coronary heart flow, improve coronary blood flow, improve myocardial ischemia, and relieve angina. In addition, the two functions are similar, and are suitable for the treatment of hypertension, coronary heart disease, and chronic stable angina.
“Twin brothers” also have three different
The onset time is different. Because of the different chemical structures of the two, although they are the same as calcium antagonists, the rate of binding or dissociation with calcium channel receptors is different. Compared with nifedipine, amlodipine has a slow onset and a longer duration of action.
After oral administration of amlodipine, the plasma concentration reached a peak at 6 to 12 hours, the biological half-life was 35 to 50 hours, and continuous administration for 7 to 8 days reached a steady-state plasma concentration. Therefore, after the drug is administered to a hypertensive patient, the adjustment of the dosage of the individual should be started within 7 to 14 days.
After oral administration of nifedipine tablets, the therapeutic effect is rapid, 10 minutes, and the maximum effect is 1-2 hours, and the biological half-life is 4 to 5 hours. The nifedipine controlled release tablets are released by the membrane-controlled osmotic pump principle, so that the drug is released at a zero-order rate, and the drug is released at a constant rate within 24 hours. The peak concentration is reached 6 to 12 hours after oral administration, and the drug is generally administered continuously. The day can be smoothly reduced.
Different dosage forms of amlodipine are amlodipine besylate and amlodipine mesylate. Amlodipine besylate tablets are common tablets prepared by combining amlodipine with benzenesulfonic acid to form salts. It mainly exists in the form of ions in the blood. Because the ionic amlodipine is not easy to access the calcium channel, and the biodegradation in the liver is slow, it has a slower onset and a longer duration of action. Amlodipine besylate tablets can be taken from the middle if the blood pressure drops too low after the individual has been administered and appropriate reduction is required.
Nifedipine is a new controlled release preparation based on the principle of osmotic pump. It has slower onset, longer duration of action, higher bioavailability and more stable plasma drug concentration than sustained release. The rate of drug release is not affected by factors such as gastrointestinal motility, pH, etc. The inactive ingredients in the tablet pass through the gastrointestinal tract completely, and are discharged in the insoluble shell with feces, but cannot be taken apart.
Drug interactions with amlodipine besylate tablets in combination with simvastatin increased the plasma concentration of simvastatin. The elimination of nifedipine is closely related to the activity of liver drug enzymes. Therefore, drugs that inhibit or induce liver drug enzymes can affect the elimination process of the drug.
The specific medication for patients with hypertension needs to be diagnosed and symptomatic after diagnosis by a clinical specialist. Patients should not add or subtract drugs and doses themselves, so as to avoid adverse consequences on the body.