**[List of drugs that may have potential CYP2C19 interactions]{.mark}**

#### CYP2C19 Substrates

+-----------------+-----------------+-----------------+-----------------+
| Carisoprodol    | Escitalopram    | Methsuximide    | Phenobarbital   |
|                 |                 |                 |                 |
| [Cil            | Esomeprazole    | [Mocl           | Phenytoin       |
| ostazol]{.mark} |                 | obemide]{.mark} |                 |
|                 | Fosphenytoin    |                 | Progesterone    |
| Citalopram      |                 | Nelfinavir      |                 |
|                 | Imipramine      |                 | Rabeprazole     |
| [C              |                 | Nilutamide      |                 |
| lobazam]{.mark} | Lansoprazole    |                 | Sertraline      |
|                 |                 | Omeprazole      |                 |
| Clomipramine    | Mephenytoin     |                 | Trimipramine    |
|                 |                 | Pantoprazole    |                 |
| Desogestrel     | Mephobarbital   |                 | Voriconazole    |
|                 |                 | Pentamidine     |                 |
| Diazepam        |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+

**CYP2C19 Inhibitors**

+-----------------+-----------------+-----------------+-----------------+
| Amiodarone      | Felbamate       | Methoxsalen     | Ritonavir       |
|                 |                 |                 |                 |
| Amitriptyline   | [Feno           | Methsuximide    | Rosiglitazone   |
|                 | fibrate]{.mark} |                 |                 |
| Amprenavir      |                 | Miconazole      | Saquinavir      |
|                 | Fluconazole     |                 |                 |
| [Apr            |                 | [Mocl           | Selegiline      |
| epitant]{.mark} | Fluoxetine      | obemide]{.mark} |                 |
|                 |                 |                 | Sertraline      |
| Azelastine      | Fluvoxamine     | Modafinil       |                 |
|                 |                 |                 | Sildenafil      |
| Bortezomib      | Fosamprenavir   | Nelfinavir      |                 |
|                 |                 |                 | Sulconazole     |
| Buprenorphine   | Gefitinib       | Nicardipine     |                 |
|                 |                 |                 | Telmisartan     |
| Cholecal        | Gemfibrozil     | Nilutamide      |                 |
| ciferol/Vitamin |                 |                 | Ticlopidine     |
| D~3~            | Imipramine      | Olanzapine      |                 |
|                 |                 |                 | Tioconazole     |
| Cimetidine      | Indinavir       | Omeprazole      |                 |
|                 |                 |                 | Topiramate      |
| Citalopram      | Indomethacin    | Orphenadrine    |                 |
|                 |                 |                 | Torsemide       |
| Clotrimazole    | Isoniazid       | Oxcarbazepine   |                 |
|                 |                 |                 | Tranylcypromine |
| Clozapine       | Ketoconazole    | Paroxetine      |                 |
|                 |                 |                 | Valdecoxib      |
| Delavirdine     | Lansoprazole    | Pentamidine     |                 |
|                 |                 |                 | Valproic acid   |
| Diazepam        | Letrozole       | Pimozide        |                 |
|                 |                 |                 | Voriconazole    |
| Dimethyl        | Loratadine      | Pioglitazone    |                 |
| sulfoxide       |                 |                 | Warfarin        |
|                 | Losartan        | Probenecid      |                 |
| Drospirenone    |                 |                 | Zafirlukast     |
|                 | Mephobarbital   | Progesterone    |                 |
| Efavirenz       |                 |                 |                 |
|                 | Mestranol       | Propofol        |                 |
| Entacapone      |                 |                 |                 |
|                 | Methimazole     | Rabeprazole     |                 |
| Ethinyl         |                 |                 |                 |
| estradiol       |                 |                 |                 |
|                 |                 |                 |                 |
| Ethotoin        |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+

**CYP2C19 Inducers**

+-----------------+-----------------+-----------------+-----------------+
| Am              | Fosphenytoin    | Rifampin        | St. John's wort |
| inoglutethimide |                 |                 | (1)             |
|                 | Phenytoin       |                 |                 |
| Carbamazepine   |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+

When drugs classified as 'substrates' are co-administered with *[(Study
Agent)]{.underline}*, there is the potential for higher concentrations
of the 'substrate'. When *[(Study Agent)]{.underline}* is
co-administered with compounds classified as 'inhibitors', increased
plasma concentrations of *[(Study Agent)]{.underline}* is the potential
outcome. The co-administration of 'inducers' would potentially lower
plasma *[(Study Agent)]{.underline}* concentrations.

[Note: Adapted from Cytochrome P450 Enzymes: Substrates, Inhibitors, and
Inducers. In: Lacy CF, Armstrong LL, Goldman MP, Lance LL eds. Drug
Information Handbook 15^TH^ ed. Hudson, OH; LexiComp Inc. 2007:
1899-1912.]{.mark}

[Only major substrates and effective inducers are listed.]{.mark}

[Additional information for drug interactions with cytochrome P450
isoenzymes can be found at
<http://medicine.iupui.edu/flockhart/>.]{.mark}

\(1\) Wang *et al*. (2004). *Clin Pharmacol Ther*. 75:191-197

[Updated on May 1, 2007]{.mark}