Alyq

Generic name: Tadalafil

Drug class: Agents for pulmonary hypertension

Dosage form: 20 mg, oval-shaped, film-coated tablets (not scored) debossed with “TEVA” on one side and “3334” on the other side

Route of administration: Oral

Dose: The recommended dose is 40 mg (two 20 mg tablets) taken once daily with or without food. Dividing the dose over the course of the day is not recommended. In patients with mild to moderate renal impairment (creatinine clearance 31 to 80 mL/min), dosing may start at 20 mg once daily, increasing to 40 mg once daily based on individual tolerability. In patients with severe renal impairment (creatinine clearance <30 mL/min and on hemodialysis), the use of tadalafil is not recommended due to increased exposure and limited clinical experience. In patients with mild to moderate hepatic impairment (Child-Pugh Class A or B), consider a starting dose of 20 mg once daily. The use of tadalafil is not recommended in patients with severe hepatic impairment (Child-Pugh Class C) due to limited clinical experience. No dose adjustment is required in patients over 65 years of age without renal or hepatic impairment. Coadministration with ritonavir requires dosage adjustment; in patients receiving ritonavir for at least one week, start tadalafil at 20 mg once daily, increasing to 40 mg once daily based on individual tolerability. Avoid use during the initiation of ritonavir; stop tadalafil at least 24 hours prior to starting ritonavir, then resume at 20 mg once daily after at least one week, increasing to 40 mg once daily based on individual tolerability.

Mechanism of action: Tadalafil is a selective, reversible inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Inhibition of PDE5 by tadalafil increases cGMP levels in the corpus cavernosum, leading to smooth muscle relaxation and increased blood flow, resulting in an erection. This mechanism also applies to the smooth muscle of the prostate, bladder, and their vascular supply, leading to vascular relaxation and increased blood perfusion, which may reduce symptoms of benign prostatic hyperplasia.

Drug usage cases:

• Treatment of pulmonary arterial hypertension (PAH) to improve exercise ability
• Management of erectile dysfunction
• Symptomatic treatment of benign prostatic hyperplasia (BPH)

Drug contraindications:

• Concurrent use with organic nitrates (e.g., nitroglycerin, isosorbide dinitrate, isosorbide mononitrate) due to the risk of significant hypotension
• Concurrent use with guanylate cyclase (GC) stimulators such as riociguat, as tadalafil may potentiate their hypotensive effects
• Known serious hypersensitivity to tadalafil, including reactions such as Stevens-Johnson syndrome and exfoliative dermatitis

Side effects:

• Headache
• Myalgia
• Nasopharyngitis
• Flushing
• Respiratory tract infection
• Extremity pain
• Nausea
• Back pain
• Dyspepsia
• Nasal congestion
• Sudden decrease or loss of vision (non-arteritic anterior ischemic optic neuropathy)
• Sudden decrease or loss of hearing
• Prolonged erection (priapism) lasting more than 4 hours
• Chest pain
• Dizziness
• Hypotension

Warnings:

• Use with caution in patients with cardiovascular conditions, as tadalafil may cause transient decreases in blood pressure
• Not recommended for use in patients with pulmonary veno-occlusive disease (PVOD) due to potential worsening of cardiovascular status
• Use with caution in patients with anatomical penile deformation (e.g., Peyronie’s disease) or conditions predisposing to priapism
• May cause dizziness; patients should be advised to avoid activities requiring alertness until they know how the drug affects them
• Alcohol may enhance the blood pressure-lowering effect of tadalafil; patients should limit alcohol intake
• Use with caution in patients with a history of bleeding disorders or active peptic ulcer disease
• Not recommended for use in patients with severe renal or hepatic impairment
• Use with caution in patients with retinitis pigmentosa, a rare hereditary eye disease
• May cause sudden decrease or loss of vision; patients should seek immediate medical attention if this occurs
• May cause sudden decrease or loss of hearing; patients should seek immediate medical attention if this occurs
• May cause prolonged erection (priapism); patients should seek immediate medical attention if an erection lasts more than 4 hours

Use during pregnancy or breastfeeding: The safety of tadalafil during pregnancy has not been established. It should be used during pregnancy only if clearly needed, and the potential benefits should be weighed against the potential risks. It is not known whether tadalafil is excreted in human breast milk. Caution should be exercised when administering tadalafil to a nursing woman, and the potential benefits should be weighed against the potential risks.