Sildenafil 4- Tacrolimus

Drugs that might be affected by amprenavir include antiarrhythmics, anticonvulsants, azole antifungals, benzodiazepines, calcium channel blockers, cisapride, clarithromycin, cyclosporine, ergot alkaloids, fentanyl, HMG-CoA reductase inhibitors, indinavir, methadone, nelfinavir, oral contraceptives, pimozide, rifabutin, ritonavir, saquinavir, sildenafil, tacrolimus, trazodone, tricyclic antidepressants, warfarin, and zidovudine. 

Drugs that may be affected by fosamprenavir include the following Amiodarone, amitriptyline, benzodiazepines, calcium channel blockers, cisapride, contraceptives (oral), cyclosporine, ergot derivatives, HMG-CoA reductase inhibitors, imipramine, itraconazole, ketoconazole, lidocaine (systemic), methadone, pimozide, quinidine, rifabutin, sildenafil, tacrolimus, vardenafil, warfarin. 

Lopinavir/Ritonavir (Kaletra) [Anrirelroviral/Protease Inhibitor] Uses HIV Infxn Action Protease inhibitor Dose Adults. Tx naive 2 tab PO daily or 1 tab PO bid Tx experiencedpt 1 tab PO bid (T dose if w/ amprenavir, efavirenz, fosamprenavir, nelfinavir, nevirapine) Peds. 7-15 kg 12/3 mg/kg PO bid 15-40 kg 10/2.5 mg/kg PO bid >40 kg Adult dose w/ food Caution [C, /-] Numerous interactions Contra w/drugs dependent on CYP3A/CYP2D6 (Table VI-8) Disp Tab, soln SE Avoid disulfiram (soln has EtOH), metronidazole GI upset, asthenia, T cholesterol/triglycerides, pancreatitis protease metabolic synd Interactions T Effects Wl clarithromycin, erythromycin T effects OF amiodarone, amprenavir, azole andfungals, bepridil, cisapride, cyclosporine, CCBs, ergot alkaloids, flecainide, flurazepam, HMG-CoA reductase inhibitors, indinavir, lidocaine, meperidine, midazolam, pimozide, propafenone, propoxyphene, quinidine, rifabutin, saquinavir, sildenafil, tacrolimus, terfenadine, triazolam, zolpidem 1 effects Wl barbiturates, carbamazepine, dexamethasone, didanosine, efavirenz, nevirapine, phenytoin, rifabutin, rifampin, St. John s wort 1 effects OF OCPs, warfarin EMS Use andarrhythmics and benzodiazepines... 

Drugs that may affect nelfinavir include anticonvulsants, azithromycin, azole antifungals, efavirenz, delavirdine, HMG-CoA reductase inhibitors, indinavir, interleukins, nevirapine, rifabutin, rifampin, ritonavir, saquinavir, St. John s wort. Drugs that may be affected by nelfinavir include amiodarone, antiarrhythmics (amiodarone, quinidine), azithromycin, benzodiazepines, efavirenz, ergot alkaloids, delavirdine, didanosine, fentanyl, indinavir, lamivudine methadone, nonsedating antihistamines, oral contraceptives, phenytoin, pimozide, quinidine, rifabutin, saquinavir, sildenafil, sirolimus, tacrolimus, zidovudine. 

Itraconazole Alfentanil, alprazolam, astemizole, atorvastatin, buspirone, cisapride, cyclosporine, delavirdine, diazepam, digoxin, felodipine, indinavir, loratadine, lovastatin, midazolam, nisoldipine, phenytoin, quinidine, ritonavir, saquinavir, sildenafil, simvastatin, sirolimus, tacrolimus, triazolam, verapamil, warfarin... 

Christ B, Brockmeier D, Hauck EW, Friemann S. Interactions of sildenafil and tacrolimus in men with erectile dysfunction after kidney transplantation. Urology 2001 58(4) 589-93. 

Clinically important, potentially hazardous interactions with alfentanil, aminophylline, amisulpride, amoxicillin, ampicillin, anticonvulsants, astemizole, atorvastatin, benzodiazepines, bromocriptine, buprenorphine, bupropion, carbamazepine, cilostazol, ciprofloxacin, cisapride, clindamycin, colchicine, cyclosporine, dasatinib, digoxin, dihydroergotamine, diltiazem, disopyramide, enoxacin, eplerenone, ergotamine, eszopiclone, everolimus, fluconazole, fluoxetine, fluvastatin, gatifloxacin, HMG-CoA reductase inhibitors, imatinib, itraconazole, ketoconazole, lomefloxacin, lorazepam, lovastatin, methadone, methylprednisolone, methysergide, midazolam, mizolastine, moxifloxacin, nitrazepam, norfloxacin, ofloxacin, paroxetine, pimozide, pravastatin, quinolones, ranolazine, repaglinide, rupatadine, sertraline, sildenafil, simvastatin, sparfloxacin, sulpiride, tacrolimus, terfenadine, triazolam, troleandomycin, vardenafil, verapamil, vinblastine, warfarin, zaleplon, zolpidem, zuclopenthixol... 

Methylprednisolone Midazolam Nisoldipine Phenytoin Pimozide Quinidine Ritonavir Saquinavir Sildenafil Simvastatin SiroUmus Sulfonylureas (glyburide, others) Tacrolimus Triazolam Trimetrexate Verapamil Ritonavir... 

A4 Amiodarone, azole antifungals, cimetidine, clarithromycin, cyclosporine, erythromycin, fluoroquinolones, grapefruit juice, HIV protease inhibitors, metronidazole, quinine. SSRIs, tacrolimus Antiarrhythmics, antidepressants, azole antifungals, benzodiazepines, calcium channel blockers, cyclosporine, delavirdine, doxorubicin, efavirenz, erythromycin, estrogens, HIV protease inhibitors, nefazodone. paclitaxel, proton pump inhibitors, HMG-CoA reductase inhibitors, rifabutin, rifampin, sildenafil, SSRIs, tamoxifen, trazodone, vinca anticancer agents... 

Sildenafil does not appear to affect the pharmacokinetics of tacrolimus. The levels of sildenafil were higher in patients taking tacrolimus than in healthy subjects, but it is not clear whether this was due to tacrolimus alone. A marked blood pressure drop occurred when both drugs were given in one study. 

It would appear that sildenafil does not affect tacrolimus levels, however, given the reduction in blood pressure seen in one study, it may be prudent to initially prescribe sildenafil at the 25 mg dose, as the authors of this study advise, and increase it as required and tolerated. 

Christ B, Brockmeier D, Hauck EW, Kamali-Emst S. Investigation on interaction between tacrolimus and sildenafil in kidney-transplanted patients with erectile dysfunction. Int J Clin Pharmacol Ther (200A) 42, 149-56. 

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