Product Overview
[Drug name]
Generic name: Doxazosin mesylate sustained-release tablets
Trade name: KeDuoHua Doxazosin mesylate sustained-release tablets 4mg*10 tablets
Pinyin full code: KeDuoHua JiaHuangSuanDuoShaZuoZuoHuanShiPian
[Main ingredients]
Each tablet contains doxazosin mesylate equivalent to 4mg doxazosin.
[Properties]
This product is a white film-coated tablet, which shows a dark red and light pink double-layer tablet core after removing the coating.
[Indications/Main functions]
Symptomatic treatment of benign prostatic hyperplasia, hypertension.
[Specifications]
4mg*10 tablets (KeDuoHua)
[Usage and dosage]
When taking this sustained-release tablet, swallow the tablet completely with enough water. Do not chew, break or crush it before taking. It is not affected by whether you eat or not. The most common dose is 4mg once a day. The maximum dose used clinically abroad is 8 mg once a day. There is no clinical experience in China. The commonly used dose of doxazosin can be used for patients with renal insufficiency and elderly patients. For patients with hepatic insufficiency, please refer to [Precautions].
[Adverse Reactions]
In controlled clinical trials, the most common reactions are postural (rarely accompanied by syncope) or non-specific, including: 1. Systemic reactions: fatigue, discomfort, weakness, dry mouth, back pain, chest pain, flu-like symptoms; 2. Gastrointestinal reactions: abdominal pain, nausea, gastroenteritis, indigestion; 3. Skin reactions: itching; 4. Cardiovascular system reactions: hypotension, palpitations, tachycardia, edema, peripheral edema; 5. Respiratory system reactions: bronchitis, cough, rhinitis, respiratory tract difficulties, respiratory tract infections; 6. Musculoskeletal system reactions: myalgia; 7. Central and peripheral nervous system reactions: dizziness, headache, vertigo; 8. Psychological reactions: drowsiness; 9. Urinary system reactions: urinary incontinence, cystitis and urinary tract infections. In the clinical application of ordinary tablets after listing, the following adverse events have been reported: 1. Hematopoietic system reactions: thrombocytopenia, purpura, leukopenia; 2. Systemic reactions: allergic reactions, hot flashes, pain, weight gain; 3. Endocrine system reactions: male breast development; 4. Gastrointestinal reactions: constipation, diarrhea, vomiting, flatulence; 5. Cardiovascular system reactions: postural dizziness, syncope; 6. Respiratory tract reactions: aggravated bronchospasm, cough; 7. Liver/biliary system reactions: cholestasis, hepatitis, jaundice, abnormal liver function tests; 8. Musculoskeletal system reactions: joint pain, muscle cramps, muscle weakness; 9. Central and peripheral nervous system reactions: tremor, decreased sensation , paresthesia; 10. Psychiatric reactions: agitation, impotence, anorexia, depression, nervousness, anxiety, insomnia; 11. Skin: rash, hair loss, urticaria; 12. Special sensory reactions: blurred vision, tinnitus; 13. Urinary system reactions: hematuria, dysuria, urination disorder, frequent urination, nocturia, polyuria, abnormal penile erection and retrograde ejaculation; In addition, after the market launch, some hypertensive patients reported the following adverse events, but these events are generally difficult to distinguish from the symptoms that occur when not taking doxazosin, including bradycardia, tachycardia, palpitations, chest pain, angina, myocardial infarction, cerebrovascular accident, arrhythmia; In hypertension studies, the adverse events of sustained-release tablets are similar to those of ordinary tablets. In the benign prostatic hyperplasia trial, the total adverse events of sustained-release tablets were similar to those of placebo, but significantly lower than those of ordinary tablets. The adverse events after the first dose of 4mg sustained-release tablets are similar to those after the first dose of 1mg ordinary tablets.
[Contraindications] This product is contraindicated in patients with known allergies to quinazolines (such as prazosin and terazosin) or any of the ingredients in this product. It is contraindicated in patients with a recent myocardial infarction. If a myocardial infarction occurs in a patient who has been treated with doxazosin, the post-infarction treatment should be determined on an individual basis. This product is contraindicated in patients with a history of gastrointestinal obstruction, esophageal obstruction, or any degree of gastrointestinal tract stenosis.
