Product Overview
[Drug Name]
Generic Name: Nifedipine Sustained-Release Tablets (II)
Trade Name: GaoSu Nifedipine Sustained-Release Tablets (II) 20mg*30 Tablets (Bottle)
Pinyin Code: GaoSu XiaoBenDiPingHuanShiPian(II) 20mg*30 Tablets (PingZhuang)
[Main Ingredient]
Nifedipine.
[Indications/Main Functions]
Indicated for: 1. Chronic stable angina (exertional angina); 2. Vasospastic angina (Prinzmetal's angina, variant angina); 3. Essential hypertension.
[Precautions]
1. Patients with severe hypotension (systolic blood pressure below 90 mmHg) and decompensated heart failure should only take this product after consulting a physician and under special monitoring. This applies even if the patient has only experienced these conditions in the past. Although nifedipine-induced hypotension in patients with angina is generally moderate and well-tolerated, it can occasionally cause an excessive drop in blood pressure that patients cannot tolerate. This phenomenon often occurs during drug initiation, dose increases, and concomitant beta-blocker use. There have been reports of patients receiving nifedipine and a beta-blocker experiencing severe hypotension or requiring intravenous volume expansion during coronary artery bypass surgery when high-dose fentanyl is administered. This drug interaction may occur with the combined use of nifedipine and a beta-blocker, as well as with nifedipine alone, low-dose fentanyl, other surgical procedures, or anesthetics. Physicians should be aware of this issue when high-dose fentanyl is administered to patients receiving nifedipine. If possible, nifedipine should be washed out of the system before surgery (at least 36 hours). Patients taking nifedipine for hypertension or angina may experience an increase in angina or myocardial infarction. Rarely, the frequency, duration, or severity of episodes may be increased when nifedipine is initiated or the dose is increased, particularly in patients with severe occlusive coronary artery disease. However, the mechanism is unclear. 3. Gradually reducing the beta-blocker dosage is preferable to abruptly stopping it before taking nifedipine. Patients who have recently discontinued beta-blockers may experience a withdrawal syndrome with increased angina, which may be related to increased sensitivity to catecholamines. Rarely, heart failure may develop after starting nifedipine in patients receiving beta-blocker therapy, and patients with aortic stenosis are at greater risk. 4. Because nifedipine breakdown is delayed in patients with impaired liver function, physicians should closely monitor the course of nifedipine use. If necessary, the dosage should be reduced. 5. A low dosage should be used for patients with severe cerebral circulation (cerebrovascular disease). 6. Dialysis patients with malignant hypertension and hypovolemia should be aware of the potential for a significant decrease in blood pressure due to vasodilation. 7. Due to individual differences in drug response, this product may affect the ability of individuals engaged in driving, operating machinery, or without appropriate safety precautions. This effect may primarily occur during the initial treatment phase, during dose increases, when changing medications, or when consuming alcohol. Therefore, patients engaged in the above-mentioned occupations require regular clinical follow-up while receiving this drug. 8. If the dose of this drug is too low or a dose is missed, do not take a double dose at once. Take the next normal dose according to the prescribed dosing interval.
[Drug Interactions]
1. Hypersensitivity to nifedipine or other ingredients in this drug. 2. History of cardiogenic shock. 3. Severe aortic stenosis. 4. Unstable angina. 5. Recent myocardial infarction (within the last 4 weeks). 6. Patients currently taking rifampicin. 7. Pregnant women.
[Specifications]
20mg*30 tablets (bottle)
[Dosage and Administration]
1. Chronic stable angina: Take one 20mg tablet twice daily. 2. Vasospastic angina: Take one 20mg tablet twice daily. The standard dose is one 20mg tablet twice daily; the dose can be increased to two 40mg tablets twice daily. 3. Essential hypertension: Take one 20 mg tablet twice daily. The standard dose is one 20 mg tablet twice daily; the dose can be increased to two 40 mg tablets twice daily.
[Adverse Reactions]
1. The following symptoms are common, especially at the beginning of treatment, but are usually transient: headache, flushing of the face or skin accompanied by a feeling of warmth (erythema), and redness, swelling, and pain in the upper and lower extremities (erythema). Occasionally, there may be a rapid pulse (tachycardia), palpitations, and lower extremity edema due to vasodilation. Dizziness and fatigue may occur occasionally. Numbness and tingling in the upper and lower extremities and a drop in blood pressure below normal (hypotension) have also been reported. 2. Gastrointestinal disturbances (e.g., nausea, abdominal distension, and diarrhea) are rare. Skin allergic reactions (e.g., pruritus, urticaria, and rash) are rare. Rare abnormalities in the blood test (e.g., decreased red blood cell, white blood cell, and platelet counts, and skin and mucous membrane bleeding due to thrombocytopenia) are rare. 3. In patients receiving long-term treatment, gingival hyperplasia is rare and disappears spontaneously after discontinuation of the drug. 4. Liver function abnormalities (intrahepatic cholestasis, elevated transaminases), blood cell counts (agranulocytosis), skin and mucous membrane hemorrhages (purpura), exfoliative dermatitis, photodermatitis, and acute systemic allergic reactions (such as skin and mucous membrane swelling, laryngeal edema, bronchial muscle spasms, including fatal respiratory distress) are extremely rare and disappear after discontinuation of the drug. 5. Breast swelling (gynecomastia) is rare, especially in elderly male patients receiving long-term treatment with this product. Symptoms disappear spontaneously after discontinuation of the drug. Rarely, elevated blood sugar is rare. This reaction usually occurs in patients with diabetes. 6. In some patients taking high doses, muscle pain, finger tremors, and mild transient visual changes may occur. 7. At the beginning of treatment, patients may rarely experience a brief loss of consciousness (syncope) due to low blood pressure. Angina attacks may rarely occur in patients at the beginning of treatment; the frequency, duration, and severity of angina attacks may be increased in patients with a history of angina. 8. Patients with renal impairment may experience transient worsening of renal function while receiving this drug. Particular attention should be paid to dialysis patients with hypertension and hypovolemia, as vasodilation may significantly lower blood pressure. 9. Urine output may increase during the first week of treatment. 10. If patients experience any adverse reactions not described in this package insert during treatment, please consult a physician immediately.
[Contraindications]
1. Hypersensitivity to nifedipine or other ingredients in this drug. 2. Previous cardiogenic shock. 3. Severe aortic stenosis. 4. Unstable angina. 5. Recent myocardial infarction (within the past 4 weeks). 6. Patients currently taking rifampicin. 7. Pregnant women.
