Twenty milligrams after the ECG, not before
Brynza locks vardenafil on 20 mg - the labelled ceiling tablet, not Staxyn ODT. The first filter is still the QT note, because 20 mg is a poor surprise in a man on amiodarone.
A thorough QT study in healthy men saw small QTcF increases: about 8 ms after vardenafil 10 mg and about 10 ms after 80 mg, in the same range as moxifloxacin 400 mg. Absolute QT did not lengthen. The clinical meaning of those milliseconds is unknown, which is why labelling avoids the high-risk groups instead of shrugging.
Patients with congenital long QT, or on Class IA (quinidine, procainamide) or Class III (amiodarone, sotalol) antiarrhythmics, should not use vardenafil. A later study with gatifloxacin showed additive QTcF change (about 9 ms from baseline when 10 mg plus 400 mg gatifloxacin were combined).
| Filter | Action at 20 mg |
|---|---|
| Congenital long QT | Avoid |
| Quinidine, procainamide | Avoid |
| Amiodarone, sotalol | Avoid |
| Other QT-prolonging drugs | Prescriber weighs additivity |
| Clean ECG, no those drugs | Common AE list below applies |
A hot face at peak is not torsades
Flushing at 11% and headache at 15% arrive with the 20 mg peak. They are the common list. Syncope, a racing irregular pulse, or collapse after 20 mg is a different visit.
Fear-mongering that every Levitra night is a code blue is the opposite error from ignoring amiodarone. Hold the middle.
CK rose in 2%. A sore back after 20 mg is less of a tadalafil-pattern delayed lumbar story. Still mention unusual pain.
Rhinitis at 9% is not anaphylaxis. Lip swell and wheeze are. Do not confuse a stuffy peak with an airway emergency.
Nitrates still beat a perfect ECG. A man cleared for QT who starts GTN is back to contraindicated.
Staxyn ODT 10 mg is not a 'safer QT' 20 mg. It is another vardenafil form with its own food rules. Do not stack it with the film-coated 20 mg.
Eight milliseconds is a door, not a headline
A thorough QT study saw about 8 ms QTcF after 10 mg and about 10 ms after 80 mg, in the same neighbourhood as a moxifloxacin control. Absolute QT did not lengthen. Unknown clinical meaning is why labelling avoids congenital long QT and Class IA or III antiarrhythmics instead of shrugging. Quinidine, procainamide, amiodarone, and sotalol close the door. A watch flag is not congenital long QT. A real congenital diagnosis is not a watch rumour. Bring the ECG before the 20 mg foil.
Gatifloxacin plus 10 mg showed additivity near 9 ms. A fluoroquinolone week is a reason to wait on 20 mg unless cardiology already has the strip. Macrolides can sit on QT-active lists too. Dental clarithromycin plus Friday 20 mg is a stack this sidebar will not bless. Hypokalemia from a new 80 mg morning loop makes any QT story uglier. Check ions if someone insists on a weekend 20 mg while Lasix is new.
Staxyn ODT is not this 20 mg film-coated tablet. Do not convert ODT to film-coated by habit and do not stack them. Nitrates still beat a perfect ECG. Riociguat too. Women were not the thorough-QT population. Do not invent a partner 20 mg. Amiodarone stopped in 2023 can still linger. Cardiology dates the stop, not this thread.
Once the door is open, treat 20 mg as a PDE5 with headache 15%, flushing 11%, rhinitis 9%, and dyspepsia 4%, with a dose effect across 5, 10, and 20 mg. Fear that every Levitra night is torsades is the opposite error from ignoring amiodarone. Cut from 20 mg to 10 mg for flush may be reasonable - 10 mg was the therapeutic QT-study dose - and is still a prescription change. Parent: vardenafil column. Onset next door.
Once the QT door is open, the usual list
Pooled Levitra trials (N=2203 on drug) reported headache in 15%, flushing in 11%, rhinitis in 9%, and dyspepsia in 4% (placebo 4%, 1%, 3%, 1%). Dizziness 2%, nausea 2%, back pain on the common list, CK rise 2%.
Placebo-controlled work suggested a dose effect for headache, flushing, dyspepsia, nausea, and rhinitis across 5, 10, and 20 mg. The 20 mg lock is the loudest common-rung, not a different molecule.
Those percentages matter after the ECG is acceptable. They do not replace the QT filter. A man who passed the filter still deserves counsel on flush and stuffed nose.
Read the antiarrhythmic list before the 20 mg foil
Quinidine, procainamide, amiodarone, sotalol: avoid. Congenital long QT: avoid. That is the filter this sidebar exists to print before anyone talks about a 15% headache.
A thorough QT study saw about 8 ms QTcF after 10 mg and about 10 ms after 80 mg, similar to moxifloxacin. Absolute QT did not lengthen. Unknown clinical meaning is why labelling avoids high-risk groups instead of shrugging.
Gatifloxacin plus 10 mg showed additivity. A fluoroquinolone week is a reason to wait on 20 mg unless cardiology has the strip.
Hypokalemia from a new 80 mg loop makes any QT story uglier. Check ions if someone insists on a weekend 20 mg.
A watch flag is not congenital long QT. A real congenital diagnosis is not a watch rumour. Bring the ECG.
Staxyn ODT is not this 20 mg tablet. Do not convert ODT to film-coated by habit and do not stack them.
