OpenBilldrug price receipt

NADAC week of 2026-10-14

TOPAMAX 25 MG TABLET

FDA nonproprietary name: topiramate

For 30 tablets

Pharmacies pay

$197.33 filed

30 × $6.57757 per EA

CMS NADAC · nadac-national-average-drug-acquisition-cost-20261014.csv · eff. 2026-09-23 · as of 2026-10-14 · retrieved 2026-10-17

Medicare Part D paid

$479.76 filed

30 × $15.99196 per EA, Part D average

Medicare's price is not your price.

Medicare Part D · DSD_PTD_RY26_P04_V10_DY24_BGM.csv · eff. 2024-01-01 to 2024-12-31 · as of 2026-06-25 · retrieved 2026-10-18


The spread

2.4× estimated

Medicare paid 2.4× what pharmacies pay.

Part D averages every strength and form sold under “Topamax” / “Topiramate” into one figure, so it is not specific to this NDC.

OpenBill calculation · DSD_PTD_RY26_P04_V10_DY24_BGM.csv + nadac-national-average-drug-acquisition-cost-20261014.csv · NADAC eff. 2026-09-23 (file of 2026-10-14, retrieved 2026-10-17) · Part D 2024-01-01 to 2024-12-31 (file of 2026-06-25, retrieved 2026-10-18)

Cost-plus estimate

$231.93 estimated

$197.33 + $29.60 (15%) + $5.00 fee per fill = $231.93

This is a model, not a price any pharmacy quoted. Shipping is not included. How it is worked out

OpenBill calculation · nadac-national-average-drug-acquisition-cost-20261014.csv · NADAC eff. 2026-09-23 (file of 2026-10-14, retrieved 2026-10-17)

Open the interactive card Change the quantity, type what you were charged, and see every record in full.

What it is

TOPAMAX 25 MG TABLET is how the CMS NADAC file names this product. The FDA NDC Directory lists it as topiramate, under the trade name “Topamax”.

FDA gives its dosage form as tablet, coated and its route as oral.

The labeler, the company named on the label, is Janssen Pharmaceuticals, Inc.

FDA lists no Established Pharmacologic Class for it.

The NADAC file of 2026-10-14 prices it under one NDC (National Drug Code), 50458-0639-65.

NADAC classes it as a brand-name drug (rate-setting class B), and does not mark it as sold over the counter.

What pharmacies pay

Pharmacies pay $197.33 for 30 tablets (30 × $6.57757 per EA, rounded to the cent), by the CMS NADAC file of 2026-10-14; that price took effect on 2026-09-23. That is what pharmacies pay their suppliers, not what they charge you.

NADAC’s explanation code for it: 1, calculated from the most recently completed pharmacy survey.

NADAC also lists, on the row of one brand NDC, what pharmacies pay for the generic equivalent, a different product: $0.02684 per EA filed.

CMS NADAC · nadac-national-average-drug-acquisition-cost-20261014.csv · eff. 2026-09-23 · as of 2026-10-14 · retrieved 2026-10-17

The NDC

Other strengths, forms and brands

26 other products in the NADAC file share the FDA nonproprietary name topiramate with TOPAMAX 25 MG TABLET. The 23 below share a strength or dosage form with it first; search OpenBill for the rest.

