This article is from "Nankai Sun Pharmacist", which is used for medical science popularization for reference. Can you take half a tablet of amlodipine?Can you take half a tablet of irbesartan hydrochlorothiazide?
Amlodipine is a widely used antihypertensive drug in clinical practice, classified as a calcium ion antagonist, mainly by inhibiting the transmembrane transport of calcium ions into vascular smooth muscle and myocardium, and its effect on vascular smooth muscle cells is stronger than that of cardiomyocytes, so that vascular smooth muscle relaxes, dilates peripheral arterial blood vessels, and reduces peripheral vascular resistance and blood pressure. In addition, amlodipine can also inhibit coronary spasm, restore coronary blood perfusion, reduce myocardial oxygen demand and relieve angina pectoris by reducing peripheral vascular resistance, and is mainly used in clinical practice for hypertension and coronary heart disease.
90% of amlodipine in the body needs to be metabolized by the liver into inactive metabolites, and the elderly have reduced liver function in most cases, and the clearance rate of amlodipine is reduced, causing the drug to accumulate in the body, which is easy to induce adverse reactions such as hypotension and arrhythmia, therefore, elderly patients and patients with liver insufficiency should be given a small dose2In addition, some patients with small stature, low body weight and frailty may have poor tolerance to the drug, which is prone to adverse reactions such as headache, tachycardia, dizziness, facial flushing, headache, etc., affecting medication compliance, therefore, for these patients, it should also be taken from a small dose25mg (half a tablet) to start taking amlodipine, some clinically some hypertensive patients with poor blood pressure control may need a combination of drugs, at this time can also be used25mg (half a tablet) of amlodipine combined with other antihypertensive drugs to reduce blood pressure synergistically.
At present, more than 90% of patients with clinical hypertension are essential hypertension, **unknown, unable to **, blood pressure stability is the result of drug control, if the blood pressure is stable, reduce the drug dose or stop the drug by yourself, blood pressure will soon be **, causing repeated fluctuations in blood pressure, and the damage to target organs such as heart, brain, and kidney is more serious. Therefore, if you take amlodipine, your blood pressure is controlled and stabilized for a long time (at least half a year to a year), you can gradually reduce the dose of the drug under the guidance of a doctor, still maintain a healthy lifestyle in the process of reducing the dose, pay attention to dietary adjustment and cooperate with appropriate exercise, and closely monitor the changes in blood pressure, and do not halve or stop the drug dose by yourself.
Irbesartan hydrochlorothiazide tablets are a single compound antihypertensive drug, including irbesartan and hydrochlorothiazide two first-line antihypertensive drugs, irbesartan belongs to angiotensin II receptor antagonists, by selectively binding to angiotensin II AT1 receptors, antagonizing the vasoconstrictor effect of angiotensin II, Reduce the level of aldosterone in the blood, reduce the retention of water and sodium and play a hypotensive effect, its antihypertensive effect is slow, but stable and long-lasting, and has a clear cardio-cerebrovascular and renal protective effect, but also can improve insulin resistance, long-term use can effectively reduce the risk of cardiovascular and cerebrovascular events in patients with hypertension, reduce microalbuminuria and proteinuria in patients with kidney disease or diabetes, especially suitable for patients with left ventricular hypertrophy, coronary heart disease, heart failure, atrial fibrillation, diabetic nephropathy, metabolic syndrome, microalbuminuria or proteinuria.
Hydrochlorothiazide is a medium-acting diuretic, mainly through natriuretic urination, reducing volume load, dilating peripheral blood vessels, reducing peripheral resistance and playing a hypotensive role, antihypertensive effect is fast, stable and long-lasting, long-term use can reduce the risk of stroke in hypertensive patients, especially suitable for elderly hypertension, simple systolic hypertension or patients with heart failure, and is also one of the basic drugs for refractory hypertension.
The combination of irbesartan and hydrochlorothiazide has a synergistic effect, which is beneficial to improve the antihypertensive effect. In addition, hydrochlorothiazide can also cause sympathetic nerve activation and affect the antihypertensive effect, and irbesartan acts on the renin-angiotensin-aldosterone system, which can inhibit sympathetic nerve overactivation and counteract this adverse factor. In addition, irbesartan can slightly increase the blood potassium level and can antagonize adverse reactions such as hypokalemia caused by long-term use of hydrochlorothiazide. Long-term use of hydrochlorothiazide is also easy to cause disorders of blood lipid, blood sugar and purine metabolism, and the combination of irbesartan can reduce the dosage of hydrochlorothiazide, thereby reducing the incidence of these adverse reactions.
Irbesartan hydrochlorothiazide tablets are available in two sizes, 150 mg 125mg and 300mg 125mg，150mg/12.5mg is 150mg of irbesartan and 12 of hydrochlorothiazide per tablet5mg，300mg/12.5mg is 300mg of irbesartan and 12 of hydrochlorothiazide per tablet5 mg, irbesartan dose range is 150-300 mg, hydrochlorothiazide is 125-25mg。Clinically, irbesartan hydrochlorothiazide is not recommended to reduce the dosage in 1 case, and half a tablet can be taken in 3 cases:
1.Abrupt taper is not recommended for patients with stable long-term blood pressure control, as it can easily cause blood pressure**, leading to fluctuations in blood pressure, which increase the risk of hypertension complications.
2.In the event of intolerable adverse reactions, such as dizziness, nausea, dry mouth, musculoskeletal injury, extreme fatigue, etc., the dose can be halved (150 mg 625 mg), the drug can be discontinued if necessary.
3.For patients with acute coronary syndrome or heart failure, irbesartan hydrochlorothiazide should be started at a low dose (150 mg 625 mg) to avoid first-pass hypotension and then gradually increase to a target dose that the patient can tolerate.
4.Erbesartan dilates glomerular efferent arterioles more than dilated glomerular afferent arterioles, decreases glomerular filtration pressure, decreases renal function, decreases glomerular filtration rate, and increases serum creatinine and serum potassium levels. Therefore, for patients with severe chronic kidney disease, the initial dose of irbesartan hydrochlorothiazide is halved (150 mg 6.).25 mg) and closely monitor changes in serum potassium, serum creatinine levels, and glomerular filtration rate.
5.Efficacy should be evaluated and serum potassium, creatinine, and glomerular filtration rate should be rechecked after 2 to 4 weeks of irbesartan hydrochlorothiazide** if elevated serum potassium is found ( 55 mmol L), if the serum creatinine increases by 30% or the glomerular filtration rate decreases by more than 30%, the dose of the drug should be reduced (150 mg 625 mg) and continue monitoring, discontinuing if necessary.