Three cards, one start chip, a short brief
Enter the three-card spread. Annotate food and QT. Stamp 2.5 mg as a start, not a trophy. Close any sentence that turns this into a cart.
Bayer put Levitra on a US shelf in 2003. GSK co-marketed it. The chemistry was a deliberate PDE5 cousin, not a Sandwich accident.
Three PDE5 cards share a mechanism and a nitrate ban. They split on half-life, food, and how loudly the label talks about QT.
This brief compares clocks, meals, and that QT sentence. It will not rank 'best bedroom tablet' and it will not quote a cash window.
Two point five milligrams is this desk's locked start chip. Typical labeled starts sit higher. The small tablet exists for hepatic impairment, older age, and CYP3A4 caution - annotate that before anyone treats 2.5 as a flex.
Deep holds stay on the Levitra formulary page. Cousin discovery and half-life files live at sildenafil discovery and tadalafil clock notes.
Bayer built it; GSK helped put Levitra on shelves
German cardiovascular chemistry at Bayer produced vardenafil as a potent, selective PDE5 inhibitor meant to compete after Viagra had already taught the market the class.
Co-marketing with GSK put two sales forces on one brand. That is industrial history, not an efficacy endpoint.
US approval in 2003 sat in the same season as tadalafil. For a few years the three cards fought on onset, duration, and 'clean selectivity' language.
Potency talk in those years was a binding-affinity pitch. It did not rewrite IIEF the way a 24-week randomized ladder does, and this brief will not pretend it did.
Staxyn, the later orally disintegrating tablet, is a Bayer-family footnote with its own milligram story. It is not proof that Levitra 2.5 'melts too.'
Competing on 'cleaner selectivity' in 2003-2005 ads did not create a new primary endpoint. IIEF still sat in the same family as the sildenafil papers.
Industrial co-promotion explains why two logos appeared on early packs. It does not change a meal delay or a QT sentence.
Onset and fade versus the weekend pill
Vardenafil's half-life sits near four hours, in the sildenafil neighborhood, not in tadalafil's 17.5-hour country.
Onset can be useful inside an hour on an emptier stomach. Fade follows the short curve. There is no honest 36-hour nickname here.
Men who hate calendars and want a trough should read the 2.5 daily half-life study instead of forcing Levitra into a breakfast habit this brief does not support.
Men who want the original miss-then-hit story should read the sildenafil discovery file. Vardenafil was not a repositioned angina miss. It was a planned cousin.
Pick the clock first. Then pick the card. That order keeps this brief short.
2.5 mg is a labeled start, not a trophy dose
Typical labeled starts sit at 10 mg, taken as needed. 2.5 mg exists for people whose exposure will run high - hepatic impairment, older age, certain CYP3A4 inhibitors.
This desk locks 2.5 mg as SERP context so the lowest chip is visible. It is not a claim that 2.5 mg won the big IIEF ladders as the usual first tablet.
Ritonavir is the loudest studied CYP3A4 collision. Strong inhibitors turn a casual 10 mg into an exposure the 2.5 mg chip was meant to respect.
Alpha-blockers need spacing and a stable dose on both sides. That is shared class work, not a Levitra-only stunt.
I will not let a 'lowest start' lock get misread as 'weakest drug.' It is a caution chip.
Hepatic impairment raises exposure because the tablet is cleared through CYP3A4 and the liver. That is why 2.5 mg exists as a labeled start, not as a lifestyle size.
Older age can land on the same small chip for the same exposure reason. Youth plus a clean CYP list usually does not.
The QT footnote the cousins do not share the same way
A crossover in 59 healthy men aged 45-60 put vardenafil 10 mg and 80 mg against moxifloxacin 400 mg. Mean QTc rose on the order of 8 to 10 msec - in the same neighborhood as the active control.
Sildenafil 50 and 400 mg sat in a related QT design. Small mean bumps appeared there too. The clinical meaning of those millisecond shifts is still described as unknown.
Levitra's US label tells patients with congenital QT prolongation, or those on class Ia or class III antiarrhythmics, to avoid the tablet. Tadalafil and sildenafil labels do not carry that same avoid-sentence.
A later add-on study with gatifloxacin showed a few extra milliseconds when either vardenafil 10 mg or sildenafil 50 mg was stacked on a QT-active antibiotic. Additive, not theatrical.
