01What do strong CYP3A4 inhibitors do to the route?
Ketoconazole or ritonavir with as-needed tadalafil: 10 mg is the ceiling, not more often than every 72 hours. With once-daily tadalafil the dose is 2.5 mg. Those are labelled caps, not a reason to switch routes without a new written line.
02Can both routes run in the same week?
No. The label does not add an as-needed 20 mg on top of a daily 5 mg tablet. Once per day is the cap on either route. If the written line is daily, a weekend extra tablet is not a labelled top-up.
A clinician who wants a different route writes a new line. The pharmacy fills that line. How the first US order is written sits on how to get tadalafil.
03Does the 17.5-hour half-life pick the route?
Mean terminal half-life is 17.5 hours in healthy men. That number sits behind a long as-needed clock. It is not a reason to write daily 5 mg, and it is not a reason to add a second tablet. Daily use is a separate labelled route with steady state at 5 days.
Healthy elderly men had a 25 percent higher AUC and no Cmax change. The label does not cut the dose for age alone and does not switch the route for age alone. About 25 percent of men in the ED trials were 65 and over; about 3 percent were 75 and over.
04Does the daily route skip stimulation?
No. Daily tadalafil still needs sexual stimulation. The daily bottle keeps a plasma level; it does not start an erection on its own. A meal still does not hold the swallow. See Cialis and food.
05Do kidneys change which route is open?
Creatinine clearance 30 to 50 mL/min: as-needed starts at 5 mg and is not more often than every 48 hours; daily starts at 2.5 mg. Creatinine clearance under 30 mL/min, or hemodialysis: as-needed 5 mg not more often than every 72 hours; the daily route is not recommended.
Severe hepatic impairment: tadalafil is not recommended. Mild or moderate hepatic impairment: as-needed 10 mg is the ceiling; daily use is not recommended. Those cuts belong on the written order, not as a second tablet at home.
06What is the as-needed route?
As-needed erectile dysfunction starts at 10 mg, taken before sexual activity. The dose may increase to 20 mg or decrease to 5 mg. The tablet is not taken more than once a day. Food does not hold that swallow. Stimulation still has to start the erection.
The 24-hour stopwatch read used as-needed 20 mg. That clock lives on how long Cialis lasts at 24 hours. This page does not repeat those percents.
07What is the once-daily route?
Once-daily erectile dysfunction starts at 2.5 mg at about the same time each day and may increase to 5 mg. Steady state is reached at 5 days. Exposure at steady state is about 1.6 times a single dose. This site's tadalafil shelf locks that 5 mg daily line.
BPH, and ED plus BPH, are written as 5 mg once daily. Those indications do not use the as-needed 10-to-20 ladder. First weeks on the daily bottle are a different clip: daily stock.