The metabolism of Theophylline can be decreased when combined with Interferon Alfa-2b, Recombinant. The serum concentration of Theophylline can be decreased when it is combined with Letaxaban. The metabolism of Mirtazapine can be decreased when combined with Theophylline. The metabolism of Theophylline can be decreased when combined with Etravirine. The therapeutic efficacy of Quazepam can be decreased when used in combination with Theophylline. The risk or severity of adverse effects can be increased when Theophylline is combined with Indacaterol. Timolol may decrease the bronchodilatory activities of Theophylline. The serum concentration of Theophylline can be increased when it is combined with Abiraterone. The risk or severity of adverse effects can be increased when Theophylline is combined with Pancuronium. The serum concentration of Theophylline can be increased when it is combined with Propylthiouracil. The therapeutic efficacy of Flurazepam can be decreased when used in combination with Theophylline. The metabolism of Cilostazol can be decreased when combined with Theophylline. The metabolism of Deutetrabenazine can be decreased when combined with Theophylline. The therapeutic efficacy of Estazolam can be decreased when used in combination with Theophylline. The serum concentration of Theophylline can be decreased when it is combined with Aprotinin. The serum concentration of Theophylline can be decreased when it is combined with 3,4-Dichloroisocoumarin. The metabolism of Theophylline can be decreased when combined with Indinavir. The metabolism of Palonosetron can be decreased when combined with Theophylline. The metabolism of Azelastine can be decreased when combined with Theophylline. The metabolism of Acetaminophen can be decreased when combined with Theophylline. The metabolism of Theophylline can be decreased when combined with Lapatinib. The metabolism of Theophylline can be decreased when combined with Cinacalcet. The serum concentration of Theophylline can be increased when it is combined with Palbociclib. The metabolism of Theophylline can be decreased when combined with Thioridazine. The metabolism of Carmustine can be decreased when combined with Theophylline. The metabolism of Chlorpromazine can be decreased when combined with Theophylline. The metabolism of Theophylline can be increased when combined with Primidone. The therapeutic efficacy of CE-326597 can be decreased when used in combination with Theophylline. The metabolism of Imipramine can be decreased when combined with Theophylline. The metabolism of Albendazole can be decreased when combined with Theophylline. The serum concentration of Theophylline can be increased when it is combined with Quinine. The metabolism of Melatonin can be decreased when combined with Theophylline. The serum concentration of Theophylline can be decreased when it is combined with Zofenopril. The metabolism of Theophylline can be decreased when combined with Pioglitazone. The metabolism of Lumiracoxib can be decreased when combined with Theophylline. The metabolism of Iloperidone can be decreased when combined with Theophylline. The metabolism of Theophylline can be decreased when combined with Albinterferon Alfa-2B. The metabolism of Theophylline can be decreased when combined with Nefazodone. The metabolism of Clopidogrel can be decreased when combined with Theophylline. The serum concentration of Theophylline can be decreased when it is combined with Benazepril. The therapeutic efficacy of Prazepam can be decreased when used in combination with Theophylline. The serum concentration of Theophylline can be increased when it is combined with Diethylstilbestrol. The metabolism of Theophylline can be decreased when combined with Kitasamycin. The serum concentration of Theophylline can be increased when it is combined with Probenecid. The serum concentration of Theophylline can be decreased when it is combined with Amobarbital. The metabolism of Theophylline can be decreased when combined with Telithromycin. The metabolism of Desipramine can be decreased when combined with Theophylline. The metabolism of Theophylline can be decreased when combined with Lobeglitazone. The serum concentration of Theophylline can be decreased when it is combined with Perindopril. The therapeutic efficacy of Clorazepate can be decreased when used in combination with Theophylline. Carteolol may decrease the bronchodilatory activities of Theophylline. The metabolism of Theophylline can be decreased when combined with Thiabendazole. The metabolism of Clozapine can be decreased when combined with Theophylline. The metabolism of Pomalidomide can be decreased when combined with Theophylline. The metabolism of Clonidine can be decreased when combined with Theophylline. The therapeutic efficacy of Flumazenil can be decreased when used in combination with Theophylline. The metabolism of Theophylline can be decreased when combined with Methotrimeprazine. The therapeutic efficacy of Netazepide can be decreased when used in combination with Theophylline. The metabolism of Theophylline can be decreased when combined with Peginterferon alfa-2a. The serum concentration of Theophylline can be increased when it is combined with Methimazole. The therapeutic efficacy of Theophylline can be decreased when used in combination with Sarilumab. The metabolism of Diphenhydramine can be decreased when combined with Theophylline. The metabolism of Clenbuterol can be decreased when combined with Theophylline. The risk or severity of adverse effects can be increased when Theophylline is combined with Formoterol. The therapeutic efficacy of Adenosine can be