No torsade story has made this class famous. I still stamp the avoid-list on vardenafil because the label wrote it, not because I am inventing a unique arrhythmia epidemic.
Moxifloxacin sat in that crossover as an active control so a flat QT line could not be blamed on a sleepy assay. The bump was real and small.
Class Ia names on the avoid-list include quinidine and procainamide. Class III includes sotalol and amiodarone. I write those names, not just 'heart drugs.'
A fatty meal delays vardenafil more than tadalafil
High-fat food can push vardenafil's peak about an hour later and shave Cmax. That is a labeled PK mark, not a lifestyle lecture.
Tadalafil's integrated healthy-subject work kept food inside the usual bounds. If a man wants a meal and a tablet in the same hour, that cousin's curve is quieter.
Sildenafil also loses peak to a heavy plate - the empty-plate habit on this site's 100 mg lock exists for that reason. Vardenafil sits closer to that short-clock meal story than to tadalafil.
I annotate the dinner before I stamp 'vardenafil failed.' A steak plus a 2.5 mg caution chip is a stacked delay, not a class indictment.
Alcohol remains a hypotension stack, not a unique vardenafil PK villain.
Empty-ish timing is the practical annotate step on a Saturday. I would rather move the swallow than invent a 2.5 mg 'food-proof' claim this brief does not have.
Cousins that ignore dinner are using tadalafil's curve, not Levitra's. Do not import that quiet-meal finding onto a Bayer chip.
Staxyn is not the same milligram story
The orally disintegrating tablet was built for men who dislike swallowing or want a quieter bottle. It is not a lozenge version of every Levitra milligram.
Bioavailability and peak are not a one-to-one swap with a 10 mg film-coated tablet. Treating them as identical is how a comparison brief becomes a dosing error.
Food and water instructions differ. I will not collapse them into 'just melt it.'
This site's 2.5 mg lock is a film-coated start chip. It is not a Staxyn strength and I will not pretend it is.
If discretion is the only reason for the melt tablet, say that out loud so nobody 'converts' milligrams in the kitchen.
Where the three clocks actually differ
- Shared: PDE5, sexual stimulation required, nitrate hard stop.
- Split: meal delay (var/sil > tad), daily trough (tad only), QT avoid-sentence (var label).
- 2.5 mg on this desk: caution start, not the usual IIEF ladder chip.
- Staxyn: separate milligram story, not a melt-Levitra-2.5.
Half-life: tadalafil ~17.5 h; sildenafil and vardenafil ~4 h. Only the long curve supports a true daily ED trough.
Food: tadalafil stays quiet; sildenafil and vardenafil lose peak to a heavy plate. Empty-plate habits belong to the short clocks.
QT sentence: vardenafil's label avoids congenital long QT and class Ia/III antiarrhythmics. The cousins do not print that same avoid-line.
Origin: sildenafil is a Sandwich miss; tadalafil is a designed long curve; vardenafil is a Bayer cousin built to compete. Origin is not an IIEF score, but it explains why this brief exists.
Nitrates: all three closed. Wait clocks differ because the curves differ - about a day on the short cards, about two on tadalafil.
Selectivity posters from the launch years do not outrank those four splits. I keep potency talk in a footnote, not in the stamp line.
Riociguat joins nitrates as a shared hard stop across the three cards. A small 2.5 mg chip does not buy an exception.
How a comparison brief gets stamped
Write the shared hard stop first so nobody thinks a 'winner' escapes nitrates.
Write the meal difference second. That is the counseling mark men actually feel on a Saturday night.
Write the QT avoid-sentence third, with the millisecond study attached, without inventing torsade counts.
Write 2.5 mg as a caution start. Refuse trophy language.
Close the price question. This brief has no fill table and no coupon caption.
What this brief keeps
Levitra is a Bayer/GSK cousin with a short clock, a meal delay, and a QT avoid-sentence the other two labels do not copy the same way.
Two point five milligrams is a start chip for high-exposure situations, not the usual first IIEF tablet and not a Staxyn melt.
Pick tadalafil when the question is a trough or a quiet meal. Pick the short clocks when the question is a planned hour. Pick vardenafil only after the QT list is clean.
Bring the antiarrhythmic list and the dinner plan to a clinician who can see you. THL-S04 is a brief, not a bottle.
Talk with your own clinician or pharmacist before you change a tablet or a dose. Open the ledger disclaimer.
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