QT first, then the milligram ladder
Do not take vardenafil with congenital QT prolongation or with Class IA or Class III antiarrhythmics. Chest pain after a dose is emergency care, not a faster tablet next time.
Usual adult start is 10 mg about 60 minutes before sexual activity. The labeled range is 5 to 20 mg, plus a 2.5 mg tablet for inhibitor and special-population math. Frequency is once daily.
Reviews that open with 'fastest PDE5' skip the electrophysiology section. Therapeutic 10 mg and supratherapeutic 80 mg vardenafil moved QTc in a 59-man study on a scale similar to moxifloxacin 400 mg. That is why this card reads QT before it rates onset.
Scan congenital QT and the antiarrhythmic list. Tag ritonavir and other CYP3A4 blockers. Board-check age 65 and alpha-blockers. Post the milligram last.
QT-first review chip
Fast peak, thin bioavailability
Absolute bioavailability is about 15%. Fasted Tmax after 20 mg usually lands between 30 minutes and two hours, median 60 minutes. PK is roughly dose-proportional across the labeled range.
Clearance is about 56 L/h. Terminal half-life of parent and primary metabolite M1 is about 4-5 hours. Metabolites leave mostly in feces (about 91-95%) with little in urine (about 2-6%).
CYP3A4 does most of the work; CYP2C isoforms chip in. That split is why ritonavir, which also hits CYP2C9, produced the ugliest fold-rise in the interaction table.
| Absorption | Fasted Tmax 30-120 min (median 60); bioavailability ~15%. |
|---|---|
| Distribution | Rapid distribution; orange film-coated 2.5-20 mg tablets. |
| Metabolism | Mainly CYP3A4, minor CYP2C; M1 active metabolite. |
| Excretion | T1/2 ~4-5 h; feces 91-95%, urine 2-6%. |
Internet strips and the QT miss
Untraced mail-order strips skip the board-check that would have caught amiodarone. Counterfeit PDE5 is a recurring public-health theme in this city. A cheap 20 mg tablet that never saw a DIN is not a rating of generic vardenafil.
Legitimate telehealth still owes the same QT and CYP3A4 reconciliation as a Bay Street visit. If the intake form had no antiarrhythmic box, that is a process failure, not permission. Mail the clinic, not [email protected], about your chart.
Travel blisters that bake in a glove box can degrade like any oral tablet. Do not dose a melted film-coat and then blame QT screening when the evening fails. Cabin-temperature travel is ordinary; a dashboard in August is not.
The 59-man QT study, in review
Investigators gave 10 mg and 80 mg vardenafil, placebo, and moxifloxacin 400 mg to 59 healthy men aged 45-60 (81% White, 12% Black, 7% Hispanic). They read QT at one hour because that time matches average peak concentration.
Eighty milligrams is four times the labeled ceiling. They picked it to cover concentrations seen when 5 mg vardenafil meets ritonavir 600 mg twice daily. Fridericia QTc rose about 8 msec on 10 mg and 10 msec on 80 mg versus placebo; individual correction gave about 4 and 6 msec. Moxifloxacin sat in the same band.
Heart rate rose about 5 beats/min on 10 mg and 6 on 80 mg versus placebo. A later study that combined Levitra with another QT-active drug showed an additive effect. Reviews that say 'tiny QT, ignore it' are not reading those rows.
| Arm (1 h post-dose) | Fridericia QTc vs placebo | Heart rate |
|---|---|---|
| Vardenafil 10 mg | +8 msec (6-9) | +5 bpm |
| Vardenafil 80 mg | +10 msec (8-11) | +6 bpm |
| Moxifloxacin 400 mg | +8 msec (6-9) | Active QT control |
High-fat meals cut Cmax eighteen to fifty
Two food-effect studies are in the label. High-fat meals reduced Cmax by 18% to 50%. The tablet may still be taken with food, but the 60-minute median is a fasted story.
Men who chase Levitra for speed and then swallow it after fries are running the wrong review. If dinner always wins, sildenafil has a cleaner published 29% Cmax cut, and tadalafil is the food-light long window.
Alcohol is a hypotension stack, not a QT fix. Cottage hot-tub plus wine plus first-dose 10 mg is a faint pattern this board sees every summer. It is not an arrhythmia until it is - sit down first, then get checked if you blacked out.
Age sixty-five and the five-milligram start
Label language asks clinicians to consider 5 mg as the first tablet at 65 and older. The 10 mg 'most patients' sentence is not a senior default.
Moderate hepatic impairment often lands on a 5 mg conversation as well. Severe hepatic or renal stories need the full leaflet, not a forum average. This board will not invent a Child-Pugh shortcut.
Stimulation is still required. A 5 mg tablet that 'did nothing' on the couch with no arousal is not a failed rating. Try the same milligram with a real attempt before the prescriber moves to 10 mg.
NAION, hearing, and the four-hour erection still apply
QT is the differentiator on this card. It does not retire the rest of the PDE5 warning set. Sudden vision loss, sudden hearing change, and an erection past four hours still stop the tablet and start a care visit.
NAION language for the class includes prior events and crowded discs. Benefit must outweigh recurrence risk if a clinician still offers vardenafil after a first NAION. That conversation is ophthalmology plus the prescriber, not a faster 20 mg to 'get it over with.'
Priapism caution matches the class: anatomic deformity, sickle cell disease, myeloma, leukemia. A QT-clear ECG does not clear those tags. Do not combine leftover daily tadalafil with a Saturday Levitra just because the ECG was normal on Friday.
Class warnings QT does not replace
- Stop for sudden vision or hearing change.
