01What if the bottle is daily, not 10 mg PRN?
Daily Cialis with ketoconazole or ritonavir is capped at 2.5 mg. That is a different bottle from this vault's 10 mg as-needed line. See daily versus 10 mg PRN.
Do not split a 10 mg film coat to manufacture that 2.5 mg. Tablets are not scored.
02Is itraconazole on the same potent row?
Itraconazole sits with ketoconazole and ritonavir on the potent CYP3A4-inhibitor row. The as-needed cap is still 10 mg every 72 hours when that azole is on the chart.
Bring the antifungal and antiviral list to the writer before anyone prices 10 mg as a weekend default.
03What is the as-needed cap with ketoconazole or ritonavir?
Ten milligrams, not more than once every 72 hours. That is the labelled as-needed ceiling when a potent CYP3A4 inhibitor is already on the chart. This vault's usual 10 mg start becomes a spacing problem.
A thirty-count of 10 mg is still a pack size. It is not a nightly permission slip on that row.
04Can 20 mg outrun the inhibitor?
Twenty milligrams is the as-needed step-up after a clean 10 mg read. It is not a way around ketoconazole. The cap on that row is 10 mg, not 20 mg.
See 10 mg start, then 20 or 5 when the inhibitor list is empty.
05Why does exposure rise on that row?
Tadalafil is predominantly metabolized by CYP3A4. Potent inhibitors raise the area under the curve. The 72-hour as-needed spacing is how the label handles that leftover.
Rifampin-type inducers can flatten the window you wanted. That is the other side of the same enzyme, not this cap.
06Is grapefruit the same cap as ritonavir?
Grapefruit can raise tadalafil exposure. It is not the same labelled 72-hour cap as prescribed ritonavir or ketoconazole. Tell the writer what you actually drink with the tablet.
Food still leaves rate and extent unmoved. That meal job is the meal probe.