The risk or severity of adverse effects can be increased when Morphine is combined with Olanzapine. The therapeutic efficacy of Bromocriptine can be decreased when used in combination with Olanzapine. Olanzapine may increase the QTc-prolonging activities of Methadone. The serum concentration of Erlotinib can be decreased when it is combined with Olanzapine. The therapeutic efficacy of Pioglitazone can be decreased when used in combination with Olanzapine. The therapeutic efficacy of Sitagliptin can be decreased when used in combination with Olanzapine. Furazolidone may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Osanetant. The risk or severity of adverse effects can be increased when Olanzapine is combined with Phenytoin. Olanzapine may increase the sedative activities of Ropinirole. Olanzapine may increase the QTc-prolonging activities of Dofetilide. Olanzapine may increase the QTc-prolonging activities of Perflutren. The serum concentration of Olanzapine can be decreased when it is combined with Cyproterone acetate. The risk or severity of adverse effects can be increased when Olanzapine is combined with Ethylmorphine. Olanzapine may decrease the stimulatory activities of Mephedrone. The risk or severity of adverse effects can be increased when Olanzapine is combined with Dextropropoxyphene. 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 Olanzapine is combined with Fentanyl. Lithium may increase the neurotoxic activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Opium. The risk or severity of adverse effects can be increased when Olanzapine is combined with Fospropofol. The therapeutic efficacy of Apomorphine can be decreased when used in combination with Olanzapine. Olanzapine may increase the QTc-prolonging activities of Goserelin. The metabolism of Olanzapine can be decreased when combined with Lorcaserin. 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 Mesoridazine is combined with Olanzapine. The serum concentration of Ibrutinib can be increased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Metaxalone. The metabolism of Olanzapine can be decreased when combined with Bupropion. The risk or severity of adverse effects can be increased when Olanzapine is combined with Nitrous oxide. The risk or severity of adverse effects can be increased when Olanzapine is combined with Pentazocine. Brofaromine may increase the serotonergic activities of Olanzapine. The metabolism of Olanzapine can be decreased when combined with Clemastine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Methylphenidate. The risk or severity of adverse effects can be increased when Clonazepam is combined with Olanzapine. The risk or severity of adverse effects can be increased when Prochlorperazine is combined with Olanzapine. Pirlindole may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Zopiclone. The risk or severity of adverse effects can be increased when Olanzapine is combined with Desloratadine. The metabolism of Olanzapine can be decreased when combined with Diphenhydramine. Olanzapine may increase the QTc-prolonging activities of Vandetanib. 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 Olanzapine is combined with Zaleplon. The serum concentration of Olanzapine can be decreased when it is combined with Peginterferon alfa-2b. The metabolism of Olanzapine can be decreased when combined with Imipramine. Brimonidine may increase the central nervous system depressant (CNS depressant) activities of Olanzapine. The metabolism of Olanzapine can be decreased when combined with Nevirapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Nalbuphine. Olanzapine may decrease the stimulatory activities of Diethylpropion. The risk or severity of adverse effects can be increased when Oxazepam is combined with Olanzapine. The risk or severity of adverse effects can be increased when Tramadol is combined with Olanzapine. 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 Tiapride. The risk or severity of adverse effects can be increased when Olanzapine is combined with Olopatadine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Clidinium. Sodium oxybate may increase the central nervous system depressant (CNS depressant) activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Ethosuximide. Safrazine may increase the serotonergic activities of Olanzapine. The metabolism of Olanzapine can be decreased when combined with Clotrimazole. The risk or severity of adverse effects can be increased when Sumatriptan is combined with Olanzapine. The metabolism of Olanzapine can be decreased when combined with Manidipine. The serum concentration of Ketoconazole can be decreased when it is combined with Olanzapine. 