The metabolism of Dextromethorphan can be decreased when combined with Cinacalcet. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Asenapine. The risk or severity of adverse effects can be increased when Methadone is combined with Dextromethorphan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Acepromazine. Octamoxin may increase the serotonergic activities of Dextromethorphan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Triflupromazine. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Linezolid. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Chlorprothixene. Tranylcypromine may increase the serotonergic activities of Dextromethorphan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Loxapine. The risk or severity of adverse effects can be increased when Protriptyline is combined with Dextromethorphan. The serum concentration of Conivaptan can be increased when it is combined with Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Indinavir. The risk or severity of adverse effects can be increased when Zolmitriptan is combined with Dextromethorphan. The risk or severity of adverse effects can be increased when Tramadol is combined with Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Cyclosporine. The metabolism of Dextromethorphan can be decreased when combined with Gemfibrozil. The metabolism of Dextromethorphan can be increased when combined with Rifampicin. The metabolism of Dextromethorphan can be decreased when combined with Atazanavir. Toloxatone may increase the serotonergic activities of Dextromethorphan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Doxepin. The serum concentration of Dextromethorphan can be increased when it is combined with Luliconazole. Trans-2-Phenylcyclopropylamine may increase the serotonergic activities of Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Haloperidol. The metabolism of Dextromethorphan can be increased when combined with Rifapentine. The metabolism of Dextromethorphan can be decreased when combined with Chloroquine. Alaproclate may increase the serotonergic activities of Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Diltiazem. Nefazodone may increase the serotonergic activities of Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Isavuconazonium. The serum concentration of Dextromethorphan can be decreased when it is combined with Bosentan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Olanzapine. The metabolism of Dextromethorphan can be decreased when combined with Losartan. Pargyline may increase the serotonergic activities of Dextromethorphan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Droperidol. Sertraline may increase the serotonergic activities of Dextromethorphan. The serum concentration of Dextromethorphan can be decreased when it is combined with Siltuximab. The metabolism of Dextromethorphan can be decreased when combined with Bupropion. The serum concentration of Dextromethorphan can be increased when it is combined with Palbociclib. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Fencamfamine. The metabolism of Dextromethorphan can be decreased when combined with Midostaurin. Moclobemide may increase the serotonergic activities of Dextromethorphan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Risperidone. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Clomipramine. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Frovatriptan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Trimipramine. The serum concentration of Pazopanib can be increased when it is combined with Dextromethorphan. Benmoxin may increase the serotonergic activities of Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Nicotine. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Quetiapine. The serum concentration of the active metabolites of Dabigatran etexilate can be increased when Dabigatran etexilate is used in combination with Dextromethorphan. The serum concentration of Dextromethorphan can be increased when it is combined with Panobinostat. The metabolism of Dextromethorphan can be decreased when combined with Valproic Acid. L-Tryptophan may increase the serotonergic activities of Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Boceprevir. The metabolism of Dextromethorphan can be decreased when combined with Delavirdine. The metabolism of Dextromethorphan can be decreased when combined with Isradipine. The serum concentration of Everolimus can be increased when it is combined with Dextromethorphan. The serum concentration of Dextromethorphan can be increased when it is combined with Darunavir. The metabolism of Dextromethorphan can be increased when combined with Phenobarbital. Harmaline may increase the serotonergic activities of Dextromethorphan. The serum concentration of Dextromethorphan can be increased when it is combined with Netupitant. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Flupentixol. The metabolism of Dextromethorphan can be decreased when combined with Lovastatin. Nialamide may increase the serotonergic activities of Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Lapatinib. The serum concentration of Prucalopride can be increased when it is combined with Dextromethorphan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Trifluoperazine. The metabolism of Dextromethorphan can be decreased when combined with Nicardipine. The metabolism of Dextromethorphan can be decreased when combined with Esomeprazole. The metabolism of Dextromethorphan can be decreased when combined with Clotrimazole. The metabolism of Dextromethorphan can be decreased when combined with Artemether. The metabolism of Dextromethorphan can be decreased when combined with Nilotinib. The serum concentration of Ranolazine can be increased when it is combined with Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Sulfadiazine. The metabolism of Dextromethorphan can be decreased when combined with Doxycycline. The metabolism of Dextromethorphan can be decreased when combined with Ritonavir. The serum concentration of Colchicine can be increased when it is combined with Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Lopinavir. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Molindone. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Aceprometazine. The metabolism of Dextromethorphan can be decreased when combined with Atomoxetine. Minaprine may increase the serotonergic activities of Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Fluconazole. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Perazine. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Desipramine. The metabolism of Dextromethorphan can be decreased when combined with Ziprasidone. Ondansetron may increase the serotonergic activities of Dextromethorphan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Benperidol. The risk or severity of adverse effects can be increased when Eletriptan is combined with Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Topiramate. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Amisulpride. The metabolism of Dextromethorphan can be decreased when combined with Irbesartan. The serum concentration of Dextromethorphan can be increased when it is combined with Mifepristone. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Ecopipam. Pivhydrazine may increase the serotonergic activities of Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Terbinafine. The serum concentration of Naloxegol can be increased when it is combined with Dextromethorphan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Ergoloid mesylate. The serum concentration of Brentuximab vedotin can be increased when it is combined with Dextromethorphan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Lurasidone. The serum concentration of Dextromethorphan can be increased when it is combined with Vemurafenib. The serum concentration of Dextromethorphan can be decreased when it is combined with Peginterferon alfa-2b. The risk or severity of adverse effects can be increased when Pethidine is combined with Dextromethorphan. Levomilnacipran may increase the serotonergic activities of Dextromethorphan. The serum concentration of Dextromethorphan can be increased when it is combined with Ivacaftor. The serum concentration of Edoxaban can be increased when it is combined with Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Verapamil. The risk or severity of adverse effects can be increased when Imipramine is combined with Dextromethorphan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Nortriptyline. Furazolidone may increase the serotonergic activities of Dextromethorphan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Ritanserin. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Zuclopenthixol. The serum concentration of Afatinib can be increased when it is combined with Dextromethorphan. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Amoxapine. The metabolism of Dextromethorphan can be decreased when combined with Leflunomide. The serum concentration of Ledipasvir can be increased when it is combined with Dextromethorphan. Pheniprazine may increase the serotonergic activities of Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Zucapsaicin. The metabolism of Dextromethorphan can be decreased when combined with Rolapitant. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Pipamperone. The metabolism of Dextromethorphan can be decreased when combined with Pantoprazole. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Lithium. The metabolism of Dextromethorphan can be decreased when combined with Eslicarbazepine acetate. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Tiapride. The metabolism of Dextromethorphan can be decreased when combined with Chloramphenicol. Indalpine may increase the serotonergic activities of Dextromethorphan. The metabolism of Dextromethorphan can be decreased when combined with Clopidogrel. The metabolism of Dextromethorphan can be decreased when combined with Sulfisoxazole. Caroxazone may increase the serotonergic activities of Dextromethorphan.