【Drug Interactions】
1. The use of indomethacin or other nonsteroidal anti-inflammatory drugs with this product can weaken the antihypertensive effect. This may be due to the inhibition of renal prostaglandin synthesis and/or the retention of water and sodium. 2. Cimetidine can slightly increase the blood concentration and half-life of doxazosin, but its clinical significance is unknown. 3. The antihypertensive effect of other antihypertensive drugs is enhanced when used with this product, and the dose needs to be adjusted. 4. When estrogen is used in combination with this product, blood pressure increases due to fluid retention. 5. The combination of sympathomimetic amines with this product can weaken both the pressor effect of the former and the antihypertensive effect of the latter. 6. In vitro plasma studies have shown that doxazosin has no effect on the protein binding rate of digoxin, warfarin, phenytoin, and indomethacin.
【Precautions】
Patients should swallow the tablets whole when taking this product. They should not be chewed, broken or crushed. In this extended-release tablet, doxazosin is placed in a non-absorbable shell to slowly release the drug. The empty shell is excreted and may be seen in the stool. Postural hypotension/syncope As with all alpha-blockers, a small number of patients may experience postural hypotension during the initial treatment phase, which manifests as dizziness and weakness, and rarely loss of consciousness (syncope). When using alpha-blockers for treatment, patients should be informed of how to prevent orthostatic hypotension and what to do. When starting doxazosin, patients should be informed of how to prevent injury caused by dizziness or weakness. Combination with phosphodiesterase type 5 inhibitors Doxazosin should be used with caution in combination with phosphodiesterase type 5 (PDE5) inhibitors because symptomatic hypotension may occur in some patients. Studies of doxazosin extended-release tablets have not been conducted. Impaired liver function As with other drugs that are completely metabolized by the liver, patients with impaired liver function should use doxazosin with caution. Gastrointestinal AbnormalitiesThe significantly reduced gastrointestinal residence time of doxazosin extended-release tablets may affect the pharmacokinetic properties and clinical efficacy of the drug. Similar to other non-deformable materials, this drug should be used with caution in patients with severe gastrointestinal tract stenosis (pathological or iatrogenic). There have been rare reports of patients with gastrointestinal stenosis experiencing obstructive symptoms after taking another non-deformable extended-release drug. Intraoperative Floppy Iris SyndromeFloppy iris syndrome (IFIS, a small pupil syndrome) during cataract surgery has been observed in some patients who have been or are currently treated with alpha-1 blockers. Because IFIS may increase complications during cataract surgery, patients who are currently or have been treated with alpha-1 blockers should inform their ophthalmic surgeon before surgery. PriapismPriapism caused by alpha-1 antagonists (including doxazosin) (lasting for several hours and not resolved by sexual intercourse or masturbation) is extremely rare, but if not treated promptly it can lead to permanent impotence, so patients should be informed of the severity of this adverse reaction. Leukopenia/neutropenia In a controlled clinical trial of hypertensive patients treated with doxazosin mesylate tablets, a 2.4% and 1.0% decrease in white blood cells and neutrophils was observed in the doxazosin group compared with the placebo group, respectively. This phenomenon is also seen with other α-blockers. Other patients with angina should be treated with drugs that can effectively prevent angina attacks before receiving doxazosin treatment. When switching from ?-blockers to doxazosin, patients with angina should pay full attention to the withdrawal reaction of ?-blockers and doxazosin should not be started until the patient is hemodynamically stable. Patients with symptomatic heart failure should receive treatment for heart failure before taking doxazosin. Patients who have received treatment for heart failure should be followed up more frequently in the early stages of doxazosin treatment, given the possibility of worsening of the disease. Treatment of benign prostatic hyperplasia should be carried out in collaboration with a urologist. Regular examinations should be performed before and during treatment to rule out prostate cancer. Prostate cancer can be detected through digital examination, recording of symptoms, and measurement of prostate-specific antigen (PSA). Effects on the ability to operate a machine Normally, this product has no effect on the ability to drive or operate a machine, but patients should be informed that this product can cause dizziness and fatigue (especially when treatment is just beginning), which can lead to decreased reaction ability.
[Drug use in children] The effectiveness and safety of this product in children have not been confirmed.
[Drug use in elderly patients] Conventional doses of doxazosin can be used in patients with impaired renal function and elderly patients. For patients with impaired liver function, see [Precautions].
[Overdose] If the drug overdose causes hypotension, the patient should lie flat immediately with the head down, and other necessary supportive treatments can be taken according to individual conditions. Due to the high binding rate of doxazosin to plasma proteins, dialysis is not suitable for drug overdose.
[Pharmacology and toxicology] Not yet clear
