Details of Drug Interaction

Details of Drug-Drug Interaction

 Drug General Information (ID: DDIUCYOW8D)
  Drug Name Atomoxetine Drug Info Terbinafine Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Cns Stimulants/Adrenergic Uptake Inhibitors Antifungal Agents
  Structure

 Mechanism of Atomoxetine-Terbinafine Interaction (Severity Level: Moderate)
     CYP450 enzyme inhibition Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Atomoxetine Terbinafine
      Mechanism CYP450 2D6 substrate CYP450 2D6 inhibitor
      Key Mechanism Factor 1
Factor Name Cytochrome P450 2D6
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Structure Sequence
MGLEALVPLAVIVAIFLLLVDLMHRRQRWAARYPPGPLPLPGLGNLLHVDFQNTPYCFDQLRRRFGDVFSLQLAWTPVVVLNGLAAVREALVTHGEDTADRPPVPITQILGFGPRSQGVFLARYGPAWREQRRFSVSTLRNLGLGKKSLEQWVTEEAACLCAAFANHSGRPFRPNGLLDKAVSNVIASLTCGRRFEYDDPRFLRLLDLAQEGLKEESGFLREVLNAVPVLLHIPALAGKVLRFQKAFLTQLDELLTEHRMTWDPAQPPRDLTEAFLAEMEKAKGNPESSFNDENLRIVVADLFSAGMVTTSTTLAWGLLLMILHPDVQRRVQQEIDDVIGQVRRPEMGDQAHMPYTTAVIHEVQRFGDIVPLGVTHMTSRDIEVQGFRIPKGTTLITNLSSVLKDEAVWEKPFRFHPEHFLDAQGHFVKPEAFLPFSAGRRACLGEPLARMELFLFFTSLLQHFSFSVPTGQPRPSHHGVFAFLVSPSPYELCAVPR
Gene Name CYP2D6
Uniprot ID CP2D6_HUMAN
KEGG Pathway hsa:1565
Protein Family Cytochrome P450 family
Protein Function
A cytochrome P450 monooxygenase involved in the metabolism of fatty acids, steroids and retinoids (PubMed:18698000, PubMed:19965576, PubMed:20972997, PubMed:21289075, PubMed:21576599). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (NADPH--hemoprotein reductase) (PubMed:18698000, PubMed:19965576, PubMed:20972997, PubMed:21289075, PubMed:21576599). Catalyzes the epoxidation of double bonds of polyunsaturated fatty acids (PUFA) (PubMed:19965576, PubMed:20972997). Metabolizes endocannabinoid arachidonoylethanolamide (anandamide) to 20-hydroxyeicosatetraenoic acid ethanolamide (20-HETE-EA) and 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acid ethanolamides (EpETrE-EAs), potentially modulating endocannabinoid system signaling (PubMed:18698000, PubMed:21289075). Catalyzes the hydroxylation of carbon-hydrogen bonds. Metabolizes cholesterol toward 25-hydroxycholesterol, a physiological regulator of cellular cholesterol homeostasis (PubMed:21576599). Catalyzes the oxidative transformations of all-trans retinol to all-trans retinal, a precursor for the active form all-trans-retinoic acid (PubMed:10681376). Also involved in the oxidative metabolism of drugs such as antiarrhythmics, adrenoceptor antagonists, and tricyclic antidepressants.
    Click to Show/Hide
      Mechanism Description
  • Decreased metabolism of Atomoxetine caused by Terbinafine mediated inhibition of CYP450 enzyme

Recommended Action
      Management Pharmacologic response to atomoxetine should be monitored more closely whenever a CYP450 2D6 inhibitor is added to or withdrawn from therapy, as dosage adjustment of atomoxetine may be necessary in extensive metabolizers. During coadministration, patients should be advised to contact their physician if they experience excessive adverse effects of atomoxetine such as dizziness, dry mouth, anorexia, sleep disturbances, and palpitations.

References
1 Belle DJ, Ernest CS, Sauer JM, Smith BP, Thomasson HR, Witcher JW "Effect of potent CYP2D6 inhibition by paroxetine on atomoxetine pharmacokinetics." J Clin Pharmacol 42 (2002): 1219-27. [PMID: 12412820]
2 Product Information. Qelbree (viloxazine). Supernus Pharmaceuticals Inc, Rockville, MD.
3 Product Information. Strattera (atomoxetine). Lilly, Eli and Company, Indianapolis, IN.