Vanji Karthikeyan, MD
Nephrology · Detroit, MINPI 1003984550
Payments from drug & device makers
What this record shows
4 manufacturers reported payments, led by Calliditas Therapeutics US Inc. at 46.5% of the total. That places this record below the midpoint for nephrology clinicians in MI, where the typical reported total is $606.
Across 4 payments — averaging $62.48 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Calliditas Therapeutics US Inc.$116
- OPKO Pharmaceuticals, LLC$100
- Travere Therapeutics, Inc.$19
- Nxstage Medical, Inc.$14
Across 10 payments — averaging $7172.95 each. Payments tied to a research study. These frequently flow through the physician to a hospital or research institution rather than to the physician personally.
- Astellas Pharma Global Development$72K
What the payments were for
- Food & beverage$15060%
- Education$10040%
Most of this is food and beverage — typically meals provided during product presentations at a clinic or hospital. Nationally that is the single largest category of reported payments by count.
General payments by program year
Who reported the general payments
Companies are grouped under their corporate parent — a single manufacturer often files under several CMS reporting entities. Research and ownership payments are counted separately and are not in this table.
| Company | Payments | Total |
|---|---|---|
| Calliditas Therapeutics US Inc. | 1 | $116 |
| OPKO Pharmaceuticals, LLC | 1 | $100 |
| Travere Therapeutics, Inc. | 1 | $19 |
| Nxstage Medical, Inc. | 1 | $14 |
What the payments were tied to
Products named in the reported payments. Only payments of $100 or more are attributed here — the typical reported payment nationally is a meal worth about $16, and listing those product-by-product would be noise.
How this compares
$250 in reported general payments places this provider in the 30th percentile of 325 nephrology providers in Michigan.
Medicare billing
What this is not: this is the amount Original Medicare Part B allowed for services this provider billed in 2024. It is not their income. It excludes Medicare Advantage — now more than half of all Medicare enrollment — along with Medicaid and all commercial insurance, and it is gross practice revenue before staff, rent, supplies and malpractice premiums. CMS also suppresses any figure covering ten or fewer patients, so low-volume providers appear smaller than they are.
Most prescribed under Part D
| Drug | Claims | Cost to plans & patients |
|---|---|---|
| LokelmaSodium Zirconium Cyclosilicate | 11 | $8,227 |
| Sevelamer Carbonate | 16 | $3,951 |
| Calcium Acetate | 17 | $2,214 |
| Tacrolimus | 16 | $1,443 |
| Nifedipine ErNifedipine | 15 | $1,073 |
| Bumetanide | 13 | $659 |
| Losartan Potassium | 36 | $653 |
| Lisinopril | 29 | $337 |
| Prednisone | 25 | $187 |
| Metoprolol Succinate | 13 | $154 |
| Atorvastatin Calcium | 13 | $141 |
| Carvedilol | 21 | $118 |
| Calcitriol | 15 | $86 |
| Famotidine | 13 | $59 |
Paid to pharmacies, not to this prescriber.
Other nephrology in Detroit
- Anatole BesarabDetroit$102K
- Kausik UmanathDetroit$85K
- Aris UrbanesDetroit$14K
- Alexander YevzlinAnn Arbor$1.1M
- Muwaffaq SalamehBay City$164K
- Laura MarianiAnn Arbor$150K
- Crystal Gardner-MartinLivonia$140K
- Katherine KwonSaint Joseph$111K
- Richard CrossSaint Clair Shores$96K
- Joel TopfRoseville$79K
Where these figures come from
- Payments: CMS Open Payments, program years 2019–2025 (publication P06302026_06032026).
- Billing: Medicare Physician & Other Practitioners, data year 2024. Original Medicare Part B only.
- Identity: NPPES NPI Registry, July 2026.