Skip to main content

Table 3 Potentially serious drug-drug interactions in 1995 and 2010

From: The rising tide of polypharmacy and drug-drug interactions: population database analysis 1995–2010

  1995 2010 2010  
No. (%) of patients No. (%) of patients Age-sex standardised % of patients* Age-sex standardised relative risk 2010 vs. 1995 (95% CI)
n = 301,019 n = 311,881 n = 311,881
All patients 17,448 (5.8) 40,689 (13.0) 12.1 2.08 (2.04–2.12)
No. of interactions     
0 283,571 (94.2) 271,192 (86.9) 87.9 0.91 (0.91–0.91)
1 13,051 (4.3) 23,907 (7.7) 7.1 2.41 (2.35–2.47)
2 3,151 (1.0) 9,324 (3.0) 2.8 5.54 (5.25–5.85)
3 814 (0.3) 3,776 (1.2) 1.1 7.03 (6.39–7.74)
4+ 432 (0.1) 3,682 (1.2) 1.1 13.8 (12.1–15.7)
Any interaction involving drugs from BNF chapter     
1 (gastrointestinal) 197 (0.07) 1,452 (0.47) 0.42 6.30 (5.44–7.31)
2 (cardiovascular) 14,236 (4.7) 34,124 (10.9) 9.9 2.09 (2.05–2.13)
3 (respiratory) 863 (0.30) 863 (0.28) 0.26 0.84 (0.77–0.93)
4 (central nervous system) 3,489 (1.2) 11,465 (3.7) 3.4 2.93 (2.81–3.04)
5 (infections) 1,062 (0.37) 1,526 (0.49) 0.45 1.22 (1.13–1.32)
6 (endocrine) 688 (0.23) 1,588 (0.51) 0.47 2.00 (1.83–2.19)
7 (O&G, and urinary tract) 257 (0.09) 2,516 (0.81) 0.68 7.66 (6.75–8.69)
8 (malignancy, immunosuppression) 125 (0.04) 207 (0.07) 0.06 1.44 (1.15–1.79)
9 (nutrition and blood) 252 (0.09) 62 (0.02) 0.02 0.22 (0.16–0.29)
10 (musculoskeletal) 2,565 (0.87) 4,717 (1.5) 1.4 1.64 (1.56–1.72)
11 (eye) 21 (0.01) 9 (0.003) 0.003 0.38 (0.17–0.82)
12 (ear, nose, and throat) 0 0 0
13 (skin) 0 0 0
  1. *2010 data directly age-sex standardised to 1995 population structure.