Zimelidine may increase the serotonergic activities of Olanzapine. Olanzapine may increase the QTc-prolonging activities of Promazine. Olanzapine may increase the QTc-prolonging activities of Telithromycin. Iproniazid may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Efavirenz. The risk or severity of adverse effects can be increased when Olanzapine is combined with Fencamfamine. Olanzapine can cause a decrease in the absorption of Iron resulting in a reduced serum concentration and potentially a decrease in efficacy. Olanzapine may increase the QTc-prolonging activities of Levofloxacin. 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 Tiapride. The risk or severity of adverse effects can be increased when Dextromethorphan is combined with Olanzapine. The serum concentration of Ketoconazole can be decreased when it is combined with Olanzapine. The metabolism of Olanzapine can be decreased when combined with Diphenhydramine. The risk or severity of adverse effects can be increased when Ergonovine is combined with Olanzapine. Olanzapine may increase the QTc-prolonging activities of Sotalol. The serum concentration of Gefitinib can be decreased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Chlorphenamine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Ritanserin. The risk or severity of adverse effects can be increased when BL-1020 is combined with Olanzapine. The serum concentration of Tolvaptan can be increased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Pirenzepine is combined with Olanzapine. The risk or severity of adverse effects can be increased when Zolmitriptan is combined with Olanzapine. Mebanazine may increase the serotonergic activities of Olanzapine. Brimonidine may increase the central nervous system depressant (CNS depressant) activities of Olanzapine. The risk or severity of adverse effects can be increased when Naratriptan is combined with Olanzapine. The therapeutic efficacy of Dulaglutide can be decreased when used in combination with Olanzapine. The serum concentration of Olanzapine can be decreased when it is combined with Valproic Acid. The therapeutic efficacy of Mitiglinide can be decreased when used in combination with Olanzapine. 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 Methapyrilene. The risk or severity of adverse effects can be increased when Codeine is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Levorphanol. The metabolism of Olanzapine can be decreased when combined with Rucaparib. The risk or severity of adverse effects can be increased when Olanzapine is combined with Procaine. The risk or severity of adverse effects can be increased when Pentobarbital is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Methsuximide. The risk or severity of adverse effects can be increased when Olanzapine is combined with Meclizine. The therapeutic efficacy of Gliquidone can be decreased when used in combination with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Zaleplon. The risk or severity of adverse effects can be increased when Olanzapine is combined with Tiagabine. Olanzapine may increase the antipsychotic activities of Amisulpride. The therapeutic efficacy of Levodopa can be decreased when used in combination with Olanzapine. 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 Dihydromorphine. The risk or severity of adverse effects can be increased when Prazepam is combined with Olanzapine. The therapeutic efficacy of Cysteamine can be decreased when used in combination with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Felbamate. Olanzapine may increase the sedative activities of Rotigotine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Amperozide. The serum concentration of Rosuvastatin can be increased when it is combined with Olanzapine. The metabolism of Olanzapine can be decreased when combined with Lidocaine. Hydracarbazine may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Tramadol is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Trimipramine. The serum concentration of Dabrafenib can be decreased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Vilazodone is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Carbamazepine. The metabolism of Olanzapine can be decreased when combined with Cholecalciferol. The risk or severity of adverse effects can be increased when Olanzapine is combined with Alfaxalone. The therapeutic efficacy of Voglibose can be decreased when used in combination with Olanzapine. Lamotrigine may increase the sedative activities of Olanzapine. The metabolism of Olanzapine can be decreased when combined with Isoniazid. The metabolism of Olanzapine can be decreased when combined with Zucapsaicin. The risk or severity of adverse effects can be increased when Olanzapine is combined with Topiramate. The risk or severity of adverse effects can be increased when Olanzapine is combined with Carbinoxamine. The risk or severity of adverse effects can be increased when Sumatriptan is combined with Olanzapine. The metabolism of Tacrolimus can be decreased when combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Phenoxyethanol. The serum concentration of Olanzapine can be decreased when it is combined with Teriflunomide. The serum concentration of Varenicline can be increased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Promethazine is combined with Olanzapine. The therapeutic efficacy of Miglitol can be decreased when used in combination with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Gamma Hydroxybutyric Acid. Olanzapine may increase the QTc-prolonging activities of Erythromycin. The risk or severity of adverse effects can be increased when Dihydroergotamine is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Gabapentin. The metabolism of Olanzapine can be decreased when combined with Mirabegron. The risk or severity of adverse effects can be increased when Olanzapine is combined with Articaine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Normethadone. The risk or severity of adverse effects can be increased when Clobazam is combined with Olanzapine. Olanzapine may increase the QTc-prolonging activities of Anagrelide. Olanzapine may increase the QTc-prolonging activities of Quinine. The risk or severity of adverse effects can be increased when Metoclopramide is combined with Olanzapine. Olanzapine may increase the QTc-prolonging activities of Cisapride. 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 Midazolam is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Methoxyflurane. The therapeutic efficacy of Alogliptin can be decreased when used in combination with Olanzapine. The therapeutic efficacy of Empagliflozin can be decreased when used in combination with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Primidone. Pivhydrazine may increase the serotonergic activities of Olanzapine. Nialamide may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Lorazepam is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Ramelteon. Phenoxypropazine may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Ethyl chloride. Sertraline may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Thiothixene. The serum concentration of Olanzapine can be decreased when it is combined with Osimertinib. The risk or severity of adverse effects can be increased when Olanzapine is combined with Levomethadyl Acetate. The risk or severity of adverse effects can be increased when Morphine is combined with Olanzapine. The risk or severity of adverse effects can be increased when Diazepam is combined with Olanzapine. Olanzapine may increase the arrhythmogenic activities of Mequitazine. Pirlindole may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Allopregnanolone. The risk or severity of adverse effects can be increased when Camazepam is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Cinchocaine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Carisoprodol. The therapeutic efficacy of Buformin can be decreased when used in combination with Olanzapine. The therapeutic efficacy of Insulin Detemir can be decreased when used in combination with Olanzapine. The therapeutic efficacy of Sulodexide can be decreased when used in combination with Olanzapine. The risk or severity of adverse effects can be increased when Flumazenil is combined with Olanzapine. Mifepristone may increase the QTc-prolonging activities of Olanzapine. The serum concentration of Olanzapine can be increased when it is combined with Ranolazine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Methadyl Acetate. Olanzapine may decrease the stimulatory activities of Pseudoephedrine. The serum concentration of Tizanidine can be increased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Dihydroetorphine. The serum concentration of Thioridazine can be increased when it is combined with Olanzapine. The serum concentration of Olanzapine can be increased when it is combined with Vemurafenib. The risk or severity of adverse effects can be increased when CE-326597 is combined with Olanzapine. Olanzapine may increase the QTc-prolonging activities of Vandetanib. The risk or severity of adverse effects can be increased when Olanzapine is combined with Dapiprazole. Hydroxyzine may increase the central nervous system depressant (CNS depressant) activities of Olanzapine. The risk or severity of adverse effects can be increased when Lormetazepam is combined with Olanzapine. Olanzapine may increase the sedative activities of Ropinirole. Olanzapine can cause a decrease in the absorption of Iron saccharate resulting in a reduced serum concentration and potentially a decrease in efficacy. The therapeutic efficacy of Deoxyspergualin can be decreased when used in combination with Olanzapine. The metabolism of Olanzapine can be decreased when combined with Clobazam. The therapeutic efficacy of Canagliflozin can be decreased when used in combination with Olanzapine.