What is N-desmethyl tadalafil?

Drug N - desmethyl tadanafil containing the active ingredient tadanafil is indicated in the treatment of erectile dysfunction, benign prostatic hyperplasia, pulmonary arterial hypertension. Let's learn about the notes when using N-desmethyl tadalafil through the article below.

1.1. Indications “What is N-desmethyl tadalafil?”. The drug N-desmethyl tadalafil contains the active ingredient tadanafil, which is indicated in the following conditions:
Erectile dysfunction in adult men, the drug requires sexual stimulation for effective treatment; Benign prostatic hyperplasia (BPH); Patients with concomitant benign prostatic hyperplasia and erectile dysfunction; Patients with pulmonary arterial hypertension (PAH). 1.2. Pharmacodynamics Active ingredient Tadanafil is a reversible, selective inhibitor of cyclic quanosin monophosphate (cGMP), especially phosphodiesterase type 5 (PDE5). The aphrodisiac activity results in local release of nitric, and the PDE5 inhibitory effect of tadanafil increases cGMP concentrations in the corpus cavernosum. This relaxes smooth muscle, increases blood flow to the tissues of the penis, and causes an erection. The drug has no effect without sexual stimulation.
1.3. Pharmacokinetics Absorption: The drug is rapidly absorbed after oral administration and is not affected by food. Peak plasma concentrations are reached 0.5 to 6 hours after oral administration. After a single dose, the drug is effective within 30 minutes. Works to improve erection for up to 36 hours.
Distribution: Approximately 94% of Tadanafil is bound to plasma proteins.
Metabolism: The drug is metabolised mainly in the liver (mainly by the enzyme CYP3A4) to inactive metabolites.
Elimination: Tadanafil is eliminated in feces (approximately 61%) and urine (approximately 36%) as metabolites. The drug is not significantly eliminated by hemodialysis, the half-life (t1/2) is approximately 17.5 hours.

The dose of N-desmethyl tadalafil depends on the age and condition of the patient. The recommended dosage of N-desmethyl tadalafil is as follows:
Adults:
Treatment of erectile dysfunction:
Once-daily dosing: Start with 2.5mg orally once daily in the same day. time, the dose can be increased to 5mg/day based on the clinical efficacy of the drug; Therapeutic dose as needed: The initial dose is usually 10mg orally 30 minutes before sexual intercourse. Dosage may be increased to 20 mg or decreased to 5 mg based on clinical efficacy and tolerability. The maximum number of times of medication is 1 time / day. Treatment of benign prostatic hyperplasia: The recommended dose is 5mg/time/day at the same time. The drug is used for up to 26 weeks when treated with Finasteride.
Simultaneous treatment of erectile dysfunction and benign prostatic hyperplasia: The recommended dose is 5mg/time/day at the same time of day.
Treatment of pulmonary arterial hypertension i: The recommended dose is 40mg/time/day at the same time, can be taken with or without food.

N-desmethyl tadalafil can cause some side effects as follows:
Common: Dizziness, headache, insomnia, anxiety, fever, flushing, dizziness, nosebleeds, indigestion, swelling nasal bleeding, vomiting, blurred vision, astigmatism, photophobia, optic neuropathy, retinal vein thrombosis, retinal artery occlusion, respiratory tract infection, nasopharyngitis; Uncommon: Angina pectoris, neuralgia, myocardial ischemia, sudden cardiac death, myocardial infarction, tachycardia; Rare: Pulmonary hemorrhage, asthma, rectal bleeding, colitis, stomatitis, allergic reactions, hypersensitivity reactions, edema, exfoliative dermatitis, hearing loss, Stevens-Johnson syndrome, hearing loss suddenly.

4.1. Contraindications N-desmethyl tadalafil is contraindicated in the following cases:
Patients taking the drug form of organic nitrates (e.g. nitrites, nitrates or nitric oxides) frequently or intermittently for a period of time. 48 hours from the last dose of Tadanafil; Patients taking concomitant guanylate cyclase stimulators (eg, Riociguat); Patients with known hypersensitivity to Tadanafil or any component of N-desmethyl tadalafil ; Male patients need to avoid sexual activity due to unstable cardiovascular disease; Patients with myocardial infarction within the past 90 days; The patient has unstable angina or muscle angina that occurs during sex; Patients with severe heart failure in the past 6 months; Patients with uncontrolled arrhythmias, patients with low blood pressure (less than 90/50mmHg) or uncontrolled hypertension; The patient had a cerebrovascular accident in the past 6 months. 4.2. Precautions while using N-desmethyl tadalafil The efficacy and safety of Tadanfil in people under 18 years of age have not been evaluated. Therefore, it is not recommended to use the drug in these subjects.
Do not combine N-desmethyl tadalafil with other PDE5 inhibitors or other therapies to treat erectile dysfunction because the safety and effectiveness of these drugs have not been studied.
Concomitant use of N-desmethyl tadalafil with CYP3A4 inducers or inhibitors requires dose adjustment, not recommending concomitant use of these substances.
Do not use Tadanafil in combination with alpha channel blockers.
For people with cardiovascular disease, it is necessary to assess the patient's cardiovascular status before treatment with N-desmethyl tadalafil. Serious effects associated with Tadanafil that have been reported include stroke, sudden cardiac arrest, myocardial infarction, palpitations, chest pain, and tachycardia. Its use is not recommended in patients with myocardial infarction within the last 90 days or a stroke within the last 60 days, in patients with uncontrolled arrhythmias, hypotension or uncontrolled hypertension. Controllable...
Effects of drugs on hearing and vision: Stop drug treatment and immediately notify the treating doctor in case of sudden loss of hearing or vision. Do not use the drug in patients with hereditary degenerative retinal disorders (including retinitis pigmentosa.
Effects of the drug on the urogenital tract: N-desmethyl tadalafil should be used with caution in patients with anatomical deformities of the penis (cystic fibrosis, penile flexion, Peronie's disease) and diseases that cause penile pain (multiple myeloma, sickle cell anemia, leukemia). Drugs on hematology: Caution should be taken when using N-desmethyl tadalafil in patients with severe peptic ulcer disease, bleeding disorders
Note for pregnant women, lactating women. : Do not use drugs in these subjects.

N-desmethyl tadalafil may enhance the antihypertensive effect of alpha channel blockers, organic nitrates and some other antihypertensive agents. Therefore, avoid the use of these drugs in combination; cytochrome P450 CYP3A4 inhibitors (cimetidine, HIV protease inhibitors, antivirals, delavirdine, itraconazole and ketoconazole) may decrease the clearance of N-desmethyl tadalafil, leading to increased plasma concentrations of the drug; CYP3A4 inducers (carbamazepine, rifampicine, phenobarbital and phenytoin) may decrease tadanafil plasma concentrations. Drug-food interactions:
Do not use N-desmethyl tadalafil with grapefruit juice because it may increase the plasma concentration of the drug; Drinking too much alcohol (more than 4 drinks in a short time) can increase blood pressure and dizziness caused by Tadanafil. Above is important information about the drug N-desmethyl tadalafil. Knowing the information about the drug will help the treatment process to be more effective.