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 Methadyl Acetate. The serum concentration of Fosamprenavir can be decreased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Benzocaine. Mifepristone may increase the QTc-prolonging activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Ethyl carbamate. Olanzapine can cause a decrease in the absorption of Ferric Carboxymaltose resulting in a reduced serum concentration and potentially a decrease in efficacy. Olanzapine can cause a decrease in the absorption of Dasatinib resulting in a reduced serum concentration and potentially a decrease in efficacy. The therapeutic efficacy of Tolazamide can be decreased when used in combination with Olanzapine. The serum concentration of Varenicline can be increased when it is combined with Olanzapine. The therapeutic efficacy of Troglitazone can be decreased when used in combination with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Vortioxetine. Olanzapine may increase the QTc-prolonging activities of Chloroquine. The serum concentration of Rilpivirine can be increased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Reserpine is combined with Olanzapine. The serum concentration of Nelfinavir can be decreased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Halothane. The risk or severity of adverse effects can be increased when Olanzapine is combined with Methoxyflurane. The risk or severity of adverse effects can be increased when Olanzapine is combined with Bupivacaine. Olanzapine may increase the central nervous system depressant (CNS depressant) activities of Azelastine. The serum concentration of Olanzapine can be decreased when it is combined with Ritonavir. Olanzapine may increase the QTc-prolonging activities of Escitalopram. The therapeutic efficacy of Deoxyspergualin can be decreased when used in combination with Olanzapine. The risk or severity of adverse effects can be increased when Triazolam is combined with Olanzapine. 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 Butabarbital is combined with Olanzapine. The therapeutic efficacy of Cysteamine can be decreased when used in combination with Olanzapine. Olanzapine may increase the QTc-prolonging activities of Lumefantrine. The risk or severity of adverse effects can be increased when Rufinamide is combined with Olanzapine. The serum concentration of Mevastatin can be increased when it is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Oxycodone. The risk or severity of adverse effects can be increased when Nicergoline is combined with Olanzapine. The metabolism of Olanzapine can be decreased when combined with Darifenacin. The therapeutic efficacy of Insulin Aspart can be decreased when used in combination with Olanzapine. The therapeutic efficacy of Liraglutide can be decreased when used in combination with Olanzapine. Olanzapine may decrease the stimulatory activities of Mephentermine. The serum concentration of Simvastatin can be increased when it is combined with Olanzapine. The therapeutic efficacy of Amantadine can be decreased when used in combination with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Cetirizine. 7,8-Dichloro-1,2,3,4-tetrahydroisoquinoline may increase the serotonergic activities of Olanzapine. The risk or severity of adverse effects can be increased when Phenelzine is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Meprobamate. The risk or severity of adverse effects can be increased when Olanzapine is combined with Pethidine. Magnesium Sulfate may increase the central nervous system depressant (CNS depressant) activities of Olanzapine. The risk or severity of adverse effects can be increased when Flumazenil is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Fencamfamine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Pipotiazine. Droperidol may increase the central nervous system depressant (CNS depressant) activities of Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Amobarbital. The serum concentration of Indinavir can be decreased when it is combined with Olanzapine. Olanzapine may increase the QTc-prolonging activities of Arsenic trioxide. The risk or severity of adverse effects can be increased when Acepromazine is combined with Olanzapine. The risk or severity of adverse effects can be increased when Moricizine is combined with Olanzapine. The risk or severity of adverse effects can be increased when Alimemazine is combined with Olanzapine. The risk or severity of adverse effects can be increased when Temazepam is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Entacapone. Mebanazine may increase the serotonergic activities of Olanzapine. The metabolism of Olanzapine can be decreased when combined with Stiripentol. The risk or severity of adverse effects can be increased when Olanzapine is combined with Piritramide. The risk or severity of adverse effects can be increased when Olanzapine is combined with Fluticasone propionate. The therapeutic efficacy of Insulin Human can be decreased when used in combination with Olanzapine. Olanzapine may increase the central nervous system depressant (CNS depressant) activities of Mirtazapine. Olanzapine may decrease the stimulatory activities of 4-Bromo-2,5-dimethoxyamphetamine. The risk or severity of adverse effects can be increased when Methysergide is combined with Olanzapine. 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 Propericiazine is combined with Olanzapine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Oxybuprocaine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Alfaxalone.