Start on the 50 mg rung, then move with a reason

01The first rung is written as 50 mg

For most patients, the recommended dose is 50 mg taken as needed, about one hour before sexual activity. That is the opening sentence of the US dosing chapter. It is also this site's lock.

Based on effectiveness and toleration, the dose may be increased to a maximum of 100 mg or decreased to 25 mg. Maximum frequency is once per day. There is no labelled 150 mg and no labelled same-evening booster.

Blue diamond folklore about 'start high' is leftover brand advertising, not the 2020s generic label. Bring honest attempt notes to the visit. Factual corrections: [email protected].

Plasma at 24 hours after a 100 mg dose in healthy volunteers was about 2 ng/mL versus a peak near 440 ng/mL. That leftover is why a next-day tablet is usually acceptable on the frequency rule and why nitrates are still a problem the morning after. Age, cirrhosis, low GFR, and erythromycin left 3 to 8 times more sildenafil at 24 hours than healthy controls.

Those 24-hour leftovers are also why a 'failed' 50 mg Friday is not a reason to take 100 mg at Saturday breakfast. Wait the day. Change the plan at a visit.

02Who opens at 25 mg instead

Age over 65 raised AUC about 40 percent. Cirrhosis raised it about 80 percent. Creatinine clearance under 30 mL/min raised it about 100 percent. The PI says a 25 mg starting dose should be considered in those groups.

Potent CYP3A4 inhibitors (ketoconazole, itraconazole, erythromycin) also raise levels. Erythromycin increased AUC 182 percent in the cited work. Saquinavir 210 percent. Those are reasons to start low, not to skip the drug without a clinic sentence.

Ritonavir is its own row: 4-fold Cmax, 11-fold AUC, and a maximum single dose of 25 mg in a 48-hour period. Do not invent a 50 mg 'just this once' on that antiviral.

Cimetidine, a nonspecific CYP inhibitor, also raised sildenafil levels in the labelled interaction set. It is not ritonavir, but it belongs on the list when someone is already near a 25 mg start for age or GFR. Pile-ups are how a 'usual 50' becomes a loud first night.

03Rare events that close every rung

NAION and sudden hearing loss sit in the warnings for this class. They are uncommon. They are not a reason to skip a labelled 50 mg start in a man with a clean eye history. They are a reason to stop and call the same day if vision or hearing drops after a dose.

A crowded disc at risk for NAION is an ophthalmology sentence, not a forum sentence. If that history exists, the first rung may never be offered. Do not climb to 100 mg hoping a stronger tablet will be kinder to the optic nerve. Higher exposure is the wrong direction.

Priapism past four hours closes the ladder until urology says otherwise. Peyronie's disease or a deformed penis belongs on the intake before the first 50 mg, because a prolonged erection in that anatomy is a worse problem. The PI asks clinicians to look for those anatomies.

None of those rare stops license a kitchen 25-to-100 experiment. They license a phone call. Keep the attempt diary so the clinic can tell a meal miss from a vascular miss from a safety stop. The parent page is still the sildenafil letter.

04What to bring so the climb is not a guess

Three dated attempts: plate contents, alcohol, lead time, whether stimulation was present, what side effects showed up. A photo of the current blister. The full list, including borrowed tablets.

Vague 'it never works' leads to 100 mg by default. Dated attempts lead to a meal fix, a 25 mg drop, or a real climb. The clinic owns the order.

• 50 mg is the usual first step - 100 mg is not a default first pill
• 25 mg start when age, liver, kidneys, or listed CYP partners apply
• Once per day; no midnight rescue tablet
• Ask pharmacy for the written strength instead of splitting at home

05Splitting tablets is a pharmacy question

Some generics are scored. Many brand diamonds are not. A kitchen knife does not create a labelled 25 mg from a 50 mg tablet unless the pharmacist says that product may be split.

If the clinic wants 25 mg, the clean path is a 25 mg blister. If the clinic wants 100 mg, the clean path is a 100 mg blister. Improvised halves belong in the counselling note as a last resort, not a habit.

Do not combine leftover 25 mg and 50 mg tablets to 'fine-tune' 75 mg. That strength is not on the US tablet list.

Chewable or compounded sildenafil is a different product. This ladder is the 25, 50, and 100 mg film tablets. Do not assume a compounded 40 mg is a labelled rung.

06Side effects that mean stay, not climb

Flushing, headache, dyspepsia, and nasal congestion are the common on-label complaints. They often fade. They are not a reason to jump to 100 mg in hope the next rung will be quieter. Higher exposure usually means more of the same.

An erection lasting more than four hours needs emergency care. Sudden vision or hearing change needs the same day. Those events close the ladder until a clinician reopens it.

Nitrates and riociguat close the ladder before the first rung. Alpha-blocker combinations need a stable blood-pressure regimen and often a 25 mg start. Do not climb while those partners are still moving.

07One tablet per calendar day

The maximum recommended dosing frequency is once per day. A missed evening is not rescued by a 03:00 second tablet. A late dinner is not rescued by a second 50 mg.

If the relationship needs coverage on consecutive nights, a longer-window molecule may fit better than nightly sildenafil. That is a tadalafil conversation, not a homemade every-night 50 mg habit without a review.

Keep one PDE5 pathway. Switching from 100 mg sildenafil to vardenafil still needs a gap and a QT look. See the versus sheet.

08Climbing to 100 after honest attempts

Honest means more than one evening, with stimulation, without a heavy wine stack, and after at least one trial that respected the meal clock. See the food-delay note if every failure followed a creamy main.

If 50 mg works but headache or flush is miserable, the move is often down to 25 mg, not up. Toleration is half of the titration sentence. Efficacy is the other half.

One hundred milligrams is the labelled ceiling, not a masculinity proof. Ask the pharmacy for a 100 mg tablet if that is the written dose. Swallowing two 50 mg tablets to improvise 100 mg muddies the count and the side-effect diary.

RigiScan work showed hardness generally increased with dose and plasma concentration. That is a reason a clinic may write 100 mg after clean 50 mg misses. It is not a reason to start there. Side-effect incidence also tracks exposure. Headache at 50 mg often gets louder at 100 mg, not quieter.

Keep the same pharmacy when you climb so the imprint and the count stay readable. Switching generics the same week you change milligrams makes the diary argue with itself. One variable at a time.

09The ladder closes at the clinic

Stay on 50 mg until a dated diary says otherwise. Drop to 25 mg when flags or toleration say so. Climb to 100 mg only after the meal clock and the attempt log are honest.

Ladder annotation dated 21 August 2026. Parent page: sildenafil letter. Factual corrections: [email protected].