I. name of the drug
Tadalafil is tadalafil, and 20mg is a common dose specification.
Second, pharmacological action
1 、Mechanism of action
Tadalafil is a selective phosphodiesterase 5 (PDE5) inhibitor. In male cavernous smooth muscle cells, PDE5 can degrade cyclic guanosine monophosphate (cGMP), while sexual stimulation promotes the release of nitric oxide (NO) in the cavernous body. NO activates guanylate cyclase, resulting in an increase in cGMP levels, resulting in relaxation of cavernous smooth muscle and blood flow into the cavernous body, resulting in erection. Tadafil inhibits PDE5. Improve the level of cGMP and enhance erectile function.
2 、Efficacy characteristics
Tadalafil acts for a long time, takes effect within 1-2 hours after oral administration, and lasts for about 36 hours, which is different from some other short-acting PDE5 inhibitors.
III. Application
1 、Erectile dysfunction (ED)
-used in the treatment of male erectile dysfunction, patients with sexual stimulation, taking tadalafil can improve the hardness and duration of penile erection and improve the quality of sexual life.
2 、Pulmonary hypertension (PAH)
-under certain circumstances, it can also be used to treat pulmonary hypertension, which can improve the symptoms and exercise tolerance of patients with pulmonary hypertension by relaxing pulmonary vascular smooth muscle and reducing pulmonary vascular resistance.
IV. Usage and dosage
1 、Treatment of erectile dysfunction
-for most patients, the recommended starting dose is 10mg, which can be increased to 20mg or reduced to 5mg according to individual efficacy and tolerance, with a maximum frequency of once a day.
-you can also use a daily regular treatment plan, the initial dose is 2.5mg, and adjust the dose to 5mg or 10mg according to the patient's response.
2 、Treatment of pulmonary hypertension
-the recommended dose is 40mg (once daily).
5. Adverse reactions
1 、Common adverse reactions
Headache is a common adverse reaction, usually mild to moderate, which may be related to the vasodilating effect of drugs.
-indigestion, including stomach distension, stomachache, nausea and other symptoms.
-back pain, myalgia, which may affect the muscles of the waist and limbs.
-facial flushing, which is caused by skin redness and fever caused by vasodilation.
2 、Rare adverse reactions
-there may be visual abnormalities, such as blurred vision, color vision changes, etc., although the incidence is low, but if it occurs, you should seek medical advice in time.
A small number of patients may have neurological symptoms such as tinnitus and dizziness.
VI. points for attention
1 、Contraindication
-Tadalafil is prohibited in patients who are taking any form of nitrates (such as nitroglycerin, isosorbide dinitrate, etc.) because a combination of the two can lead to severe hypotension.
-it is forbidden for people who are allergic to tadarafi.
2 、Special crowd
-the elderly: there is no need to adjust the dose, but it may be more prone to adverse reactions and require close attention.
Patients with renal insufficiency: patients with mild to moderate renal insufficiency do not need to adjust the dose, but patients with severe renal insufficiency should be limited to less than 5mg and the maximum frequency of medication should be once every 72 hours.
-patients with liver insufficiency: the recommended dose is 10mg for patients with mild to moderate liver insufficiency, but not for patients with severe liver insufficiency.
Women: tadalafil is not suitable for women, and there are currently no indications for women.