01Usual start is 10 mg, about an hour out
Pick 10 mg as the usual start. Check QT and CYP. Tag Staxyn as another fill. Bin any plan that opens at 2.5 mg without a labelled reason.
Bayer's most-patient sentence is 10 mg orally, as needed, about 60 minutes before sexual activity. Rise to 20 mg or drop to 5 mg on effect and side effects. Once per day. That 10 mg line is the Kaelis lock. A 2.5 mg tablet belongs to the CYP table, not to a timid first night without a flag.
Sexual stimulation is required. The tablet does not supply desire. Say it once, then move to the checks that actually close this bin: nitrates, riociguat, congenital QT, class IA or III antiarrhythmics, and a second PDE5.
Staxyn is vardenafil 10 mg as an orally disintegrating tablet. Different fill, different handling, not a casual swap for film-coated Levitra 10 mg. This card files the film-coated 10 mg start.
Dr. Priya Natarajan tagged this bin on 21 August 2026. Source mail only: [email protected]. The desk does not sell tablets and does not replace a GP. Bring the rest of the medicine list, including anything taken 'only when the chest is tight'.
02Why the QT study used 80 mg if the lock is 10 mg
Eighty milligrams is four times the highest recommended Levitra dose. The QT protocol picked it because those plasma levels cover a low 5 mg tablet taken with ritonavir 600 mg twice daily. Ritonavir was the largest CYP3A4 interaction they had measured.
Read that the other way: a 'small' 5 mg next to ritonavir can look like an 80 mg exposure. That is why the ritonavir cut is 2.5 mg in 72 hours, not a shrug and a usual 10 mg start. The lock yields when that partner arrives.
Moxifloxacin 400 mg sat in the same crossover as the active control. Similar QTc movement at 10 mg and at 80 mg does not make 10 mg a toy. It tells you the class effect is measurable at the usual start. Congenital QT and class IA or III drugs still close the bin.
Hospital ECGs after a first 10 mg should note the swallow time. One hour is near Tmax, which is when the study measured. A tracing at six hours answers a different question. Write the clock on the request. Mean heart rate rose about 5 beats per minute after 10 mg versus placebo in that crossover. Palpitations at one hour are not a reason to redose.
Family QT stories and unexplained syncope belong on the same checklist as the medicine list. A normal office ECG last year does not clear a new class III drug started last month. Recheck before this 10 mg lock opens. An add-on macrolide the same week also reopens the CYP table and can force a 2.5 mg cut until that antibiotic course ends.
Borrowed 'Levitra' from a stag night fails the same check as a nameless blister. Strength may be wrong. Extra PDE5 may sit in the tablet. Next to a nitrate drawer that is an admission.
03Age 65 and a tired liver move the start off this 10 mg lock
Consider 5 mg at 65 and over. That sentence is on the insert, not a Kaelis invention. Moderate hepatic impairment: do not exceed 10 mg. Severe hepatic disease is a poorer candidate for any vardenafil start. This lock is the usual adult 10 mg, not a promise that every older man keeps it.
Alpha-blocker plus age plus a CYP3A4 inhibitor is how 10 mg becomes the wrong first tablet. Start 5 mg, or 2.5 mg when the CYP table says so. Standing pressures. Slow stand. No same-night debut of both drugs.
Once-daily is the ceiling. A midnight second 10 mg is not labelled rescue. If the first 10 mg failed at twenty-five minutes, the clock was early. If it failed at two hours after a heavy plate, Cmax may have been cut. Audit those before anyone writes 20 mg.
PAH PDE5 products are a different bin. Do not add Levitra on top of a pulmonary sildenafil or tadalafil regimen. Reconcile first. The PDE5 matchup is for choosing one cousin, not stacking three. A borrowed film coat next to Adcirca or Revatio is the same class mistake with a different brand name.
Ask the window to price eight of 10 mg. The published GoodRx line in the fill is a thirty-count. This desk does not invent an eight-count retail cell. Staxyn stays off that quote. A regulated generic 10 mg film coat matches the INN; a nameless blister from a group chat does not.
Condoms and STI talk still belong in the same visit. Levitra does not replace that. A new partner is a reason to say it out loud. Medical checks stay first. Social checks stay second. Both get tagged before the bin opens.