decreased when used in combination with Theophylline. The therapeutic efficacy of Midazolam can be decreased when used in combination with Theophylline. The metabolism of Dapagliflozin can be decreased when combined with Theophylline. The metabolism of Theophylline can be increased when combined with Levothyroxine. The metabolism of Dacarbazine can be decreased when combined with Theophylline. The therapeutic efficacy of PF-477736 can be decreased when used in combination with Theophylline. The therapeutic efficacy of Triazolam can be decreased when used in combination with Theophylline. The serum concentration of Theophylline can be decreased when it is combined with Methohexital. The metabolism of Theophylline can be decreased when combined with Isradipine. The metabolism of Methoxyflurane can be decreased when combined with Theophylline. The metabolism of Theophylline can be increased when combined with Pentobarbital. The metabolism of Theophylline can be increased when combined with Liotrix. The metabolism of Duloxetine can be decreased when combined with Theophylline. The serum concentration of Theophylline can be decreased when it is combined with Bosentan. The metabolism of Theophylline can be increased when combined with Thyroid, porcine. The metabolism of Oxaliplatin can be decreased when combined with Theophylline. The metabolism of Mephenytoin can be decreased when combined with Theophylline. The serum concentration of Theophylline can be decreased when it is combined with Ximelagatran. The serum concentration of Theophylline can be decreased when it is combined with Tocilizumab. Celiprolol may decrease the bronchodilatory activities of Theophylline. The metabolism of Theophylline can be decreased when combined with Felodipine. The serum concentration of Theophylline can be increased when it is combined with Secoisolariciresinol. The metabolism of Tamoxifen can be decreased when combined with Theophylline. The metabolism of Enasidenib can be decreased when combined with Theophylline. The serum concentration of Theophylline can be decreased when it is combined with Epigallocatechin Gallate. The serum concentration of Theophylline can be increased when it is combined with Fosaprepitant. The metabolism of Theophylline can be decreased when combined with Imatinib. The metabolism of Antipyrine can be decreased when combined with Theophylline. The metabolism of Theophylline can be decreased when combined with Boceprevir. The metabolism of Levobupivacaine can be decreased when combined with Theophylline. The therapeutic efficacy of Oxazepam can be decreased when used in combination with Theophylline. The metabolism of Theophylline can be decreased when combined with Tipranavir. The metabolism of Theophylline can be decreased when combined with Dosulepin. The metabolism of Theophylline can be decreased when combined with Bupropion. The metabolism of Theophylline can be decreased when combined with Mexiletine. The serum concentration of Theophylline can be increased when it is combined with Fusidic Acid. Acebutolol may decrease the bronchodilatory activities of Theophylline. The metabolism of Theophylline can be decreased when combined with Crisaborole. The serum concentration of Theophylline can be decreased when it is combined with Remikiren. The metabolism of Bupivacaine can be decreased when combined with Theophylline. The metabolism of Theophylline can be increased when combined with Rifampicin. The metabolism of Theophylline can be decreased when combined with Peginterferon beta-1a. The metabolism of Dexfenfluramine can be decreased when combined with Theophylline. The metabolism of Ixazomib can be decreased when combined with Theophylline. The serum concentration of the active metabolites of Theophylline can be increased when Theophylline is used in combination with Febuxostat. The metabolism of Theophylline can be decreased when combined with Clemastine. The serum concentration of Theophylline can be decreased when it is combined with GM6001. The metabolism of Theophylline can be decreased when combined with Tolbutamide. The metabolism of Flunarizine can be decreased when combined with Theophylline. The therapeutic efficacy of Flunitrazepam can be decreased when used in combination with Theophylline. The serum concentration of Theophylline can be decreased when it is combined with Barbexaclone. The metabolism of Theophylline can be decreased when combined with Fluvastatin. The serum concentration of Theophylline can be decreased when it is combined with Temocapril. The metabolism of Theophylline can be increased when combined with Rifapentine. The serum concentration of Theophylline can be increased when it is combined with Osimertinib. The metabolism of Theophylline can be decreased when combined with Topiroxostat. The metabolism of Promazine can be decreased when combined with Theophylline. The serum concentration of Theophylline can be increased when it is combined with Deferasirox. The metabolism of Proguanil can be decreased when combined with Theophylline. Nebivolol may decrease the bronchodilatory activities of Theophylline. The serum concentration of Theophylline can be increased when it is combined with Cobicistat. The metabolism of Theophylline can be decreased when combined with Mirabegron. The serum concentration of Theophylline can be decreased when it is combined with Thiamylal. The serum concentration of Theophylline can be increased when it is combined with Zileuton. The metabolism of Theophylline can be decreased when combined with Eliglustat. The serum concentration of Theophylline can be decreased when it is combined with Isoprenaline.