01 The 59-man hour is the number this margin keeps
Read the interval before anyone writes 20 mg. The labelled QT study used 10 mg and 80 mg (four times the highest recommended tablet) in 59 healthy men aged 45 to 60, crossover against placebo and moxifloxacin 400 mg. QT was read at 1 hour because that approximates peak vardenafil.
Fridericia QTc versus placebo: +8 msec (90% CI 6 to 9) at 10 mg, +10 msec (8 to 11) at 80 mg. Moxifloxacin +8 msec (6 to 9). Heart rate rose about 5 beats per minute at 10 mg and 6 at 80 mg. No single QT correction is declared more valid than another on that table.
Those are small mean shifts. They are still enough for the insert to tell patients with congenital QT prolongation, or on class IA or class III antiarrhythmics, to avoid Levitra. A postmarketing combination study showed an additive QT effect with another QT-prolonging drug.
A family story of 'Dad's long QT' is a reason to review your own interval. It is not your ECG.
02 What to bring before anyone writes 20 mg
What to bring before anyone writes 20 mg: the antiarrhythmic list, macrolides and azoles, any prior syncope or documented long QT, and the last 10 mg trial (minutes, meal, stimulation). Twenty milligrams is the ceiling after 10 mg, not a QT-positive shortcut.
Age 65 and over had higher Cmax and AUC and often starts at 5 mg. That start-low cue is not a QT study, but it belongs on the same line.
Alpha-blockers share a pressure story, not a QT story. Still mention them. Simultaneous Tmax with terazosin dropped standing pressure hard enough to stop a study arm.
The onset margin that stops a 2.5 mg origin myth is peak notes, not 2.5 first.
03 Small mean shifts are not a reason to skip a history
Small mean shifts are not a reason to skip a history, and they are not a reason to panic every man with a normal ECG. Therapeutic 10 mg and supratherapeutic 80 mg sat near moxifloxacin in that one design. The clinical rule is the named avoidance groups plus additive combinations, not a home QTc hobby.
Sildenafil and tadalafil do not copy this vardenafil QT paragraph in the same words. If the visit is really about a food-proof weekend, the tadalafil leaf may be the better clock and avoids this screen. That is a clinician pick, not a self-swap the night an amiodarone starts.
Do not stop a needed antiarrhythmic to 'make 20 mg legal.' Stop the vardenafil plan instead.
Sudden faint, palpitations, or a family sudden-death story after a first 10 mg: emergency care, not a 20 mg experiment.
- Avoid: congenital long QT, class IA, class III
- Additive risk: other QT-prolonging drugs
- Ritonavir: dose row breaks 20 mg before QT is the main topic
- Nitrates: still banned after a clean interval
04 Why Cialis and Viagra do not copy this QT paragraph
Why Cialis and Viagra do not copy this QT paragraph: the Levitra insert names congenital long QT and class IA/III antiarrhythmics as avoidance groups and publishes the 59-man Fridericia table. Sildenafil and tadalafil labels do not reprint that table in the same words. That is not a claim that those INNs are 'QT-proof.' It is a claim that vardenafil 20 mg carries extra named homework.
If an antiarrhythmic starts this month, do not self-swap to 50 mg sildenafil at 22:00 without a visit. Nitrates, riociguat, and CYP rows still apply to the other clocks.
If the only reason for vardenafil was a fast peak, and the QT list is dirty, the cleaner clocks are tadalafil (food-proof, 48-hour nitrate hold) or sildenafil (after-food hour, 24-hour practical hold). Those are clinician picks.
Do not stack a 'little 10 mg Levitra' on sotalol because 20 mg felt too loud. Class III is an avoid line at both strengths.
A family sudden-death story plus a first 10 mg faint is emergency care, not a 20 mg titration. France: 15 or 112, last tablet time first.
05 Quoted 20 mg ten-count after the screen
Quoted 20 mg ten-count after the screen sits on the parent leaf's GoodRx row (6 July 2026). A clean QT does not change that caption. Staxyn ODT is not this NDC.
Virena does not dispense and does not read your ECG.
Generic vardenafil 20 mg x 10, GoodRx Levitra table, 06 July 2026.
Generic vardenafil 20 mg, ten tablets, the Virena Levitra ceiling lock, August 2026. GoodRx Levitra table lists 20 mg x 10 at $573.78 average retail and $44.21 with a coupon (06 July 2026). Staxyn ODT is not this tablet NDC. Virena does not dispense.
