The risk or severity of adverse effects can be increased when Olanzapine is combined with Metaxalone. Phenoxypropazine may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Ketobemidone. The risk or severity of adverse effects can be increased when Phenelzine is combined with Olanzapine. Olanzapine may increase the QTc-prolonging activities of Methadone. The risk or severity of adverse effects can be increased when Alimemazine is combined with Olanzapine. Olanzapine may decrease the stimulatory activities of Hydroxyamphetamine. The therapeutic efficacy of Levodopa can be decreased when used in combination with Olanzapine. Venlafaxine may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Phenobarbital. The risk or severity of adverse effects can be increased when Olanzapine is combined with Gabapentin Enacarbil. The risk or severity of adverse effects can be increased when Clorazepate is combined with Olanzapine. Olanzapine may decrease the stimulatory activities of Mephedrone. The risk or severity of adverse effects can be increased when Olanzapine is combined with Trichloroethylene. Sodium oxybate may increase the central nervous system depressant (CNS depressant) activities of Olanzapine. Olanzapine may increase the QTc-prolonging activities of Sulfisoxazole. The risk or severity of adverse effects can be increased when Olanzapine is combined with Bupivacaine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Cetirizine. Dapoxetine may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Ezogabine. The therapeutic efficacy of Quinagolide can be decreased when used in combination with Olanzapine. The serum concentration of Olanzapine can be increased when it is combined with Deferasirox. The therapeutic efficacy of AICA ribonucleotide can be decreased when used in combination with Olanzapine. Olanzapine may increase the antipsychotic activities of Sulpiride. Olanzapine can cause a decrease in the absorption of Dasatinib resulting in a reduced serum concentration and potentially a decrease in efficacy. The risk or severity of adverse effects can be increased when Olanzapine is combined with Barbital. The risk or severity of adverse effects can be increased when Netazepide is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Norflurane. The risk or severity of adverse effects can be increased when Olanzapine is combined with Isoflurane. The metabolism of Olanzapine can be decreased when combined with Bortezomib. Olanzapine may increase the QTc-prolonging activities of Levofloxacin. Indalpine may increase the serotonergic activities of Olanzapine. The serum concentration of Pitavastatin can be increased when it is combined with Olanzapine. The serum concentration of Ibrutinib can be increased when it is combined with Olanzapine. The serum concentration of Olanzapine can be decreased when it is combined with Lumacaftor. The risk or severity of adverse effects can be increased when Acepromazine is combined with Olanzapine. The metabolism of Olanzapine can be decreased when combined with Fluvoxamine. Olanzapine may increase the QTc-prolonging activities of Granisetron. Lamotrigine may increase the sedative activities of Olanzapine. Olanzapine may decrease the stimulatory activities of Benzphetamine. The serum concentration of Bosutinib can be decreased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Reserpine is combined with Olanzapine. The risk or severity of adverse effects can be increased when Nitrazepam is combined with Olanzapine. The risk or severity of adverse effects can be increased when Methylene blue is combined with Olanzapine. The risk or severity of adverse effects can be increased when Codeine is combined with Olanzapine. Olanzapine may increase the QTc-prolonging activities of Fluoxetine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Doxepin. The therapeutic efficacy of Bempedoic acid can be decreased when used in combination with Olanzapine. The metabolism of Olanzapine can be decreased when combined with Desipramine. The risk or severity of adverse effects can be increased when SJG-136 is combined with Olanzapine. The metabolism of Olanzapine can be decreased when combined with Cimetidine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Sepranolone. Olanzapine may increase the QTc-prolonging activities of Clarithromycin. The risk or severity of adverse effects can be increased when Olanzapine is combined with Brompheniramine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Raclopride. The therapeutic efficacy of Gliclazide can be decreased when used in combination with Olanzapine. The serum concentration of Itraconazole can be decreased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Oxprenolol. Olanzapine may increase the central nervous system depressant (CNS depressant) activities of Azelastine. The serum concentration of Olanzapine can be increased when it is combined with Cobicistat. The risk or severity of adverse effects can be increased when Olanzapine is combined with Diphenoxylate. Benmoxin may increase the serotonergic activities of Olanzapine. Harmaline may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Fluspirilene. Hydroxyzine may increase the central nervous system depressant (CNS depressant) activities of Olanzapine. The therapeutic efficacy of 2,4-thiazolidinedione can be decreased when used in combination