DR. DEREK MICHAEL PHELPS OD
Prescription History 1316508708
Optometrist in Tempe, AZ
What does Dr. Phelps prescribe?
In 2024, Dr. Phelps wrote 588 Medicare prescriptions for 13 medications. The most prescribed was Prednisolone Acetate, with 137 prescriptions for 74 patients.
Medicare Part D only. These are prescriptions filled by people with Medicare drug coverage in 2024, from the CMS data released in 2026, the most recent year available. CMS does not publish medications with fewer than 11 prescriptions, so this is not a full list of what Dr. Phelps prescribes.
Medications 13 medications
Prescriptions filled under Medicare Part D in 2024. Select a medication to see what it is used for and how it compares with other Arizona prescribers.
What it is used for
This medication is used to treat certain eye conditions due to inflammation or injury.
Compared with Arizona prescribers
Dr. Phelps wrote 137 prescriptions for Prednisolone Acetate, about as often as the typical Arizona prescriber of it (147). Medicare paid $28.70 per fill, versus $38.96 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is used to treat certain eye conditions due to inflammation or injury.
Compared with Arizona prescribers
Dr. Phelps wrote 72 prescriptions for Fluorometholone, about 1.6 times as often as the typical Arizona prescriber of it (44). Medicare paid $68.52 per fill, versus $73.79 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Valacyclovir is used to treat infections caused by certain types of viruses.
Compared with Arizona prescribers
Dr. Phelps wrote 61 prescriptions for Valacyclovir, about 2.7 times as often as the typical Arizona prescriber of it (22). Medicare paid $51.26 per fill, versus $37.77 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This product contains two drugs used to treat high pressure inside the eye due to glaucoma (open angle-type) or other eye diseases (such as ocular hypertension).
Compared with Arizona prescribers
Dr. Phelps wrote 47 prescriptions for Dorzolamide-Timolol, about half as often as the typical Arizona prescriber of it (92). Medicare paid $21.49 per fill, versus $17.84 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Latanoprost is used to treat high pressure inside the eye due to glaucoma (open angle type) or other eye diseases (such as ocular hypertension).
Compared with Arizona prescribers
Dr. Phelps wrote 44 prescriptions for Latanoprost, about 27% as often as the typical Arizona prescriber of it (164). Medicare paid $20.31 per fill, versus $12.05 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is used to treat high pressure inside the eye due to glaucoma (open angle-type) or other eye diseases (such as ocular hypertension).
Compared with Arizona prescribers
Dr. Phelps wrote 42 prescriptions for Timolol Maleate, about half as often as the typical Arizona prescriber of it (99). Medicare paid $12.16 per fill, versus $11.63 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Cyclosporine eye drops are used to treat a certain type of dry eyes.
Compared with Arizona prescribers
Dr. Phelps wrote 37 prescriptions for Restasis, about 87% as often as the typical Arizona prescriber of it (43). Medicare paid $710.93 per fill, versus $1,039.87 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is used to treat certain eye infections (such as conjunctivitis).
Compared with Arizona prescribers
Dr. Phelps wrote 33 prescriptions for Erythromycin, about 72% as often as the typical Arizona prescriber of it (46). Medicare paid $14.57 per fill, versus $13.77 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is used to treat bacterial infections (such as blepharitis, conjunctivitis) of the eye.
Compared with Arizona prescribers
Dr. Phelps wrote 31 prescriptions for Polymyxin B Sul-Trimethoprim, about 1.4 times as often as the typical Arizona prescriber of it (22). Medicare paid $6.83 per fill, versus $8.42 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is a quinolone antibiotic used for eye infections.
Compared with Arizona prescribers
Dr. Phelps wrote 27 prescriptions for Moxifloxacin, about 34% as often as the typical Arizona prescriber of it (80). Medicare paid $12.42 per fill, versus $24.59 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is used to treat a wide variety of bacterial infections, including those that cause acne.
Compared with Arizona prescribers
Dr. Phelps wrote 24 prescriptions for Doxycycline Hyclate, about 75% as often as the typical Arizona prescriber of it (32). Medicare paid $56.94 per fill, versus $13.36 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
Acyclovir is used to treat infections caused by certain types of viruses.
Compared with Arizona prescribers
Dr. Phelps wrote 17 prescriptions for Acyclovir, about 65% as often as the typical Arizona prescriber of it (26). Medicare paid $23.47 per fill, versus $14.13 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
What it is used for
This medication is used to temporarily relieve itching eyes caused by seasonal allergies.
Compared with Arizona prescribers
Dr. Phelps wrote 16 prescriptions for Ketorolac Tromethamine, about 18% as often as the typical Arizona prescriber of it (87). Medicare paid $14.05 per fill, versus $23.58 statewide.
Volume reflects how many Medicare patients a practice sees as well as prescribing habits. It is not a measure of quality.
Questions about Dr. Phelps’s prescriptions
What does Dr. Phelps prescribe most?
In 2024 Medicare Part D data, Dr. Phelps's most prescribed medications were Prednisolone Acetate (137), Fluorometholone (72) and Valacyclovir (61).
How does Dr. Phelps's prescribing compare with other Arizona prescribers?
Of the 13 medications with a state comparison, Dr. Phelps prescribes 3 more often than the typical Arizona prescriber, 2 about as often and 8 less often. Volume reflects practice size as well as prescribing habits.
Does this list show every medication Dr. Phelps prescribes?
No. It covers prescriptions filled by people with Medicare Part D drug coverage in 2024, and CMS leaves out any medication with fewer than 11 prescriptions.
About this data
This page shows one provider’s slice of public Medicare files. NPI Profile does not receive prescriptions or patient records.
| Source | What it provides here | Data year |
|---|---|---|
| CMS Medicare Part D Prescribers by Provider and Drug | Each medication, prescriptions, patients, 30-day fills, days of medication and cost. State comparisons average the Arizona prescribers of the same medication and form, where at least five wrote it. | 2024 (released 2026, the most recent available) |
| CMS Medicare Part D Drug Spending Dashboard | What each medication is used for. | 2024 |
- Only prescriptions filled by people with Medicare Part D drug coverage are counted. Private insurance, Medicaid and cash purchases are not.
- CMS leaves out medications with fewer than 11 prescriptions and hides patient counts under 11.
- Cost per fill is what the plan and the patient paid the pharmacy together, not what you pay at the counter.
- Medication descriptions are summaries from CMS. They are not medical advice; ask a health care professional about any medication.
