Table 3. Practitioner Characteristics of Common Pharmacodynamically Interacting Medication Pairs Among New Users of QT-Prolonging Medications With Known TdP Risk in 2019a.
| Characteristic | Medication, No. (%) | ||||||
|---|---|---|---|---|---|---|---|
| Azithromycin | Ondansetron | Levofloxacin | Ciprofloxacin | Amiodarone | Escitalopram | Fluconazole | |
| New-use episodes, No. | 3168 | 2546 | 2203 | 1875 | 638 | 310 | 682 |
| First new episodes, No. | 3018 | 2463 | 2130 | 1816 | 634 | 310 | 665 |
| Concurrent use with another QT-prolonging medication with known TdP riskb | 516 (17.1) | 582 (23.6) | 463 (21.7) | 367 (20.2) | 104 (16.4) | 54 (17.4) | 174 (26.2) |
| Pharmacies | |||||||
| Different | 83 (16.1) | 64 (11.0) | 68 (14.7) | 48 (13.1) | 15 (14.4) | SC | 16 (9.2) |
| Same | 433 (83.9) | 518 (89.0) | 395 (85.3) | 319 (86.9) | 89 (85.6) | 51 (94.4) | 158 (90.8) |
| Commercial or retail | 363 (83.8) | 359 (69.3) | 298 (75.4) | 268 (84.0) | 67 (75.3) | 31 (60.8) | 125 (79.1) |
| Institutionalc | 69 (15.9) | 153 (29.5) | 93 (23.5) | 47 (14.7) | 20 (22.5) | 19 (37.3) | 30 (19.0) |
| Other | SC | SC | SC | SC | SC | SC | SC |
| Mail order | SC | SC | SC | SC | SC | SC | SC |
| Prescribers | |||||||
| Different | 338 (65.5) | 315 (54.1) | 292 (63.1) | 234 (63.8) | 64 (61.5) | 25 (46.3) | 96 (55.2) |
| Same | 178 (34.5) | 267 (45.9) | 171 (36.9) | 133 (36.2) | 40 (38.5) | 29 (53.7) | 78 (44.8) |
| General medicined | 121 (68.0) | 195 (73.0) | 130 (76.0) | 82 (61.7) | 30 (75.0) | 25 (86.2) | 51 (65.4) |
| Nephrology | 15 (8.4) | 11 (4.1) | 11 (6.4) | 16 (12.0) | SC | SC | SC |
| Othere | 26 (14.6) | 36 (13.5) | 17 (9.9) | 20 (15.0) | SC | SC | 13 (16.7) |
| Unknown | 16 (9.0) | 25 (9.4) | 13 (7.6) | 15 (11.3) | SC | SC | SC |
Abbreviations: SC, small cell size; TdP, torsades de pointes.
a
The table reports SC (<11) for data that may be identifiable, according to the Centers for Medicare & Medicaid Services’ data-use reporting requirements.
b
Denominators for pharmacy and prescriber data.
c
Pharmacy within long-term care facility.
d
Includes internal medicine, family medicine, and general practice.
e
Includes emergency medicine, cardiology, infectious diseases, hospitalist medicine, psychiatry, surgery, medical genetics, allergy, immunology, podiatry, physical medicine and rehabilitation, otolaryngology, dentistry, dermatology, radiology, legal medicine, neuromusculoskeletal medicine, nuclear medicine, optometry, and pathology.