Table 3.
Predictors of drug–drug interactions in users of PPI, according to the risk described on SPC and Drugdex
| SPC Patients at interaction risk∧n = 324 (%) | Adjusted* OR (95% CI) | Drugdex Patients at interaction risk∧n = 958 (%) | Adjusted* OR (95% CI) | |
|---|---|---|---|---|
| Age group | ||||
| 15–29 years | 15 (4.6) | 1.00 | 31 (3.2) | 1.00 |
| 30–44 years | 42 (13.0) | 0.89 (0.49, 1.60) | 75 (7.8) | 0.73 (0.48, 1.11) |
| 45–59 years | 85 (26.2) | 1.22 (0.70, 2.12) | 155 (16.2) | 0.94 (0.64, 1.39) |
| 60–74 years | 118 (36.4) | 1.51 (0.87, 2.62) | 351 (36.6) | 1.73 (1.19, 2.51) |
| 74 years | 64 (19.8) | 1.46 (0.81, 2.62) | 346 (36.1) | 2.89 (1.96, 4.16) |
| Sex | ||||
| Male | 164 (50.6) | 1.02 (0.82, 1.27) | 468 (48.9) | 1.03 (0.91, 1.17) |
| Female | 160 (49.4) | 1.00 | 490 (51.1) | 1.00 |
| Indication of use for PPI | ||||
| GERD | 103 (31.8) | 1.00 | 284 (29.6) | 1.00 |
| Gastroduodenal ulcer | 91 (28.1) | 1.40 (1.06, 1.87) | 250 (26.1) | 1.26 (1.06, 1.49) |
| Gastro-duodenitis | 44 (13.6) | 1.26 (0.88, 1.80) | 145 (15.1) | 1.35 (1.10, 1.65) |
| Other GI diseases | 47 (14.5) | 1.78 (1.25, 2.52) | 132 (13.8) | 1.49 (1.21, 1.83) |
| Gastroprotection | 6 (1.9) | 0.35 (0.15, 0.80) | 62 (6.5) | 1.14 (0.86, 1.50) |
| Not reported | 33 (10.2) | 2.33 (1.57, 3.48) | 85 (8.9) | 1.87 (1.46, 2.39) |
| Type of PPI | ||||
| Omeprazole | 149 (46.0) | 1.00 | 356 (37.2) | 1.00 |
| Pantoprazole | 1 (0.3) | 0.02 (0.01, 0.11) | 47 (4.9) | 0.36 (0.26, 0.48) |
| Rabeprazole | 12 (3.7) | 0.40 (0.22, 0.72) | 25 (2.6) | 0.45 (0.30, 0.68) |
| Lansoprazole | 45 (13.9) | 0.48 (0.34, 0.67) | 246 (25.7) | 1.20 (1.01, 1.41) |
| Esomeprazole | 32 (9.9) | 0.37 (0.25, 0.54) | 80 (8.4) | 0.51 (0.40, 0.65) |
| Combinations | 85 (26.2) | 1.40 (1.07, 1.83) | 204 (21.3) | 1.42 (1.19, 1.68) |
| Number of PPI prescriptions per month | ||||
| 0 | 199 (61.4) | 1.00 | 534 (55.7) | 1.00 |
| 1 | 81 (25.0) | 1.67 (1.28, 2.18) | 284 (29.7) | 1.70 (1.46, 1.97) |
| >1 | 44 (13.6) | 1.97 (1.41, 2.76) | 140 (14.6) | 1.85 (1.54, 2.23) |
| Number of other drug prescriptions per month | ||||
| 0 | 64 (19.8) | 1.00 | 113 (11.8) | 1.00 |
| 1–5 | 208 (64.2) | 1.45 (1.25, 1.70) | 641 (66.9) | 1.65 (1.34, 2.05) |
| >5 | 52 (16.0) | 1.36 (1.00, 1.85) | 204 (21.3) | 3.01 (2.33, 3.90) |
∧
Patients receiving at least one concomitant prescription of PPI and potentially interacting drugs, according to the Italian SPC of PPIs or Drugdex.
*
Adjusted for all variables included in the table.