enofovir-associated adverse reactions.
Teriflunomide: Concurrent use of teriflunomide, an inhibitor of the hepatic uptake organic anion transporting polypeptide OATP1B1, with some HMG-CoA reductase inhibitors (Statins), including atorvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin, or simvastatin may increase the AUC of the statin. Administration of cyclosporine, another OATP1B1 inhibitor, increased the plasma AUC of pravastatin 9.9-fold. Additive hepatotoxicity may occur. Caution should also be exercised when using combination dosage forms, such as amlodipine; atorvastatin, ezetimibe; simvastatin, lovastatin; niacin, niacin; simvastatin, and simvastatin; sitagliptin. Monitor patients for signs of myopathy or hepatotoxicity.
Tesamorelin: Use caution when coadministering tesamorelin with simvastatin as their concurrent use may alter simvastatin plasma concentrations. In a pharmacokinetic study, multiple 2 mg doses of tesamorelin administered with simvastatin resulted in an 8% decrease in simvastatin AUC and a 5% increase in simvastatin Cmax. The clinical impact of these pharmacokinetic changes are unknown; however, patients should be monitored for decreased simvastatin efficacy. Further, since simvastatin is a substrate for CYP3A4, it may be theorized that tesamorelin has little impact on CYP3A activity.
Ticagrelor: Avoid simvastatin doses > 40 mg/day PO when used concomitantly with ticagrelor as concomitant use will result in higher serum concentrations of simvastatin. Simvastatin is metabolized by CYP3A4 and ticagrelor is an inhibitor of CYP3A4.
Tigecycline: Coadministration of P-glycoprotein (P-gp) inhibitors, such as simvastatin, may increase tigecycline serum concentrations. Based on an in vitro study, tigecycline is a P-gp substrate; however, the potential contribution of P-gp-mediated transport to the in vivo disposition of tigecycline is not known.
Tipranavir: The coadministration of anti-retroviral protease inhibitors with simvastatin is contraindicated. Taking these drugs together may significantly increase the serum concentration of simvastatin; thereby increasing the risk of myopathy and rhabdomyolysis. One report has demonstrated that ritonavir plus saquinavir therapy markedly increases the AUC for simvastatin by 3059%. Simvastatin is a substrate for CYP3A4 and the drug transporter organic anion transporting polypeptide (OATP1B1); protease inhibitors are CYP3A4 and OATP inhibitors.
Tocilizumab: In vitro, tocilizumab has the potential to affect expression of multiple CYP enzymes, including CYP3A4. A 57% decrease in simvastatin exposure was noted 1 week after a single tocilizumab dose; simvastatin is a CYP3A4 substrate. Utilize caution when using tocilizumab in combination with CYP3A4 substrate drugs where a decrease in effectiveness is undesirable.
Topotecan: Avoid the concomitant use of simvastatin, a P-glycoprotein (P-gp) inhibitor, with oral topotecan, a P-gp substrate; P-gp inhibitors have less of an effect on intravenous topotecan and these may be coadministered with caution. If coadministration of simvastatin and oral topotecan is necessary, carefully monitor for increased toxicity of topotecan, including severe myelosuppression and diarrhea; this also applies to combination products containing simvastatin, such as ezetimibe; simvastatin, niacin; simvastatin, and simvastatin; sitagliptin. In a pharmacokinetic cohort study, coadministration o |