ProductPharmacies pay per unitMedicare per unit
EPRONTIA 25 MG/ML SOLUTION
brand · solution
$1.58252 to $2.7158 per ML filed
eff. 2026-01-01 to 2026-09-23
$1.88561 per ML filed
Part D 2024 average
TOPAMAX 25 MG SPRINKLE CAP
brand · capsule, coated pellets
$7.53998 per EA filed
eff. 2026-09-23
$15.99196 per EA filed
Part D 2024 average
TOPAMAX 25 MG TABLET this page
brand · tablet, coated
$6.57757 per EA filed
eff. 2026-09-23
$15.99196 per EA filed
Part D 2024 average
TOPAMAX 50 MG TABLET
brand · tablet, coated
$13.13389 per EA filed
eff. 2026-09-23
$15.99196 per EA filed
Part D 2024 average
TOPAMAX 100 MG TABLET
brand · tablet, coated
$17.91087 per EA filed
eff. 2026-09-23
$15.99196 per EA filed
Part D 2024 average
TOPAMAX 200 MG TABLET
brand · tablet, coated
$21.07055 per EA filed
eff. 2026-09-23
$15.99196 per EA filed
Part D 2024 average
TOPIRAMATE 15 MG SPRINKLE CAP
generic · capsule / capsule, coated pellets
$0.22941 per EA filed
eff. 2026-09-23
$0.12224 per EA filed
Part D 2024 average
TOPIRAMATE 25 MG SPRINKLE CAP
generic · capsule / capsule, coated pellets
$0.24588 per EA filed
eff. 2026-09-23
$0.12224 per EA filed
Part D 2024 average
TOPIRAMATE 25 MG TABLET
generic · tablet, film coated / tablet
$0.02684 per EA filed
eff. 2026-09-23
$0.12224 per EA filed
Part D 2024 average
TOPIRAMATE 25 MG/ML SOLUTION
generic · solution
$1.08239 to $2.08667 per ML filed
eff. 2026-09-23
We don’t know yet
TOPIRAMATE 50 MG SPRINKLE CAP
generic · capsule, coated pellets / capsule
$4.32398 per EA filed
eff. 2026-09-23
$0.12224 per EA filed
Part D 2024 average
TOPIRAMATE 50 MG TABLET
generic · tablet, film coated / tablet
$0.03705 per EA filed
eff. 2026-09-23
$0.12224 per EA filed
Part D 2024 average
TOPIRAMATE 100 MG TABLET
generic · tablet, film coated / tablet
$0.05669 per EA filed
eff. 2026-09-23
$0.12224 per EA filed
Part D 2024 average
TOPIRAMATE 200 MG TABLET
generic · tablet, film coated / tablet
$0.11016 per EA filed
eff. 2026-09-23
$0.12224 per EA filed
Part D 2024 average
TOPIRAMATE ER 25 MG CAPSULE
generic · capsule, extended release
$4.13989 per EA filed
eff. 2026-09-23
$13.19463 per EA filed
Part D 2024 average
TOPIRAMATE ER 25 MG SPRINKL CAP
generic · capsule, extended release
$2.25428 per EA filed
eff. 2026-09-23
$13.19463 per EA filed
Part D 2024 average
TOPIRAMATE ER 50 MG CAPSULE
generic · capsule, extended release
$6.17393 per EA filed
eff. 2026-09-23
$13.19463 per EA filed
Part D 2024 average
TOPIRAMATE ER 50 MG SPRINKL CAP
generic · capsule, extended release
$3.14622 per EA filed
eff. 2026-09-23
$13.19463 per EA filed
Part D 2024 average
TOPIRAMATE ER 100 MG CAPSULE
generic · capsule, extended release
$10.67522 per EA filed
eff. 2026-09-23
$13.19463 per EA filed
Part D 2024 average
TOPIRAMATE ER 100 MG SPRINK CAP
generic · capsule, extended release
$5.49212 per EA filed
eff. 2026-09-23
$13.19463 per EA filed
Part D 2024 average
TOPIRAMATE ER 150 MG SPRINK CAP
generic · capsule, extended release
$7.35688 per EA filed
eff. 2026-09-23
$13.19463 per EA filed
Part D 2024 average
TOPIRAMATE ER 200 MG CAPSULE
generic · capsule, extended release
$20.37363 per EA filed
eff. 2026-09-23
$13.19463 per EA filed
Part D 2024 average
TOPIRAMATE ER 200 MG SPRINK CAP
generic · capsule, extended release
$9.54204 per EA filed
eff. 2026-09-23
$13.19463 per EA filed
Part D 2024 average
TROKENDI XR 25 MG CAPSULE
brand · capsule, extended release
$13.29949 per EA filed
eff. 2026-07-01
$31.9352 per EA filed
Part D 2024 average

Part D is one average per brand and generic name, over every strength and form.

CMS NADAC · nadac-national-average-drug-acquisition-cost-20261014.csv · eff. 2026-01-01, 2026-07-01, 2026-09-23 · as of 2026-10-14 · retrieved 2026-10-17

Medicare Part D · DSD_PTD_RY26_P04_V10_DY24_BGM.csv · eff. 2024-01-01 to 2024-12-31 · as of 2026-06-25 · retrieved 2026-10-18

What Medicare paid

Medicare Part D paid $479.76 for 30 tablets, at an average of $15.99196 per EA in 2024 (2024-01-01 to 2024-12-31) for “Topamax” and “Topiramate”, every strength and form sold under that name together (Medicare Part D Spending by Drug, file of 2026-06-25).

That average covers 21,528 Part D claims (fills, including refills) for 2024-01-01 to 2024-12-31, across every maker, strength and form under the name.

Medicare's price is not your price.

What to ask at the counter

None of these figures is your price: what you pay depends on your pharmacy, your insurance, coupons and discounts.

Questions

Why is the comparison with Medicare for TOPAMAX 25 MG TABLET labelled estimated?
Beyond what the card shows, the records give these reasons: The Part D figure covers 2024-01-01 to 2024-12-31; the NADAC price is from the file of 2026-10-14. Part D spending basis, as the Part D record states it: Part D 2024 average spend per dosage unit for Topamax / Topiramate: all makers, strengths, forms and routes combined, claim-weighted; gross cost incl. dispensing fees and patient pay, before rebates. Unit taken as NADAC's EA. Joined on brand name.