What is the recommended dosage of tadalafil for pah?

For pulmonary arterial hypertension (PAH), tadalafil is typically prescribed at 40 mg taken once daily by mouth. If you have only 20 mg tablets, that usually means taking two tablets once daily to equal 40 mg. It can be taken with or without food.

Important cautions:
- Do not take tadalafil with nitrates (e.g., nitroglycerin) or with riociguat, as this can cause dangerous drops in blood pressure.
- If you are also taking bosentan or other interacting drugs, your doctor may adjust the tadalafil dose; follow their instructions exactly.
- Do not exceed 40 mg daily unless your clinician has explicitly instructed you to.

If you were asking about a different context (e.g., erectile dysfunction), the dosing is different. If you want, I can clarify that as well or pull up the official labeling for PAH.