Tadalafil tablets

1. Tadalafil is a selective, reversible inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase 5 (PDE5). When sexual stimulation causes the local release of nitric oxide, PDE5 is inhibited by tadalafil, which increases the level of cGMP in the corpus cavernosum. This causes smooth muscle relaxation, blood flow into the penile tissue, and erection. If there is no sexual stimulation, tadalafil has no effect. 2. In vitro studies have shown that tadalafil is a selective inhibitor of PDE5. PDE5 is an enzyme present in the smooth muscle of the corpus cavernosum, blood vessels and visceral smooth muscle, skeletal muscle, platelets, kidneys, lungs and cerebellum. Tadalafil has a stronger effect on PDE5 than on other phosphodiesterases. Tadalafil's effect on PDE5 is more than 10,000 times stronger than its effect on PDE1, PDE2, PDE4, etc. found in the heart, brain, blood vessels, liver and other organs. Tadalafil's effect on PDE5 is more than 10,000 times stronger than its effect on PDE3 found in the heart and blood vessels. The selectivity for PDE5 over PDE3 is important because PDE3 is involved in myocardial contractility. In addition, the potency of tadalafil on PDE5 is about 700 times that of PDE6, which is present in the retina and is involved in phototransduction. The potency of tadalafil on PDE5 is more than 10,000 times higher than that on PDE7-10. 3. Three studies involving 1,054 patients determined the time of patient response to tadalafil. Compared with placebo, this product was shown to have statistically significant improvements in erectile function, the ability to have successful sexual intercourse, and the ability to achieve and maintain an erection for successful sexual intercourse as short as 16 minutes and as long as 36 hours after taking the drug. 4. Compared with placebo, there was no significant difference in systolic and diastolic blood pressure in the supine position (mean maximum decrease of 1.6/0.8 mmHg, respectively) and in the standing position (mean maximum decrease of 0.2/4.6 mmHg, respectively) after taking tadalafil in healthy subjects, and there was no significant change in heart rate. 5. In the study evaluating the effects of tadalafil on vision, no impairment of color discrimination ability (blue/green) was found using the Farnsworth-Munsell 100-hue color test. This result is consistent with the lower affinity of tadalafil for PDE6 than for PDE5. Reports of changes in color vision were rare (0.1%) in all clinical trials. 6. Three trials were conducted in men, taking tadalafil 10 mg (for 6 consecutive months) and 20 mg (for 6 consecutive months and 9 consecutive months) daily to study the effects of tadalafil on spermatogenesis. Two of the trials observed a decrease in sperm count and concentration, which is generally considered to be clinically irrelevant to tadalafil treatment. At the same time, these changes were not accompanied by changes in parameters such as sperm motility, sperm morphology, and FSH. 7. The effects of tadalafil 2-100 mg doses were evaluated in 16 clinical trials involving a total of 3,250 patients. These patients with erectile dysfunction have different severity (mild, moderate and severe), etiology, age (21-86 years) and race. The vast majority of patients reported suffering from erectile dysfunction for at least 1 year. In the initial efficacy study of the general population, 81% of patients reported that tadalafil improved erections, and the control group was 35%, (mild, moderate and severe were 86%, 83% and 72% respectively and the control group was 45%, 42% and 19% respectively). In the initial efficacy study, 75% of patients treated with this product had successful sexual intercourse attempts, while only 32% were successful after taking placebo. 8. In a 12-week trial conducted in 186 patients with erectile dysfunction secondary to spinal cord injury (142 tadalafil, 44 placebo), tadalafil significantly improved erectile function. In patients receiving 10 or 20 mg of tadalafil (adjustable dose, given when needed), the average successful attempt rate per subject was 48%, and the placebo was 17%.

Tadalafil

The 20 mg tablets are yellow, almond-shaped, and labeled "C20" on one side.

Treating erectile dysfunction

The recommended dose is 10 mg, taken before sexual intercourse, regardless of food intake. If 10 mg does not work, 20 mg can be taken. It can be taken at least 30 minutes before sexual intercourse. The maximum frequency of medication is once a day.

The most common adverse reactions are headache and dyspepsia. Other common adverse reactions include back pain, myalgia, nasopharyngitis, nasal congestion and facial flushing.

Patients with known allergy to tadalafil should not take tadalafil tablets

Precautions for children: This product should not be taken by persons under 18 years of age. Precautions for pregnancy and lactation: This product is not for women. Tadalafil has not been studied in pregnant women. Animal studies have not shown that this product has direct or indirect adverse effects on pregnancy, embryo/fetal development, and delivery and postnatal development. Precautions for the elderly: Oral tadalafil clearance is lower in healthy elderly subjects (65 years or older), resulting in an AUC that is 25% higher than that of healthy subjects aged 19-45 years. This age effect is not clinically significant and no dose adjustment is required.

