What Is Tadalafil?

Tadalafil tablets are a selective, reversible inhibitor of cyclic guanosine monophosphate (cGMP) -specific phosphodiesterase 5 (PDE5). When sexual stimulation results in the local release of nitric oxide, PDE5 is inhibited by tadalafil, making Increased cGMP levels in the penile cavernous body, which results in smooth muscle relaxation, blood flow into penile tissue, and erections, such as asexual stimulation.

Chinese name: Tadalafil
English name: Tadalafil
nickname: Cialis, xlstm, Cialis

Chemical formula: C22H19N3O4
Molecular weight: 389.41
CAS Registry Number: 171596-29-5

Tadalafil compounds

Tadalafil Basic Information

Chinese name: Tadalafil

Chinese alias: ALPHA-[[(2R) -2-[(1S) -1-hydroxy-2- (hydroxyamino) -2-oxoethyl] -4-methyl-1-oxopentyl] amino ] Cyclopentyl phenylacetate; tadalafil;

English name: Tosdostat

English alias: cyclopentyl (2S) -2-[[(2R) -2-[(1S) -1-hydroxy-2- (hydroxyamino) -2-oxoethyl] -4-methylpentanoyl] amino] -2-phenylacetate; CHR2797 -Tosedostat; CHR-2797; UNII-KZK563J2UW; CAS number: 238750-77-1

Molecular formula: C ₂₂ H ₁₉ N ₃ O ₄

Molecular weight: 406.47300

Exact mass: 406.21000

PSA: 124.96000

LogP: 2.64010

Physical and chemical properties

Density: 1.24

Refractive index: 1.566

Storage conditions: Store at -20 ° C ^[1-2]

Tadalafil related drug label

Tadalafil pharmacokinetics

Quickly absorbed after oral administration, the median time to 2 hours after taking the drug reached the average maximum observed plasma concentration (Cmax). The absolute bioavailability after oral administration of this product is not yet clear. The absorption rate and degree of tadalafil are not affected by food, so this product can be taken with or without food. The time of administration (morning or evening) has no clinically significant effect on the absorption rate and extent. The average volume of distribution is about 63 liters, indicating that tadalafil is distributed into the tissue. At therapeutic concentrations, 94% of tadalafil binds to proteins in plasma. Protein binding is not affected by impaired renal function. The average clearance of oral tadalafil in healthy subjects is 2.5 L / hr and the average half-life is 17.5 hours. Tadalafil is excreted mainly as inactive metabolites, mainly from feces (about 61% of the dose ), A small part is excreted from the urine (about 36% of the dose)

Tadalafil applicable symptoms

Erectile dysfunction

Pulmonary hypertension

Tadalafil dosage

The recommended dose of this product is 10mg. It is taken before sexual life and is not affected by eating. If taking 10mg is not effective, you can take 20mg. It can be taken at least 30 minutes before sexual life.

The maximum frequency of medication is once daily.

Tadalafil side effects

Swollen eyelids, or described as eye pain and conjunctival congestion, are very rare side effects. The report showed that the side effects caused by tadalafil were transient, mild, or moderate. These side effects are that the data are only applicable to patients under 75 years of age.

Tadalafil Taboo

Clinical studies have shown that tadalafil can enhance the hypotensive effect of nitrates. This is thought to be the result of nitrate and tadalafil acting together on the nitric oxide / cGMP pathway. Therefore, patients who are taking any form of nitrate are prohibited from taking this product. (See "Drug Interactions" for details)

Sexual life poses potential heart risks for people with heart disease. Therefore, erectile dysfunction, including tadalafil, should not be used for patients with heart disease who are advised not to have sex. For patients who already have heart disease, doctors should consider the potential heart risks of sexual life. The clinical trials that have been performed do not include the following patients with cardiovascular disease, so these people are strictly prohibited from taking tadalafil:

Patients with myocardial infarction in the last 90 days

Patients with unstable angina or who have experienced angina during intercourse

Patients with heart failure who have reached the New York Heart Association diagnostic criteria level 2 or higher within the past 6 months

Patients with refractory arrhythmia, hypotension (<90 / 50mmHg), or refractory hypertension

Patients who have had a stroke in the last 6 months

People who are known to be allergic to tadalafil and its ingredients should not take this product

Tadalafil Notes

Before considering the administration of medication, a medical history and physical examination of the patient should be performed to diagnose male erectile dysfunction and identify possible unknown causes.