Nitrates still beat a perfect ECG. Riociguat too.
Common list after the door opens: headache 15%, flushing 11%, rhinitis 9%, dyspepsia 4%. Dose effect across 5-10-20 mg.
Small milliseconds are not a panic sheet
Therapeutic 10 mg and supratherapeutic 80 mg produced small QTc rises similar to a moxifloxacin control. That is a thorough-QT finding, not a ward epidemic of torsades in everyday 20 mg use.
Fear-mongering ('never Levitra') is the opposite error from ignoring amiodarone. This sidebar holds the middle: screen the groups the label names, then treat 20 mg like a PDE5 with a 15% headache rate.
Staxyn 10 mg ODT is not this tablet. Do not convert ODT to 20 mg film-coated by habit.
Other QT-active drugs add milliseconds
The gatifloxacin plus vardenafil 10 mg work showed additivity - about 9 ms QTcF from baseline when both were on board. Fluoroquinolones, some macrolides, and methadone are the everyday add-on questions.
A clean ECG last year does not bless 20 mg during a moxifloxacin week for pneumonia. Finish the QT-active course first unless cardiology has the strip and says go.
Hypokalemia from a new 80 mg loop (see the Lasix sidebars) can make any QT story uglier. Ions matter when someone insists on 20 mg 'this weekend'.
Women were not the thorough-QT population. This site's 20 mg lock is still a men's ED tablet in practice. Do not invent a partner dose.
Congenital long QT in a first-degree relative is a reason to ask for an ECG, not a smartwatch verdict and a 20 mg swallow.
If the man is already on sotalol, the answer is no - Class III stays an avoid. Do not 'use 5 mg instead' from this page.
Onset and class choice live elsewhere
How fast 20 mg peaks, and how food moves that peak, is the onset issue sidebar.
Versus tadalafil 2.5 mg daily and sildenafil 25 mg, use the PDE5 matrix. This page stays on QT plus the 20 mg common AE list.
A new loop plus 20 mg is an ion week first
Potassium 3.2 and a planned 20 mg night is not a Levitra question. Fix the ion with the team that owns the 80 mg furosemide. See the Lasix ion sidebar. Low K plus any QT-active plan is ugly. Salt substitutes, ACE tablets, and prescribed potassium can flip the same month from 3.1 to 5.8. List every bottle before anyone talks about a 15% headache.
CK rose in 2%. Unusual muscle pain still gets mentioned. Flush at peak is the 11% cell. Syncope and an irregular racing pulse are a different visit. Class choice versus tadalafil 2.5 mg daily and sildenafil 25 mg lives on the PDE5 matrix if the QT filter never opens. This desk does not clear QT by mail and will not invent a Levitra coupon.
Congenital long QT in a cousin is a family story until an ECG says otherwise. Do not withhold 20 mg from a clean list because a forum said 8 ms. Do not give 20 mg to a man on sotalol because a forum said 8 ms is tiny. Hold the middle. Screen the named groups. Then treat the common list.
Brynza lock remains 20 mg film-coated after the filter. A 5 mg or 10 mg cut is a chart change. Hidden GTN still contraindicates the night. Parent sheet: vardenafil column.
Nitrates still beat the ECG
A perfect ECG does not allow nitrates or riociguat. Those remain contraindicated for vardenafil as for the class.
Alpha-blockers need a stable dose. CYP3A4 inhibitors raise vardenafil; labelled cuts exist. Grapefruit is sloppy inhibition.
Priapism past four hours, sudden vision or hearing change - same emergency path as sildenafil. QT clearance does not shorten that list.
- Class IA / III or congenital LQTS - no vardenafil
- Nitrates / riociguat - no vardenafil
- One 20 mg film-coated tablet per day unless the label cuts it
- Staxyn ODT is a different issue
Neither panic sheet nor shrug
Fear that every Levitra night is torsades is the opposite error from ignoring amiodarone. Hold the middle: screen the named groups, then treat 20 mg as a PDE5 with a 15% headache rate.
Flush at peak is the 11% cell. Syncope and an irregular racing pulse are a different visit.
CK rose in 2%. Unusual muscle pain still gets mentioned.
Women were not the thorough-QT population. Do not invent a partner 20 mg.
Amiodarone stopped in 2023 still lingers. Cardiology dates the stop, not this thread.
Cut from 20 mg to 10 mg for flush may be reasonable - 10 mg was the therapeutic QT-study dose - and is still a prescription change.
Class choice versus tadalafil 2.5 mg daily and sildenafil 25 mg lives on the PDE5 matrix.
Parent: vardenafil column. Onset: onset issue.
20 mg is a ceiling with a filter
Bring the antiarrhythmic list, not a forum printout. If the list is empty and the ECG is old, the prescriber decides whether to refresh it.
Parent pharmacology: vardenafil column. Brynza does not clear QT by mail.
Sources
- DailyMed Levitra - QT study 10 mg vs 80 mg vs moxifloxacin; avoid congenital LQTS, Class IA/III
- Levitra AE table - headache 15%, flushing 11%, rhinitis 9%, dyspepsia 4%
- Postmarketing gatifloxacin additivity (~9 ms QTcF with 10 mg)
Checked against the current label and reviewed by Dr. Tomasz Krajewski. See Brief, Set, Proof, Issue.