Healthcare provider profile · identity verified

Samuel C Castles, MD

Family Practice · ANCHORAGE, AK · NPI 1033730015

Profile state: partd only Open Payments: 2025 Medicare Part D: 2024 Last identity check: 2026-08-10 Page data build: 2026-08-12

Verified facts

What the public records show

We did not find matching Open Payments records for this doctor in 2025.

These records do not establish that a payment influenced prescribing or medical care.

Payment overview · 2025

General Payments

We did not find matching Open Payments records for this doctor in the selected program year.

Separate record types

Research & Ownership

Research Payments (direct recipient): not present in the loaded data

Associated Research Funding (for example, named PI): not present in the loaded data

Ownership / Investment: not present in the loaded data

These categories are never added into the General Payments headline. Associated research funding must not be described as money the doctor personally received unless the source record supports that conclusion.

Analysis 1 · Payment-linked products

Products named in Open Payments records

No payment-linked product analysis is available because no matching General Payment records were found for the selected year.

Public prescribing for products named in payments

There is no explicit payment-product set available for a Part D comparison.

The presence of the same drug in both datasets does not show that a payment caused or influenced a prescription.

Analysis 2 · Same-company prescribing overlap

Drugs reported in other payments from the same company that also appear in Medicare Part D

This analysis is independent from products named on this doctor’s individual payment records. A row appears only when the exact Open Payments reporting entity paid this doctor, that same reporting entity reported the drug or biological on at least 10 loaded General Payment records involving at least 2 distinct recipient NPIs, and this doctor has the same non-generic brand in public Part D data. This does not mean the company owns or manufactures the drug.

There is no payer-company set available for this comparison.

These facts do not show that a payment was for the drug, that the company owns or manufactures the drug, or that a payment caused or influenced prescribing.

Public Medicare Part D data

Provider-and-drug rows loaded for 2024

BrandGenericClaimsBeneficiaries
Atorvastatin CalciumAtorvastatin Calcium15827
OmeprazoleOmeprazole12722
Amlodipine BesylateAmlodipine Besylate9019
Losartan PotassiumLosartan Potassium8821
LisinoprilLisinopril7219
Trazodone HclTrazodone Hcl67suppressed
Tamsulosin HclTamsulosin Hcl6413
GabapentinGabapentin62suppressed
Metoprolol SuccinateMetoprolol Succinate5611
Sertraline HclSertraline Hcl56suppressed
OzempicSemaglutide54suppressed
RisperidoneRisperidone53suppressed
Donepezil HclDonepezil Hcl47suppressed
Pantoprazole SodiumPantoprazole Sodium47suppressed
SynthroidLevothyroxine Sodium45suppressed
Fluticasone PropionateFluticasone Propionate40suppressed
Rosuvastatin CalciumRosuvastatin Calcium40suppressed
Levothyroxine SodiumLevothyroxine Sodium38suppressed
Quetiapine FumarateQuetiapine Fumarate36suppressed
Metformin HclMetformin Hcl35suppressed
SimvastatinSimvastatin30suppressed
Oxycodone HclOxycodone Hcl29suppressed
EliquisApixaban28suppressed
PregabalinPregabalin28suppressed
Duloxetine HclDuloxetine Hcl27suppressed
FinasterideFinasteride27suppressed
BaclofenBaclofen26suppressed
Phenytoin Sodium ExtendedPhenytoin Sodium Extended26suppressed
Fluoxetine HclFluoxetine Hcl25suppressed
CarvedilolCarvedilol24suppressed
Albuterol Sulfate HfaAlbuterol Sulfate22suppressed
ClopidogrelClopidogrel Bisulfate22suppressed
Metformin Hcl ErMetformin Hcl21suppressed
FamotidineFamotidine19suppressed
LidocaineLidocaine19suppressed
Divalproex Sodium ErDivalproex Sodium18suppressed
Ranolazine ErRanolazine17suppressed
EzetimibeEzetimibe16suppressed
LevetiracetamLevetiracetam16suppressed
AtenololAtenolol15suppressed
Carbamazepine ErCarbamazepine15suppressed
AllopurinolAllopurinol14suppressed
ClobazamClobazam14suppressed
TopiramateTopiramate14suppressed
Isosorbide Mononitrate ErIsosorbide Mononitrate13suppressed
Valproic AcidValproic Acid13suppressed
Bupropion XlBupropion Hcl12suppressed
FenofibrateFenofibrate Nanocrystallized12suppressed
HydrochlorothiazideHydrochlorothiazide12suppressed
Montelukast SodiumMontelukast Sodium12suppressed
OlanzapineOlanzapine12suppressed
Triamcinolone AcetonideTriamcinolone Acetonide12suppressed
AripiprazoleAripiprazole11suppressed
Propranolol HclPropranolol Hcl11suppressed
Tizanidine HclTizanidine Hcl11suppressed

Timeline

Payment and prescribing data by year

Open Payments and Medicare Part D may refer to different years. They are shown separately rather than aligned as if they describe the same period.

YearGeneral PaymentsMain payerExplicit productsCompany overlapsPart D coverage
2025
2024 Complete

Questions to ask

Questions you could discuss with your doctor

These are general questions generated from reviewed templates. They are not personalized medical advice.

Sources and limitations

How to read this page

Loaded source releases

DatasetYearPublicationSource
CMS Open Payments — General Payments 2025 2026-06-30 Original source
Medicare Part D Prescribers by Provider and Drug 2024 2026-05-06 Original source
NPPES Data Dissemination V2 current / reference data 2026-08-10 Original source

Methodology version: 2.1

Editorial template version: 2.4

Product contract version: 2.0

Schema version: 0.7.0

Page data build: 2026-08-12T23:34:59.370714+00:00

Publication policy: eligible for indexing after public-launch controls are enabled

Full methodology · Questions & answers · Report a possible error