04Staxyn 10 mg ODT is a different fill from this film-coated 10 mg
People see 'vardenafil 10 mg' and assume every 10 mg is this bin. Staxyn dissolves on the tongue. Handling, water, and some kinetic details differ. Do not substitute ODT for film-coated Levitra because the milligram number matches. Ask the window for the form that was prescribed.
Flexible-dose Levitra trials started men at 10 mg and allowed a drop to 5 mg or a rise to 20 mg. That titration is the labelled personality of this start. Headache, flushing, rhinitis, and dyspepsia led the common list and rose across 5, 10, and 20 mg.
Compare columns with sildenafil on the PDE5 matchup when the argument is food versus QT versus a long tail. Do not swallow two class members to 'cover gaps'.
GoodRx dollars for a thirty-count 10 mg board live in the fill under this closer. This bin asks the window to price eight of 10 mg. Do not invent an eight-count retail cell. Staxyn is a different price line.
| Situation | Labelled vardenafil | This bin |
|---|---|---|
| Most patients | 10 mg ~60 min before activity | Lock: 10 mg usual start |
| Age ≥65 | Consider 5 mg start | Not the 10 mg lock |
| Stable alpha-blocker | Start 5 mg (2.5 mg with some 3A4 inhibitors) | Do not open at 10 |
| Ritonavir | 2.5 mg, not more than once / 72 h | 2.5 is a cut, not a vibe |
| Staxyn ODT 10 mg | Different product | Do not swap by milligram |
05Nitrates close it; alpha-blockers step the start down to 5 mg
Organic nitrates and nitric oxide donors stay contraindicated. The disease state that needs a nitrate already raises hypotension risk. Do not 'time' a spray around a 10 mg Levitra tablet at home.
Alpha-blockers plus vardenafil can drop standing pressure. Patients should be stable on the alpha-blocker first. Then start Levitra at 5 mg, not this 10 mg lock. Separating Tmax by about 6 hours reduced some of the ugly standing readings in a terazosin study; simultaneous peaks looked worse. That is a pharmacology detail, not a home scheduling trick.
Men already on an optimised PDE5 dose who then start an alpha-blocker should start the alpha-blocker low. Other antihypertensives still add orthostasis. Counsel the slow stand.
Riociguat and any other PDE5 inhibitor stay off the card. One class member. Fitness for sex still precedes any 10 mg conversation after a recent infarct or unstable angina.
Cuts and closes on the 10 mg usual-start bin
- Absolute: nitrates, NO donors, riociguat, other PDE5 drugs
- Avoid: congenital QT; class IA or III antiarrhythmics
- Ritonavir: 2.5 mg / 72 h
- Several strong 3A4 partners: 2.5 mg / 24 h
- Erythromycin or keto/itra 200 mg: 5 mg / 24 h
- Stable alpha-blocker: start 5 mg, not 10
06Common noise versus the stop list
Headache, flushing, rhinitis, and dyspepsia are the everyday list and they climb with milligrams. Nausea shows up. A stuffy nose is not an allergy until something else is. Warn before the first 10 mg so a man does not abandon the class after one flush.
Sudden vision loss: stop and seek care. NAION is the class concern, same logic as the cousins. Sudden hearing change: same stop. Erection past four hours: emergency. Predisposing blood disorders and penile deformity need a look before the first swallow.
Chest pain during activity is ischaemia until a clinician says otherwise. No nitrate rescue while vardenafil is on board. Palpitations in a man with a QT story belong in clinic, not in a second 10 mg experiment.
Unmarked internet 'Levitra' is a verification failure. Strength may be wrong. Extra PDE5 may be present. That pair next to a nitrate drawer is how a cheap tablet becomes an admission.
07The QT pass opens or closes this 10 mg bin
A crossover study in 59 healthy men aged 45 to 60 compared vardenafil 10 mg, vardenafil 80 mg (four times the highest recommended dose), placebo, and moxifloxacin 400 mg. QT was read at one hour, near typical peak. Therapeutic 10 mg and supratherapeutic 80 mg produced QTc increases similar to the moxifloxacin control.
