Healthcare provider profile · identity verified

Daniel S. Wittkop, MD

Internal Medicine · SACRAMENTO, CA · NPI 1730267410

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
Hydrocodone-AcetaminophenHydrocodone/Acetaminophen335242
Albuterol Sulfate HfaAlbuterol Sulfate265236
Atorvastatin CalciumAtorvastatin Calcium237195
Amlodipine BesylateAmlodipine Besylate203154
PaxlovidNirmatrelvir/Ritonavir172172
Levothyroxine SodiumLevothyroxine Sodium163121
Losartan PotassiumLosartan Potassium159126
LisinoprilLisinopril137102
Fluticasone PropionateFluticasone Propionate12597
IbuprofenIbuprofen125117
GabapentinGabapentin10584
FurosemideFurosemide8967
OmeprazoleOmeprazole8573
Pantoprazole SodiumPantoprazole Sodium8567
FamotidineFamotidine7857
Trazodone HclTrazodone Hcl7560
HydrochlorothiazideHydrochlorothiazide7362
AlvescoCiclesonide7161
CephalexinCephalexin7070
Amoxicillin-Clavulanate PotassAmoxicillin/Potassium Clav6868
AtenololAtenolol6345
Hydralazine HclHydralazine Hcl6338
Potassium ChloridePotassium Chloride6345
Oxycodone-AcetaminophenOxycodone Hcl/Acetaminophen5641
Lisinopril-HydrochlorothiazideLisinopril/Hydrochlorothiazide5542
MeloxicamMeloxicam5343
Losartan-HydrochlorothiazideLosartan/Hydrochlorothiazide5135
Metformin Hcl ErMetformin Hcl5142
Metoprolol TartrateMetoprolol Tartrate4843
Rosuvastatin CalciumRosuvastatin Calcium4837
Metoprolol SuccinateMetoprolol Succinate4735
PrednisonePrednisone4747
Tramadol HclTramadol Hcl4737
LorazepamLorazepam4535
GlipizideGlipizide4333
Tamsulosin HclTamsulosin Hcl4331
Sertraline HclSertraline Hcl4232
Terazosin HclTerazosin Hcl3926
Alendronate SodiumAlendronate Sodium3731
BaclofenBaclofen3630
AlprazolamAlprazolam3529
Metformin HclMetformin Hcl3530
SimvastatinSimvastatin3430
PregabalinPregabalin3327
SpironolactoneSpironolactone3322
Acetaminophen-CodeineAcetaminophen With Codeine3219
Zolpidem TartrateZolpidem Tartrate3225
AmoxicillinAmoxicillin3130
OzempicSemaglutide3023
Triamcinolone AcetonideTriamcinolone Acetonide3026
Fluoxetine HclFluoxetine Hcl2926
Hydroxyzine HclHydroxyzine Hcl2825
Spiriva RespimatTiotropium Bromide2820
Montelukast SodiumMontelukast Sodium2722
Wixela InhubFluticasone Propion/Salmeterol2721
ClonazepamClonazepam2516
ClopidogrelClopidogrel Bisulfate2520
Donepezil HclDonepezil Hcl25suppressed
Doxycycline MonohydrateDoxycycline Monohydrate2524
CarvedilolCarvedilol2420
Duloxetine HclDuloxetine Hcl2423
JardianceEmpagliflozin2416
NaproxenNaproxen2321
Paxlovid (Eua)Nirmatrelvir/Ritonavir2323
Ondansetron OdtOndansetron2220
Oxycodone HclOxycodone Hcl2214
PradaxaDabigatran Etexilate Mesylate2218
Ciprofloxacin HclCiprofloxacin Hcl2121
NystatinNystatin2116
Tizanidine HclTizanidine Hcl2120
AllopurinolAllopurinol2019
Humulin NInsulin Nph Human Isophane2015
Ondansetron HclOndansetron Hcl2015
AzithromycinAzithromycin1918
Morphine Sulfate ErMorphine Sulfate1913
Clobetasol PropionateClobetasol Propionate1817
HydrocortisoneHydrocortisone1815
MirtazapineMirtazapine1813
TemazepamTemazepam1818
Adacel TdapDiph,pertuss(Acell),tet Vac/Pf1717
Pravastatin SodiumPravastatin Sodium1714
Propranolol HclPropranolol Hcl1711
Warfarin SodiumWarfarin Sodium1711
Bupropion XlBupropion Hcl1614
Citalopram HbrCitalopram Hydrobromide1614
KetoconazoleKetoconazole1612
Nitrofurantoin Mono-MacroNitrofurantoin Monohyd/M-Cryst1616
Sulfamethoxazole-TrimethoprimSulfamethoxazole/Trimethoprim1616
AcyclovirAcyclovir1513
FinasterideFinasteride1514
Ropinirole HclRopinirole Hcl15suppressed
Clonidine HclClonidine Hcl14suppressed
Oxybutynin Chloride ErOxybutynin Chloride14suppressed
ColchicineColchicine13suppressed
Divalproex Sodium ErDivalproex Sodium13suppressed
Triamterene-HydrochlorothiazidTriamterene/Hydrochlorothiazid1312
Trospium ChlorideTrospium Chloride13suppressed
Venlafaxine Hcl ErVenlafaxine Hcl1313
Diltiazem 24hr Er (Cd)Diltiazem Hcl12suppressed
Insulin Glargine-YfgnInsulin Glargine-Yfgn12suppressed
LidocaineLidocaine12suppressed
LovastatinLovastatin1211
Buspirone HclBuspirone Hcl11suppressed
LatanoprostLatanoprost11suppressed

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