Healthcare provider profile · identity verified

Dennis J. Park, DO

Internal Medicine · OAKBROOK TERRACE, IL · NPI 1639220445

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

Brand	Generic	Claims	Beneficiaries
Levothyroxine Sodium	Levothyroxine Sodium	361	53
Atorvastatin Calcium	Atorvastatin Calcium	270	55
Amlodipine Besylate	Amlodipine Besylate	248	43
Montelukast Sodium	Montelukast Sodium	228	49
Gabapentin	Gabapentin	217	45
Sertraline Hcl	Sertraline Hcl	201	27
Metoprolol Succinate	Metoprolol Succinate	190	24
Eliquis	Apixaban	182	30
Furosemide	Furosemide	161	36
Hydrocodone-Acetaminophen	Hydrocodone/Acetaminophen	160	44
Omeprazole	Omeprazole	149	30
Pantoprazole Sodium	Pantoprazole Sodium	139	27
Donepezil Hcl	Donepezil Hcl	137	19
Losartan Potassium	Losartan Potassium	133	23
Simvastatin	Simvastatin	128	18
Escitalopram Oxalate	Escitalopram Oxalate	127	22
Metoprolol Tartrate	Metoprolol Tartrate	123	21
Mirtazapine	Mirtazapine	113	15
Potassium Chloride	Potassium Chloride	113	20
Memantine Hcl	Memantine Hcl	112	13
Metformin Hcl	Metformin Hcl	108	23
Lisinopril	Lisinopril	93	31
Tamsulosin Hcl	Tamsulosin Hcl	85	13
Famotidine	Famotidine	81	19
Clopidogrel	Clopidogrel Bisulfate	73	14
Alprazolam	Alprazolam	72	27
Warfarin Sodium	Warfarin Sodium	67	12
Duloxetine Hcl	Duloxetine Hcl	63	12
Lorazepam	Lorazepam	60	19
Oxybutynin Chloride Er	Oxybutynin Chloride	60	suppressed
Diclofenac Sodium	Diclofenac Sodium	57	17
Glipizide Er	Glipizide	54	suppressed
Oxybutynin Chloride	Oxybutynin Chloride	54	suppressed
Breo Ellipta	Fluticasone/Vilanterol	52	suppressed
Tramadol Hcl	Tramadol Hcl	52	25
Trazodone Hcl	Trazodone Hcl	52	12
Triamcinolone Acetonide	Triamcinolone Acetonide	51	20
Benazepril Hcl	Benazepril Hcl	50	suppressed
Januvia	Sitagliptin Phosphate	49	suppressed
Loperamide	Loperamide Hcl	48	suppressed
Baclofen	Baclofen	47	11
Myrbetriq	Mirabegron	47	suppressed
Amiodarone Hcl	Amiodarone Hcl	43	suppressed
Sotalol	Sotalol Hcl	43	suppressed
Clonazepam	Clonazepam	39	suppressed
Pregabalin	Pregabalin	39	13
Quetiapine Fumarate	Quetiapine Fumarate	39	suppressed
Folic Acid	Folic Acid	37	suppressed
Albuterol Sulfate Hfa	Albuterol Sulfate	36	19
Rosuvastatin Calcium	Rosuvastatin Calcium	35	11
Pravastatin Sodium	Pravastatin Sodium	33	suppressed
Midodrine Hcl	Midodrine Hcl	32	suppressed
Acetaminophen-Codeine	Acetaminophen With Codeine	31	15
Spironolactone	Spironolactone	31	suppressed
Gemfibrozil	Gemfibrozil	30	suppressed
Doxepin Hcl	Doxepin Hcl	29	suppressed
Meloxicam	Meloxicam	29	suppressed
Alendronate Sodium	Alendronate Sodium	28	suppressed
Carbidopa-Levodopa	Carbidopa/Levodopa	28	suppressed
Nystatin	Nystatin	28	17
Ropinirole Hcl	Ropinirole Hcl	27	suppressed
Torsemide	Torsemide	27	suppressed
Lamotrigine	Lamotrigine	26	suppressed
Levetiracetam	Levetiracetam	26	suppressed
Phenobarbital	Phenobarbital	26	suppressed
Nystop	Nystatin	25	13
Azithromycin	Azithromycin	24	19
Enalapril Maleate	Enalapril Maleate	24	suppressed
Methenamine Hippurate	Methenamine Hippurate	24	suppressed
Allopurinol	Allopurinol	23	suppressed
Bumetanide	Bumetanide	23	suppressed
Creon	Lipase/Protease/Amylase	23	suppressed
Lactulose	Lactulose	23	suppressed
Xarelto	Rivaroxaban	23	suppressed
Latanoprost	Latanoprost	22	suppressed
Linzess	Linaclotide	22	suppressed