- Four-hour erection: urgent urology.
- Nitrates remain contraindicated, QT or not.
- Do not stack two oral PDE5 drugs.
Generic orange versus brand crosses
Brand Levitra tablets are orange, round, film-coated, with a Bayer cross and a 2.5, 5, 10, or 20 mark. Generics may drop the cross and change the shade. The QT study, the 15% bioavailability, and the CYP3A4 caps do not change with the logo.
Men who 'rate' brand as faster after a product swap usually changed dinner or anxiety the same week. Ask the pharmacist for the DIN and keep a two-night log before you demand 20 mg. A cosmetic dye reaction is a reason to swap manufacturers, not a reason to skip the ECG.
Ontario formulary tiers move. A cheaper generic does not shorten the amiodarone avoid. If the window only stocks 20 mg and the script says 2.5 mg, do not quarter a 20. These tablets are not a licensed split on this board.
Class IA and III drugs that close this panel
Quinidine and procainamide (Class IA) and amiodarone and sotalol (Class III) are named avoids, together with congenital QT prolongation. This is not a 'monitor and proceed' shrug on the Levitra label.
Other QT-active drugs still deserve a clinician look even when they are not in that short list. The additive postmarketing study is the reason. Psychiatry lists (some antipsychotics, high-dose citalopram) belong on the same printout as the ED script.
A family history of sudden death under age 50 is a reason to obtain an ECG before a first PDE5 trial if one is not already on file. Syncope after the first 10 mg is a stop, not a 5 mg hobby.
Close-the-panel tags
- Avoid: congenital long QT.
- Avoid: quinidine, procainamide.
- Avoid: amiodarone, sotalol.
- Bring every QT-active name, including 'as needed' antibiotics.
2.5 mg when CYP3A4 is blocked
Ritonavir is the extreme: 49-fold AUC, 13-fold Cmax, half-life about 26 hours. Cap: 2.5 mg once in 72 hours. Indinavir 800 mg three times daily with 10 mg vardenafil: 16-fold AUC, 7-fold Cmax, doubled half-life. Cap: 2.5 mg in 24 hours.
Ketoconazole 200 mg daily with 5 mg vardenafil: 10-fold AUC, 4-fold Cmax. Cap: 5 mg in 24 hours. Ketoconazole 400 mg daily: cap 2.5 mg in 24 hours. Erythromycin shares the 5 mg / 24 hour cap.
Those 2.5 mg tablets are why the Sephira range lock starts at 2.5 and runs to 20. Reviews that never mention 2.5 mg are written for men on no inhibitors.
| Inhibitor | Vardenafil cap |
|---|---|
| Ritonavir | 2.5 mg once / 72 h |
| Indinavir, saquinavir, atazanavir, clarithromycin, keto 400 mg, itra 400 mg | 2.5 mg / 24 h |
| Ketoconazole 200 mg, itraconazole 200 mg, erythromycin | 5 mg / 24 h |
| No inhibitor, typical adult | 10 mg start; 5-20 mg |
Published boards for the low start and the 20 mg pack
The insert quotes GoodRx 2.5 mg x 30 and 20 mg x 10. Those are the sourced cells. A 10 mg thirty-count dollar is not on this card.
High 2.5 mg retail prints do not mean the low tablet is 'special.' They mean list price. Ask the window. QT still comes first.
Generic vardenafil 2.5 mg through 20 mg is the Sephira range lock, August 2026. GoodRx lists 2.5 mg x 30 at $1,100.46 / $289.61 and 20 mg x 10 at $573.78 / $44.21 (06 July 2026). Sephira does not dispense.
How honest onset reviews should read
Median Tmax at 60 minutes is a population number. Individuals land anywhere from 30 minutes to two hours even fasted. A man who rates Levitra 'slow' at 40 minutes may simply be early on his own curve.
High-fat Cmax cuts of 18-50% can erase the speed story that made someone pick this molecule over sildenafil. If the point of the switch was dinner-proof timing, tadalafil's food-light label is the cleaner comparison, once nitrates and QT are sorted.
Stimulation is required. A 10 mg tablet on the nightstand during a movie is not a failed onset trial. Log a real attempt, a plate note, and the swallow time. Two such evenings beat a one-line star rating.
Orange Bayer-cross tablets and generic rounds can look different in a palm. Debossed 2.5, 5, 10, or 20 should match the script. A 20 mg tablet taken as 'two 10s' is a double dose if you already swallowed 10 mg.
Alpha-blockers and standing systolic outliers
Forced-titration work with terazosin 10 mg (n=29) and tamsulosin 0.4 mg (n=24) in men 45-74 produced hypotensive withdrawals (2 on terazosin, 4 on tamsulosin) and standing SBP outliers (19/29 and 9/24). Simultaneous Tmax with terazosin ended that arm early.
Start the alpha-blocker first and reach a stable dose. Then start vardenafil at 5 mg if a clinician still wants this class. Separate dosing times when asked. First-dose evening should be quiet, seated, and light on alcohol.
BPH-plus-ED men sometimes want daily tadalafil 5 mg instead of a fast vardenafil peak plus an alpha-blocker. That is a regimen choice, not a QT loophole.
Post the QT tag, then compare
Vardenafil earns a place when a short tail and a one-hour median matter and the ECG is clean. It loses when amiodarone, congenital QT, or a brutal CYP3A4 inhibitor sits on the same list.
Compare food-heavy evenings on sildenafil and long clocks on tadalafil. Dr. Yuki Tanaka reviewed this panel on 2026-08-21. Corrections: [email protected].