Heart rate rose a mean of 5 beats per minute after 10 mg versus placebo, and 6 beats after 80 mg. A later postmarketing combination study showed an additive QT effect when Levitra sat with another QT-active drug.
Men with congenital long QT, or men on class IA or class III antiarrhythmics, should avoid Levitra. That is a close, not a hedge. Amiodarone, sotalol, quinidine, procainamide: this bin stays shut. The QT pass clip is the short version for a busy chart.
A 10 mg start is not a reason to skip the ECG conversation in a man with syncope, a family QT story, or a recently added antiarrhythmic. Palpitations after the first tablet: hold further doses until someone looks.
08Sixty minutes is the labelled ask, not a two-minute hope
Median Tmax in the fasted state is 60 minutes. Mayo's patient page says the medicine usually begins to work within 60 minutes. Men who swallow 10 mg at the restaurant door and expect a response with coffee are early. The lead-time clip exists because that mistake is common.
Levitra can be taken with or without food. Two food-effect studies showed high-fat meals cut Cmax by 18% to 50%. Extent may hold up better than peak. A heavy plate can still make a 10 mg try look like a dud at forty minutes.
Half-life of vardenafil and its primary metabolite M1 is about 4 to 5 hours. This is a short-window PDE5, closer to sildenafil than to tadalafil. If the complaint is a whole Saturday without a clock, daily tadalafil 5 mg is the other card.
Maximum frequency is once per day. A second 10 mg at midnight is not a labelled rescue. If 10 mg failed, audit food, stimulation, and partners before anyone jumps to 20 mg.
09Fifteen percent bioavailability, then a hard CYP table
Vardenafil is rapidly absorbed. Absolute bioavailability is about 15%. Kinetics are roughly dose-proportional across the labelled range. Clearance is about 56 L/h. Metabolites leave mainly in faeces (about 91-95% of an oral dose) and little in urine (about 2-6%).
CYP3A4 does most of the work. CYP2C isoforms contribute. Ritonavir is the ugliest partner studied: a single 2.5 mg Levitra tablet should not be exceeded in a 72-hour period. Indinavir, saquinavir, atazanavir, ketoconazole 400 mg daily, itraconazole 400 mg daily, and clarithromycin: 2.5 mg in a 24-hour period.
Ketoconazole 200 mg daily, itraconazole 200 mg daily, and erythromycin: no more than 5 mg in 24 hours. Those cuts are why 2.5 mg exists on the shelf. They are not a reason to start an otherwise healthy man at 2.5 mg and call it 'cautious'.
Age 65 and over: consider a 5 mg start. Moderate hepatic impairment: do not exceed 10 mg. Severe hepatic impairment is a poorer candidate. Alpha-blocker, now stable: start Levitra at 5 mg (2.5 mg if certain CYP3A4 inhibitors sit on the same list).
| Absorption | Oral; bioavailability ~15%; Tmax median 60 min fasted; high-fat Cmax -18% to -50%. |
|---|---|
| Distribution | Distributed; metabolised extensively (M1 active-ish, shorter story than parent). |
| Metabolism | Mainly CYP3A4, minor CYP2C; ritonavir is the largest studied interaction. |
| Excretion | CL 56 L/h; t½ ~4-5 h (parent and M1); ~91-95% faeces, ~2-6% urine as metabolites. |
10Tag 10 mg usual start, then bin a 2.5 mg 'just in case' opener
Keep 10 mg as the usual start when QT is clean, CYP is quiet, and no nitrate sits in the house. Use 5 mg or 2.5 mg when the insert says so. Price eight, not a guessed thirty, in the fill below. Leave Staxyn on its own card when the script names an ODT.
Bring the ECG story and the antiviral list to the same visit. A usual start is only usual when those checks are done. This page does not write the script. It files the 10 mg lock so a 2.5 mg 'just in case' opener does not become the default without a labelled reason.
Reviewed 21 August 2026, Dr. Priya Natarajan. [email protected] for sources. Your clinician still owns the change.
Generic vardenafil 10 mg, eight tablets, the Kaelis usual-start lock, August 2026. GoodRx Levitra table lists 10 mg x 30 at $1,707.00 average retail and $76.31 with a coupon (06 July 2026). Staxyn 10 mg ODT is a different fill. Kaelis does not dispense.