Losartan-Hydrochlorothiazide	Losartan/Hydrochlorothiazide	22	suppressed
Paroxetine Hcl	Paroxetine Hcl	22	suppressed
Buspirone Hcl	Buspirone Hcl	21	suppressed
Cyclobenzaprine Hcl	Cyclobenzaprine Hcl	21	suppressed
Nifedipine Er	Nifedipine	21	suppressed
Atenolol	Atenolol	20	suppressed
Esomeprazole Magnesium	Esomeprazole Magnesium	20	suppressed
Olanzapine	Olanzapine	20	suppressed
Sulfamethoxazole-Trimethoprim	Sulfamethoxazole/Trimethoprim	20	18
Fluoxetine Hcl	Fluoxetine Hcl	19	suppressed
Tizanidine Hcl	Tizanidine Hcl	19	suppressed
Citalopram Hbr	Citalopram Hydrobromide	18	suppressed
Digoxin	Digoxin	18	suppressed
Humalog Kwikpen U-100	Insulin Lispro	18	suppressed
Oxycodone-Acetaminophen	Oxycodone Hcl/Acetaminophen	18	suppressed
Trimethoprim	Trimethoprim	18	suppressed
Hydrochlorothiazide	Hydrochlorothiazide	17	suppressed
Methocarbamol	Methocarbamol	17	suppressed
Nitrofurantoin Mono-Macro	Nitrofurantoin Monohyd/M-Cryst	17	13
Triamterene-Hydrochlorothiazid	Triamterene/Hydrochlorothiazid	17	suppressed
Venlafaxine Hcl Er	Venlafaxine Hcl	17	suppressed
Basaglar Kwikpen U-100	Insulin Glargine,hum.Rec.Anlog	16	suppressed
Lantus Solostar	Insulin Glargine,hum.Rec.Anlog	16	suppressed
Modafinil	Modafinil	16	suppressed
Ibuprofen	Ibuprofen	15	suppressed
Letrozole	Letrozole	15	suppressed
Acyclovir	Acyclovir	14	suppressed
Amoxicillin-Clavulanate Potass	Amoxicillin/Potassium Clav	13	suppressed
Clonidine Hcl	Clonidine Hcl	13	suppressed
Ketoconazole	Ketoconazole	13	suppressed
Metformin Hcl Er	Metformin Hcl	13	suppressed
Solifenacin Succinate	Solifenacin Succinate	13	suppressed
Tolterodine Tartrate Er	Tolterodine Tartrate	13	suppressed
Hydroxychloroquine Sulfate	Hydroxychloroquine Sulfate	12	suppressed
Irbesartan	Irbesartan	12	suppressed
Propranolol Hcl	Propranolol Hcl	12	suppressed
Diazepam	Diazepam	11	suppressed
Levocetirizine Dihydrochloride	Levocetirizine Dihydrochloride	11	suppressed
Valsartan	Valsartan	11	suppressed
Vitamin D2	Ergocalciferol (Vitamin D2)	11	suppressed

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.

Year	General Payments	Main payer	Explicit products	Company overlaps	Part D coverage
2025	—	—	—	—	—
2024	—	—	—	—	Complete

Questions to ask

Questions you could discuss with your doctor

Are there reasonable alternatives I should understand when we discuss treatment options?
How should I interpret the industry-payment records shown here in the context of my care?

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

Sources and limitations

How to read this page

Payment and Medicare prescribing data can cover different years; every comparison shows both years explicitly.
Part D does not represent a doctor’s entire practice; it excludes many patients and is subject to CMS public-release thresholds.
Company–drug relationships must have an auditable source, a precise relationship type, and a valid evidence period. Unresolved mappings are not published.
Generic drug claims are not attributed to a specific manufacturer without manufacturer-level evidence.
When a source extract is incomplete, missing rows are never treated as proof of no payments or no prescriptions.

Loaded source releases

Dataset	Year	Publication	Source
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