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Interactions between Antihistamines and Antiretrovirals
Antiretroviral (ARV) | Dose of ARV | Dose of Astemizole | Effect on ARV Levels | Effect on Astemizole Levels | Potential Clinical Effects | Mechanism of Interaction | Management |
---|---|---|---|---|---|---|---|
Amprenavir63, 60 (APV)(Agenerase) | - | - | - | Not studied; may increase astemizole levels | Increased astemizole effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by amprenavir | Do not coadminister Alternative Agents: |
Darunavir161 (DRV)(Prezista) | - | - | - | Not studied; may increase astemizole levels | Increased astemizole effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by darunavir/ritonavir | Do not coadminister Alternative Agents: |
Delavirdine88 (DLV)(Rescriptor) | - | - | - | Not studied; may increase astemizole levels | Increased astemizole effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 and 2C9 by delavirdine | Do not coadminister Alternative Agents: |
Efavirenz90 (EFV)(Sustiva) | - | - | - | Not studied; may increase astemizole levels | Increased astemizole effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by efavirenz | Do not coadminister Alternative Agents: |
Indinavir253 (IDV)(Crixivan) | - | - | - | Not studied; may increase astemizole levels | Increased astemizole effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by indinavir | Do not coadminister Alternative Agents: |
Antiretroviral (ARV) | Dose of ARV | Dose of Astemizole | Effect on ARV Levels | Effect on Astemizole Levels | Potential Clinical Effects | Mechanism of Interaction | Management |
Lopinavir/ritonavir78 (LPV/r)(Kaletra) | - | - | - | Not studied; may increase astemizole levels | Increased astemizole effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by lopinavir/ritonavir | Do not coadminister Alternative Agents: |
Nelfinavir254 (NFV)(Viracept) | - | - | - | Not studied; may increase astemizole levels | Increased astemizole effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by nelfinavir | Do not coadminister Alternative Agents: |
Ritonavir178, 55 (RTV)(Norvir) | - | - | - | Not studied; may increase astemizole levels | Increased astemizole effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by ritonavir | Do not coadminister Alternative Agents: |
Saquinavir44 (SQV)(Fortovase, Invirase) | - | - | - | Not studied; may increase astemizole levels | Increased astemizole effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by saquinavir | Do not coadminister Alternative Agents: |
Tipranavir154 (TPV)(Aptivus) | - | - | - | Not studied; may increase astemizole levels | Increased astemizole effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by tipranavir/ritonavir | Do not coadminister Alternative Agents: |
"-" indicates that there are no data available |
Antiretroviral (ARV) | Dose of ARV | Dose of Cetirizine | Effect on ARV Levels | Effect on Cetirizine Levels | Potential Clinical Effects | Mechanism of Interaction | Management |
---|---|---|---|---|---|---|---|
Efavirenz90 (EFV)(Sustiva) | 600 mg x 10 days | 10 mg x 1 dose | No significant change | Cetirizine Cmax: decreased 24% | - | - | No dose adjustment necessary
|
Ritonavir252 (RTV)(Norvir) | 600 mg BID | 10 mg QD | Not studied | Cetirizine AUC: increased 42%; half-life: increased 52%; clearance: decreased 29%; Cmax: no significant change | - | - | No dose adjustment necessary |
"-" indicates that there are no data available |
Antiretroviral (ARV) | Dose of ARV | Dose of Terfenadine | Effect on ARV Levels | Effect on Terfenadine Levels | Potential Clinical Effects | Mechanism of Interaction | Management |
---|---|---|---|---|---|---|---|
Amprenavir63, 60 (APV)(Agenerase) | - | - | - | Not studied; may increase terfenadine levels | Increased terfenadine effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by amprenavir | Do not coadminister Alternative Agents: |
Darunavir161 (DRV)(Prezista) | - | - | - | Not studied; may increase terfenadine levels | Increased astemizole effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by darunavir/ritonavir | Do not coadminister Alternative Agents: |
Delavirdine88 (DLV)(Rescriptor) | - | - | - | Not studied; may increase terfenadine levels | Increased terfenadine effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 and 2C9 by delavirdine | Do not coadminister Alternative Agents: |
Indinavir16 (IDV)(Crixivan) | - | - | - | - | Increased terfenadine effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by indinavir | Do not coadminister Alternative Agents: |
Lopinavir/ritonavir78 (LPV/r)(Kaletra) | - | - | - | Not studied; may increase terfenadine levels | Increased terfenadine effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by lopinavir/ritonavir | Do not coadminister Alternative Agents: |
Antiretroviral (ARV) | Dose of ARV | Dose of Terfenadine | Effect on ARV Levels | Effect on Terfenadine Levels | Potential Clinical Effects | Mechanism of Interaction | Management |
Nelfinavir24 (NFV)(Viracept) | - | - | - | Not studied; may increase terfenadine levels | Increased terfenadine effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by nelfinavir | Do not coadminister Alternative Agents: |
Ritonavir178, 55 (RTV)(Norvir) | - | - | - | Increased terfenadine levels | Increased terfenadine effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by ritonavir | Do not coadminister Alternative Agents: |
Saquinavir44 (SQV)(Fortovase, Invirase) | 1200 mg TID x 4 days | 60 mg BID x 11 days | - | Terfenadine AUC: increased 368%; Cmax: increased 253% | Increased terfenadine effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by saquinavir | Do not coadminister Alternative Agents: |
Tipranavir154 (TPV)(Aptivus) | - | - | - | Not studied; may increase terfenadine levels | Increased terfenadine effects (eg, cardiac arrhythmias) | Inhibition of CYP450 3A4 by tipranavir/ritonavir | Do not coadminister Alternative Agents: |
"-" indicates that there are no data available |