Table 2.
Frequencies and percentages of respondents to potential DDIs*
| Drug –drug combinations | Shouldn’t be used together Contra indication) n(%) | May be used together with monitoring n(%) | No interactions n(%) | Not sure n(%) |
|---|---|---|---|---|
| Warfarin and cimetidine | 169 (59.7) | 81 (28.6) | 21(7.4) | 12(4.2) |
| Sildenafil and isosorbide mononitrate | 211(74.6) | 64(22.6) | 6(2.1) | 2(0.7) |
| Conjugated estrogens and raloxifen | 66(23.3) | 112(39.6) | 77(27.2) | 28(9.9) |
| Fexofenadine HCL and metoprolol | 38(13.4) | 84(29.7) | 124(43.8) | 37(13.1) |
| Theophylline and ciprofloxacin | 113(39.9) | 99(35) | 53(18.7) | 18(6.4) |
| Pimozide and ketoconazole | 92(32.5) | 127(44.9) | 21(7.4) | 43(15.2) |
| Methyldopa and phenobarbital | 127(44.9) | 80(28.3) | 50(17.7) | 26(9.2) |
| Phenytoin and cimetidine | 148(52.3) | 87(30.7) | 23(8.1) | 25(8.8) |
| Itraconazole and quinidine | 107(37.8) | 105(37.) | 28(9.9) | 42(14.9) |
| Amiodarone and simvastatin | 72(25.4) | 122(43.1) | 63(22.3) | 26(9.2) |
| Methotrexate and probenecid | 60(21.2) | 120(42.4) | 54(19.1) | 47(16.7) |
| Diphenhydramine and warfarin | 45(15.9) | 122(43.1) | 87(30.7) | 29(10.2) |
| Raloxifene and alendronate | 30(10.6) | 120(42.4) | 91(32.2) | 39(13.8) |
| Warfarin and diflunisal | 82(29.0) | 106(37.5) | 31(11.0) | 64(22.6) |
| Amiodarone and fluconazole | 46(16.3) | 96(33.9) | 74(26.1) | 67(23.7) |
| Theophylline and omeprazole | 64(22.6) | 77(27.2) | 97(34.3) | 45(15.9) |
| Sulfinpyrazone and warfarin | 110(38.9) | 89(31.4) | 26(9.2) | 58(20.5) |
| Meperidine and phenelzine | 125(44.2) | 54(19.1) | 39(13.8) | 65(23.0) |
| Fluconazole and phenytoin | 109(38.5) | 107(37.8) | 44(15.5) | 23(8.1) |
| Warfarin and nortriptyline | 74(26.1) | 146(51.6) | 32(11.3) | 31(11) |
| Amoxicillin and acetaminophen with codeine | 18(6.4) | 52(18.4) | 197(69.6) | 16(5.7) |
| Digoxin and clarithromycin | 94(33.2) | 113(39.9) | 54(19.1) | 22(7.8) |
| Alprazolam and itraconazole | 72(25.4) | 107(37.8) | 60(21.2) | 44(15.5) |
| Dopamine and phenytoin | 76(26.9) | 114(40.3) | 36(12.7) | 57(20.1) |
| Ciprofloxacin and tizanidine | 70(24.7) | 91(32.2) | 57(20.1) | 65(23.0) |
| Cyclosporine and rifampicin | 102(36.0) | 88(31.1) | 39(13.8) | 54(19.1) |
*
Bold numbers are the corrected answers.