The interaction studies described below used 10 mg and/or 20 mg of tadalafil. Since the dose used in the study was 10 mg of tadalafil, clinically relevant drug interactions cannot be completely ruled out when a larger dose is used clinically. Effects of other drugs on tadalafil Tadalafil is primarily metabolized by CYP3A4. 1. Compared with the AUC values and Cmax of tadalafil alone, ketoconazole (200 mg per day), a selective inhibitor of CYP3A4, can increase the exposure (AUC) of tadalafil (10 mg) by 2 times and Cmax by 15%. Ketoconazole (400 mg per day) can increase the exposure (AUC) of tadalafil (20 mg) by 4 times and Cmax by 22%. The protease inhibitor ritonavir (200 mg, twice a day) is a CYP3A4 inhibitor. 2. CYP2C9, CYP2C19, and CYP2D6 inhibitors can increase the exposure (AUC) of tadalafil (20 mg) by 2 times and have no effect on Cmax. 3. Although no specific interaction studies have been conducted, other protease inhibitors, such as saquinavir and other CYP3A4 inhibitors, such as erythromycin, clarithromycin, itraconazole and grapefruit juice, may increase the concentration of tadalafil in plasma. Therefore, the incidence of unpredictable adverse reactions may increase. 4. The effect of transport factors (such as P-glycoprotein) on the distribution of tadalafil is still unclear. Therefore, drug interactions caused by inhibitors of transport factors may occur. 5. Compared with the AUC value of tadalafil alone (10 mg dose), the CYP3A4 inducer rifampicin can reduce the AUC of tadalafil to 88%. Based on this, it is speculated that the combined use of other CYP3A4 inducers, such as phenobarbital, phenytoin, and carbamazepine, can also reduce the concentration of tadalafil in plasma. Clinical studies on the effect of tadalafil on other drugs have shown that tadalafil (10 mg and 20 mg) can enhance the antihypertensive effect of nitrate drugs. Therefore, patients who are taking any form of nitrate drugs are prohibited from taking this product (see contraindications). 6. Based on the results of a clinical study conducted in 150 subjects, 20 mg of tadalafil was given at different times daily for 7 days and 0.4 mg of sublingual nitroglycerin. This interaction lasted for more than 24 hours, and there was no interaction 48 hours after the last dose of tadalafil. Therefore, for patients using tadalafil, the timing of nitrate administration should be determined based on the needs and circumstances of treatment, and nitrate administration should be considered at least 48 hours after the last dose of tadalafil. In this case, nitrate drugs can only be administered under close medical monitoring and appropriate hemodynamic testing. Tadalafil does not produce clinically significant inhibition and induction of drug clearance metabolized by CYP450 isomers. Studies have confirmed that tadalafil does not inhibit or induce CYP450 isomers: CYP3A4, CYP1A2, CYP2D6, CYP2E1, CYP2C9 and CYP2C19. 7. Tadalafil (10mg and 20mg) does not have a clinically significant effect on the distribution (AUC) of S-warfarin or R-warfarin (substrates of CYP2C9); tadalafil also has no effect on changes in prothrombin time induced by warfarin. 8. Tadalafil (10mg and 20mg) does not enhance the prolonged bleeding time caused by acetylsalicylic acid. 9. Clinical pharmacology studies have verified the potential of tadalafil to enhance the antihypertensive effect of antihypertensive drugs. The main types of antihypertensive drugs were studied, including calcium channel blockers (amlodipine), angiotensin converting enzyme (ACE) inhibitors (enalapril), beta-adrenergic receptor antagonists (metoprolol), thiazide diuretics (bendroflumethiazide), and angiotensin II receptor inhibitors (different types and doses, alone or in combination with thiazides, calcium channel blockers, beta-receptor antagonists, and/or a-receptor inhibitors). 10. Tadalafil (the study dose of angiotensin II receptor inhibitors was 10 mg, and the study dose of amlodipine was 20 mg) had no clinically significant interactions with any of the above drugs. 11. In another clinical pharmacology study, tadalafil (20 mg) was studied in combination with 4 types of antihypertensive drugs. In subjects who were taking multiple antihypertensive drugs, the changes in blood pressure after activity showed a correlation with the degree of blood pressure control. In this regard, the subjects who participated in the study whose blood pressure was well controlled had a small drop in blood pressure, similar to that of healthy subjects. In subjects whose blood pressure was not controlled, the blood pressure dropped significantly, although this drop was not associated with hypotensive symptoms in most subjects. In general, in patients taking antihypertensive drugs at the same time, the reduction in blood pressure caused by tadalafil 20 mg (except alpha; receptor blockers - see below -) is of little or no clinical relevance. Analysis of information from Phase III clinical studies showed that there was no difference in adverse events between patients given tadalafil with or without antihypertensive drugs. However, patients who are taking antihypertensive drugs should be informed that combined use may reduce blood pressure. 12. Alcohol concentration (average maximum blood concentration 0.08%) is not affected by the simultaneous use of tadalafil (10 mg or 20 mg). There is no change in tadalafil concentration 3 hours after taking it simultaneously with alcohol. There is no change in tadalafil concentration 3 hours after taking it simultaneously with alcohol. When alcohol is administered at the maximum alcohol absorption rate (fasting the night before until 2 hours after alcohol administration), tadalafil (20 mg) does not show an increase in the decrease in mean blood pressure induced by alcohol (0.7 g/kg or 40% alcohol (vodka) administered to an 80 kg male is approximately 180 ml). However, postural vertigo and orthostatic hypotension were observed in some subjects. When tadalafil was used in combination with low doses of alcohol (0.6 g/kg), no hypotension was observed, and the frequency of vertigo was similar to that when alcohol was used alone. The effects of alcohol on cognitive function were not increased by the combined use of tadalafil (10 mg). 13. Tadalafil has been shown to increase the bioavailability of ethinyl estradiol after oral administration. It can be speculated that tadalafil can also increase the bioavailability of orally applied terbutaline, but this clinical effect is currently unclear. 14. In clinical pharmacology trials, no pharmacokinetic interactions were found when tadalafil (10 mg) was used together with theophylline (a non-selective phosphodiesterase inhibitor). The only pharmacokinetic effect was a slight increase in heart rate (3.5 beats/minute). Although this effect was small and not significant in this clinical trial, it should still be considered when used in combination. Studies on the interaction of tadalafil with hypoglycemic drugs have not been conducted.

Keep in a dry and cool place

20mg

24 months