06 What a QT visit actually needs on the table
What a QT visit actually needs on the table: the antiarrhythmic names, a recent clinic ECG if one exists, syncope or documented long QT, the last 10 mg vardenafil trial, and the nitrate list. A watch screenshot can travel with those facts. It cannot replace them.
Congenital long QT is an avoid-Levitra line even if the person feels well. Acquired long QT from a drug you still need is the same avoid line. Stopping the antiarrhythmic to open 20 mg is the wrong object.
Ritonavir belongs on that table because it breaks the 20 mg dose row (often a single 2.5 mg in a long interval) and because the 80 mg QT arm was chosen to cover ritonavir-level concentrations. QT and dose interact here.
Alpha-blockers are a pressure story. Still put them on the table so nobody times 20 mg on top of 22:00 terazosin after clearing QT.
Emergency faint or palpitations after a first 10 mg is 15 or 112 in France, last tablet time first, not a 20 mg experiment the next night.
07 After the interval is clean, the 20 mg hour is still a 10 mg rise
After the interval is clean, the 20 mg hour is still a 10 mg rise. A normal ECG does not skip titration. Most adults still start at 10 mg about 60 minutes before activity. Age 65 and over often starts at 5 mg. Twenty milligrams is the ceiling after a fair 10 mg hour.
Food still cuts Cmax 18% to 50% after a high-fat meal. A clean QT plus a banquet can still blunt the fast peak you wanted.
Alpha-blockers still share a Tmax problem. Clearing QT does not clear terazosin at the same hour.
Nitrates still forbid the night. The 24-hour healthy-volunteer gap is not a coat-spray plan.
If the ECG is clean and 10 mg was fair and weak, then 20 mg is the labelled rise. If the ECG was never reviewed and class III is in the box, 20 mg is the wrong object.
08 Who does not get the 20 mg tablet at all
Who does not get the 20 mg tablet at all: congenital long QT, class IA drugs (quinidine, procainamide), class III drugs (sotalol, amiodarone, dofetilide). The insert names those groups. A watch-ECG screenshot is not the screen.
Other QT-prolonging medicines can add. The combination study is the warning, not a homemade list you complete from memory. Bring the full box to the visit.
Ritonavir raises vardenafil so high that 80 mg was chosen in the QT study to cover that interaction. A 20 mg ceiling tablet plus ritonavir is already the wrong object on the dose row (often a single 2.5 mg in a long interval) before QT is even discussed.
Nitrates remain a separate contraindication. A clean QT does not open a coat spray.
| Dose in the QT study | Fridericia QTc vs placebo at 1 h |
|---|---|
| Vardenafil 10 mg | +8 msec (6 to 9) |
| Vardenafil 80 mg | +10 msec (8 to 11) |
| Moxifloxacin 400 mg | +8 msec (6 to 9) |
09 Additive pairs that are not 'a little 10 mg instead'
Additive pairs that are not 'a little 10 mg instead' include other QT-prolonging drugs taken with any Levitra strength. The postmarketing combination study showed an additive QT effect compared with either drug alone. Dropping from 20 mg to 10 mg does not clear sotalol, amiodarone, or quinidine.
Moxifloxacin 400 mg was the active control in the 59-man study and raised Fridericia QTc 8 msec, the same band as vardenafil 10 mg. That comparison is why the shifts look 'small' and why the named avoidance groups still exist. A clinic does not use that table as permission to stack two QT-active drugs.
Uncorrected QT in that study moved minus 2 msec at both vardenafil doses because heart rate rose 5 to 6 beats per minute. Correction method matters. Do not pick the friendliest column at home.
Macrolides, some antipsychotics, and methadone can sit on the same problem list. Bring the box, not a memory of 'the heart tablet.' A normal ECG last year does not cancel this year's new class III drug.
If the visit is really about a food-proof weekend, tadalafil avoids this vardenafil QT paragraph. That swap is a clinician pick the week an antiarrhythmic starts, not a self-swap at 22:00.
10 Put the antiarrhythmic names before the word peak
Put the antiarrhythmic names before the word peak. Elise Moreau reviewed this margin on 21 August 2026.
Class IA or class III drugs are an avoid line at 10 mg and at 20 mg. A watch trace is travel material, not the screen. Ritonavir breaks the 20 mg dose row before QT is the headline. Nitrates stay banned after a clean interval. A normal ECG does not skip the 10 mg start.
Interval-page questions go to [email protected]. Not an ECG read. A normal tracing does not skip the 10 mg start. Class III remains an avoid line at both strengths.