2025 – PAGE 245 – PHARMACOLOGY & DRUG PEARLS
HEPATIC INDUCERS
Hepatic inducers are medications that work to increase the metabolism of certain medications and thus LOWER their effectiveness. Examples include Carbamazepine, Phenobarbital, Phenytoin, Rifampin, and Saint John’s wort.
PEARL: OCPs’ effectiveness is DECREASED with these medications, so recommend a backup method of contraception.
HEPATIC INHIBITORS
Fluconazole (and other -azole), Isoniazid, Sulfonamides, and H2 Blockers (especially cimetidine) are hepatic inhibitors. So are grapefruit juice and erythromycin. Focus on remembering these P450 INHIBITORS more than the inducers.
MNEMONIC: (It’s PG-13) Imagine a racist trucker sitting in a diner drinking grapefruit juice. He sees a THAI DINEr sitting in a booth talking very loudly on her SUL-FONE. He gets mad and turns as cold as ICE. He then climbs up onto a BLOCK of wood, bends over, and starts shooting cubes/BLOCKS of ICE out of his AZOLE. His aim is pretty good, and he completely knocks the SUL-FONE out of the THAI DINEr’s hand!
- KEY:
- THAI DINEr should help you think of “ti-dine,” as in cimeTIDINE
- SUL-FONE (cell phone) should remind you of SULFONamides.
- BLOCK might help you remember that this mnemonic deals with BLOCKING of Cytochrome P450.
- ICE should help you remember ICE-oniazid/isoniazid.
- AZOLE should help you remember fluconAZOLE and itraconAZOLE.
ALTERNATIVE MEDICATIONS
- JOHN’S WORT INDUCES P450. This alternative medication can pose a problem for patients on OCPs, digoxin, HIV medications, or Warfarin.
- GINSENGinteracts with numerous drugs, including aspirin, warfarin, diuretics, and steroids. It also decreases blood glucose.
- MNEMONIC: Gin-SING interacts with just about everyTHING! If you see it in the history, it’s probably related to your answer.
- GINKGO may also decrease blood glucose and increase bleeding risk when used with aspirin or other anti-clotting drugs.
INTRAUTERINE DRUG EXPOSURES
COCAINE EXPOSURE
Premature birth is common with prenatal cocaine exposure. Surprisingly there are minimal withdrawal symptoms.
MNEMONIC: Somewhat of a “reverse mnemonic,” but given that the withdrawal symptoms are minimal, if you ever hear a NICU nurse refer to a screaming and shivering newborn as a “crack baby,” be sure to educate her (or him) on the fact that the term is a misnomer.