with Olanzapine. Olanzapine may decrease the stimulatory activities of Pseudoephedrine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Opium. Olanzapine may increase the QTc-prolonging activities of Cisapride. Olanzapine can cause a decrease in the absorption of Delavirdine resulting in a reduced serum concentration and potentially a decrease in efficacy. Olanzapine can cause a decrease in the absorption of Iron saccharate resulting in a reduced serum concentration and potentially a decrease in efficacy. The risk or severity of adverse effects can be increased when Procarbazine is combined with Olanzapine. The serum concentration of Cefditoren can be decreased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Adipiplon. The risk or severity of adverse effects can be increased when Olanzapine is combined with Eltanolone. The therapeutic efficacy of Cysteamine can be decreased when used in combination with Olanzapine. The metabolism of Olanzapine can be decreased when combined with Lidocaine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Trimipramine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Levorphanol. The serum concentration of Olanzapine can be increased when it is combined with Darunavir. The risk or severity of adverse effects can be increased when Olanzapine is combined with Oxymorphone. The risk or severity of adverse effects can be increased when Olanzapine is combined with Protriptyline. The risk or severity of adverse effects can be increased when Olanzapine is combined with Methapyrilene. The therapeutic efficacy of Vildagliptin can be decreased when used in combination with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Propofol. The risk or severity of adverse effects can be increased when Olanzapine is combined with Etifoxine. Olanzapine may increase the QTc-prolonging activities of Artemether. The risk or severity of adverse effects can be increased when Olanzapine is combined with Levocetirizine. The metabolism of Olanzapine can be decreased when combined with Tranylcypromine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Amobarbital. The risk or severity of adverse effects can be increased when Olanzapine is combined with Aceprometazine. Olanzapine may increase the QTc-prolonging activities of Primaquine. The serum concentration of Olanzapine can be increased when it is combined with Ranolazine. The serum concentration of Saquinavir can be increased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Amoxapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Primidone. The risk or severity of adverse effects can be increased when Prazepam is combined with Olanzapine. The metabolism of Olanzapine can be decreased when combined with Clemastine. The risk or severity of adverse effects can be increased when Isocarboxazid is combined with Olanzapine. Olanzapine may decrease the stimulatory activities of 2,5-Dimethoxy-4-ethylamphetamine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Ethyl chloride. Nialamide may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Proparacaine. The risk or severity of adverse effects can be increased when Frovatriptan is combined with Olanzapine. The risk or severity of adverse effects can be increased when BMS-906024 is combined with Olanzapine. Olanzapine may increase the QTc-prolonging activities of Lopinavir. Olanzapine may increase the QTc-prolonging activities of Ziprasidone. Olanzapine may increase the QTc-prolonging activities of Chlorpromazine. The metabolism of Olanzapine can be decreased when combined with Zucapsaicin. The therapeutic efficacy of Saxagliptin can be decreased when used in combination with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Zonisamide. The serum concentration of Rosuvastatin can be increased when it is combined with Olanzapine. Olanzapine may decrease the stimulatory activities of Diethylpropion. The risk or severity of adverse effects can be increased when Olanzapine is combined with Halothane. The serum concentration of Olanzapine can be decreased when it is combined with Valproic Acid. The risk or severity of adverse effects can be increased when Moricizine is combined with Olanzapine. Safrazine may increase the serotonergic activities of Olanzapine. The therapeutic efficacy of Tolbutamide can be decreased when used in combination with Olanzapine. The metabolism of Tacrolimus can be decreased when combined with Olanzapine. The metabolism of Olanzapine can be decreased when combined with Darifenacin. The metabolism of Olanzapine can be decreased when combined with Dosulepin. The risk or severity of adverse effects can be increased when Olanzapine is combined with Dyclonine. Olanzapine may increase the central nervous system depressant (CNS depressant) activities of Hydrocodone. The risk or severity of adverse effects can be increased when Olanzapine is combined with Phenytoin. The therapeutic efficacy of Tolazamide can be decreased when used in combination with Olanzapine. The risk or severity of adverse effects can be increased when Clonazepam is combined with Olanzapine. Olanzapine may increase the QTc-prolonging activities of Procainamide. Toloxatone may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Cabergoline is combined with Olanzapine. The risk or severity of adverse effects can be increased when Hydromorphone is combined with Olanzapine.