T-01
Dapsone gel application-quantity guide
Label language first (a pea-sized amount, thin layer), fingertip-unit arithmetic second: grams per application, per day, per week, and how many days a 30, 60 or 90 gram pump or tube actually lasts at once-daily (7.5%) or twice-daily (5%) schedules.
Review-gated tool: this tool is excluded from search and AI citation. It is not medication, application, laboratory-monitoring, or treatment guidance and has no named clinician review.
Label language first (a pea-sized amount, thin layer), fingertip-unit arithmetic second: grams per application, per day, per week, and how many days a 30, 60 or 90 gram pump or tube actually lasts at once-daily (7.5%) or twice-daily (5%) schedules.
Both routes have established label regimens. Gel 7.5%: pea-sized amount in a thin layer to the entire face once daily, other affected areas as directed; reassess at 12 weeks. Gel 5%: pea-sized amount to affected areas twice daily; reassess at 12 weeks. Oral (specialist territory, shown as education only): dermatitis herpetiformis 50 to 300 mg daily titrated to minimum; leprosy 100 mg daily in combination.
Quantity plan
Select at least one body area to size the application.
Worked example
Worked example: a 12-week course on the 7.5% label schedule
The label says: pea-sized amount, thin layer, entire face, once daily. The FTU standard makes that measurable: face and neck take about 2.5 fingertip units. 2.5 FTU x 0.5 g per FTU = 1.25 g per application (the 0.5 g figure is the standard convention, labeled as such). Once daily means 1.25 g per day, 8.75 g per week. A 60 g pump at 1.25 g per day lasts floor(60 / 1.25) = 48 days; a 12-week (84-day) course needs two 60 g pumps or one 90 g pump plus a 30 g. The label's checkpoint: if there is no improvement after 12 weeks, treatment should be reassessed; the tool prints that reminder on every output card. Print or copy the card and take it to the prescriber and pharmacist; quantity planning is the tool's whole job, dose decisions are theirs.
Frequently asked questions
Why does the tool show FTUs when the label says pea-sized?
Because the label's language is the instruction and the FTU is the measurement. We show the label text first, then translate to fingertip units (face and neck about 2.5 FTU, about 1.25 g) so tube life is computable. The 0.5 g per FTU figure is a stated convention, not label text.
Which gel lasts longer per package?
At the same package size, the 7.5% once-daily schedule lasts twice as long as the 5% twice-daily schedule for the same treated area: a 60 g package runs about 48 days versus 24 at 2.5 FTU per application. It also delivers 25 to 40% less systemic dapsone.
Why is there no oral-dose calculator?
Deliberate. Oral dapsone is a monitored systemic drug with a CBC calendar and specialist titration; a consumer dosing calculator would be the exact route-blurring this site exists to prevent. The oral data appear as label education in the route explorer instead.
Where do the exposure numbers in the route explorer come from?
From the labels and their cited crossover study: AUC 415 ng.h/mL (5% gel, day 14) versus 52,641 ng.h/mL (single oral 100 mg), Cmax 13.0 ng/mL (7.5% steady state), and about 2,300 ng/mL chronic oral troughs from the cimetidine studies. Each bar links its claim id.
Tools: educational calculators and references only.