Table 2.
Examples of potential pharmacokinetic interactions affecting drugs that prolong the QT interval, inhibit cytochrome P450 (CYP) inhibitors, or both
| CYP isoform affected | |||
|---|---|---|---|
| CYP1A2 | CYP2D6 | CYP3A4 | |
| QT prolonging drugs | Haloperidol | Amitriptyline | Erythromycin |
| Amitriptyline | Haloperidol | SSRIs† | |
| Imipramine | Imipramine | Amiodarone | |
| Quinidine | Cisapride | ||
| Haloperidol | |||
| Quinidine | |||
| Pimozide | |||
| Methadone | |||
| CYP inhibitors | Fluoroquinolones* | Ritonavir | Protease inhibitors |
| Cimetidine | SSRIs* | Imidazole fungicides* | |
| Amiodarone* | Amiodarone* | Diltiazem | |
| Grapefruit juice | Quinidine* | SSRIs†, * | |
| Methadone* | Erythromycin* | ||
| Grapefruit juice | |||
*
May also prolong QT interval.
†
Selective serotonin re‐uptake inhibitors.