Table 3.

Characteristics of potential drug–drug interactions

Drugs involved		Severity of interaction (only commonest drugs listed)				Total
		Contra-indications	Potential major interaction	Potential moderate interaction	Potential minor interaction
Aspirin	n (%)	0 (0%)	34 (23%)	236 (39.7%)	11 (16.4%)	281 (34.4%)
Lisinopril	n (%)	0 (0%)	6 (4.1%)	99 (16.6%)	9 (13.4%)	114 (14.0%)
Clopidogrel	n (%)	0 (0%)	2 (1.4%)	80 (13.4%)	1 (1.5%)	83 (10.2%)
Enalapril	n (%)	0 (0%)	1 (.7%)	62 (10.4%)	0 (0%)	63 (7.7%)
Atenolol	n (%)	0 (0%)	2 (1.4%)	60 (10.1%)	0 (0%)	62 (7.6%)
Bendroflumethiazide	n (%)	0 (0%)	53 (35.8%)	8 (1.3%)	0 (0%)	61 (7.5%)
Glipizide	n (%)	3 (50%)	8 (5.4%)	32 (5.4%)	18 (26.9%)	61 (7.5%)
Diclofenac	n (%)	0 (0%)	2 (1.4%)	58 (9.7%)	0 (0%)	60 (7.4%)
Metformin	n (%)	0 (0%)	5 (3.4%)	38 (6.4%)	13 (19.4%)	56 (6.9%)
Nifedipine	n (%)	0 (0%)	4 (2.7%)	46 (7.7%)	1 (1.5%)	51 (6.3%)
Type of Interaction(only commonest interactions listed)
Decreased efficacy	n (%)	2 (33.3%)	25 (16.9%)	291 (48.9%)	38 (56.7%)	356 (43.6%)
Enhanced effects	n (%)	2 (33.3%)	18 (12.2%)	156 (26.2%)	18 (26.9%)	194 (23.8%)
Hypoglycaemia	n (%)	0	11 (7.4%)	82 (13.8%)	1 (1.5%)	94 (11.5%)
Hypotension	n (%)	0	4 (2.7%)	70 (11.8%)	0 (.0%)	74 (9.1%)
Hyerglycemia	n (%)	0	11 (7.4%)	39 (6.6%)	0 (.0%)	50 (6.1%)
Rhabdomyolysis	n (%)	1 (16.7%)	33 (22.4%)	1 (.2%)	0 (.0%)	35 (4.3%)
GI hemorrhage	n (%)	0	0 (.0%)	25 (4.2%)	9 (13.4%)	34 (4.2%)
Bleeding (other)	n (%)	0	62 (41.9%)	28 (4.7%)	1 (1.5%)	91 (11.2%)
Thrombosis	n (%)	0	22 (14.8%)	2 (3.3%)	0 (.0%)	24 (2.9%)
Hyperkalemia	n (%)	0	6 (4.1%)	10 (1.7%)	0 (.0%)	16 (2.0%)
Lactic acidosis	n (%)	0	0 (.0%)	16 (2.7%)	0 (.0%)	16 (2.0%)
Total	n (%)	6 (100%)	148 (100%)	595 (100%)	67 (100%)	814 (100%)

Only the commonest drugs and interactions are listed

GI gastro-intestinal