Because the incidence of cardiovascular disease is related to a certain degree of sexual behavior, doctors should consider the cardiovascular health of patients before treating male patients with erectile dysfunction, including tadalafil. Because tadalafil has The property of dilating blood vessels, so that it leads to a slight, temporary decrease in blood pressure (see "Pharmacology and Toxicology"), this property may enhance the antihypertensive effect of nitrate (see "Contraindications").

Severe cardiovascular diseases, including myocardial infarction, unstable angina pectoris, ventricular arrhythmia, shock, transient ischemic attacks, etc. have been observed in clinical trials of tadalafil. In addition, hypertension and hypotension (including orthostatic hypotension) are occasionally seen in clinical trials. Most of the patients who have the above situation have cardiovascular factors before taking the medicine. However, it is unclear whether these events are related to these risk factors.

There is limited clinical safety information on the use of this product in patients with severe liver dysfunction (Child-Pugh grade C); if such patients are prescribed, a prescribing physician will need to perform a careful benefit / risk assessment for each patient.

Clinical trials of tadalafil have not reported abnormal erections. However, sildenafil, another PDE5 inhibitor, has reported abnormal erections, and patients should be advised to seek immediate treatment if their erections exceed 4 hours or more. If the penile erection is not treated in time, it may cause damage to the penile tissue and permanent loss of erectile capacity.

Tadalafil should be used with caution in patients who are prone to abnormal erections (such as sickle cell anemia, multiple myeloma, or leukemia), or who have abnormal penile anatomy (such as penile angulation, deformed penis, cavernous fibrosis Or Peyronie disease).

The diagnosis of penile erectile dysfunction should include identifying the underlying cause and determining appropriate treatment after appropriate evaluation. It is unclear whether this product is effective for patients with spinal cord injury, patients with pelvic surgery, and patients with prostatectomy.

Tadalafil cannot be used in patients with inherited galactose intolerance, or patients with galactolytic enzyme deficiency, or patients with glucose-galactose malabsorption.

Patients who are using alpha (1) blockers, such as doxazosin, may cause symptomatic hypotension in some patients if used in combination (see "Pharmacological Interactions"). Therefore, the combined use of tadalafil and alpha blockers is not recommended.

Special care should be taken if overtadala is prescribed to patients who are using potent CYP3A4 inhibitors (eg, ritonavir, saquinavir, ketoconazole, itraconazole, erythromycin). Because tadalafil has been found to be used in combination with these drugs to increase the exposure (AUC) of tadalafil (see "Drug Interactions" for details)

The safety and efficacy of this product in combination with other erectile dysfunction treatments have not been studied. Therefore, this combination is not recommended.

In a dog trial, tadalafil was administered daily at a dose of 25 mg / kg / day or more for 6-12 months (at least three times higher than a single human dose of 20 mg / kg / day). The exposure rate [range 3.7-18.6]) was found to degenerate the vas deferens of some test dogs, which resulted in a decrease in sperm counts. The results of continuous 6-month studies in healthy volunteers in two groups showed that The clinical phenomena observed in the above-mentioned dog trials do not occur (see "Pharmacology and Toxicology"). Consequences of long-term continuous daily tadalafil use have not been established, and therefore continuous daily use is prohibited.

Tadalafil has no effect or neglect on the ability to drive and operate machines. No special studies have been conducted on this potential impact. Although the frequency of vertigo reported in the placebo and tadalafil groups was similar in clinical trials, patients should be aware of their response to tadalafil before driving and operating machines.

Tadalafil adverse reactions

The most reported side effects are usually headaches and indigestion, and eyelid swelling or described as eye pain and conjunctival congestion are rare side effects. Reports show that the side effects caused by tadalafil are transient, mild, or moderate.

Tadalafil contraindications

-Patients who are taking any form of nitrate.

-The following populations: patients with myocardial infarction in the last 90 days; patients with unstable angina pectoris or angina during intercourse; heart failure that has reached the New York Heart Association diagnostic criteria level 2 or above within the past 6 months Patients; patients with refractory arrhythmia, hypotension (<90 / 50mmHg), or patients with refractory hypertension; patients with stroke in the last 6 months

-Patients known to be allergic to tadalafil and its ingredients. ^[3]