Drug General Information (ID: DDIRKTE6UF)
  Drug Name Methylnaltrexone Drug Info Pitolisant Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Peripheral Opioid Receptor Antagonists Cns Stimulants
  Structure

 Mechanism of Methylnaltrexone-Pitolisant Interaction (Severity Level: Moderate)
     Transporter inhibition Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Methylnaltrexone Pitolisant
      Mechanism OCT1 substrate OCT1 inhibitor
      Key Mechanism Factor 1
Factor Name Solute carrier family 22 member 1
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Structure Sequence
MPTVDDILEQVGESGWFQKQAFLILCLLSAAFAPICVGIVFLGFTPDHHCQSPGVAELSQRCGWSPAEELNYTVPGLGPAGEAFLGQCRRYEVDWNQSALSCVDPLASLATNRSHLPLGPCQDGWVYDTPGSSIVTEFNLVCADSWKLDLFQSCLNAGFLFGSLGVGYFADRFGRKLCLLGTVLVNAVSGVLMAFSPNYMSMLLFRLLQGLVSKGNWMAGYTLITEFVGSGSRRTVAIMYQMAFTVGLVALTGLAYALPHWRWLQLAVSLPTFLFLLYYWCVPESPRWLLSQKRNTEAIKIMDHIAQKNGKLPPADLKMLSLEEDVTEKLSPSFADLFRTPRLRKRTFILMYLWFTDSVLYQGLILHMGATSGNLYLDFLYSALVEIPGAFIALITIDRVGRIYPMAMSNLLAGAACLVMIFISPDLHWLNIIIMCVGRMGITIAIQMICLVNAELYPTFVRNLGVMVCSSLCDIGGIITPFIVFRLREVWQALPLILFAVLGLLAAGVTLLLPETKGVALPETMKDAENLGRKAKPKENTIYLKVQTSEPSGT
Gene Name 44835
Uniprot ID S22A1_HUMAN
KEGG Pathway hsa:6580
Protein Family Major facilitator (TC 2.A.1) superfamily
Protein Function
Translocates a broad array of organic cations with various structures and molecular weights including the model compounds 1-methyl-4-phenylpyridinium (MPP), tetraethylammonium (TEA), N-1-methylnicotinamide (NMN), 4-(4-(dimethylamino)styryl)-N-methylpyridinium (ASP), the endogenous compounds choline, guanidine, histamine, epinephrine, adrenaline, noradrenaline and dopamine, and the drugs quinine, and metformin. The transport of organic cations is inhibited by a broad array of compounds like tetramethylammonium (TMA), cocaine, lidocaine, NMDA receptor antagonists, atropine, prazosin, cimetidine, TEA and NMN, guanidine, cimetidine, choline, procainamide, quinine, tetrabutylammonium, and tetrapentylammonium. Translocates organic cations in an electrogenic and pH-independent manner. Translocates organic cations across the plasma membrane in both directions. Transports the polyamines spermine and spermidine. Transports pramipexole across the basolateral membrane of the proximal tubular epithelial cells. The choline transport is activated by MMTS. Regulated by various intracellular signaling pathways including inhibition by protein kinase A activation, and endogenously activation by the calmodulin complex, the calmodulin-dependent kinase II and LCK tyrosine kinase.
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      Mechanism Description
  • Decreased clearance of Methylnaltrexone due to the transporter inhibition by Pitolisant 

Recommended Action
      Management Caution is recommended when pitolisant is administered with OCT1 substrates.

References
1 Cerner Multum, Inc. "UK Summary of Product Characteristics.".