Use Caution/Monitor. Comment: Beta blockers (esp. non selective) antagonize theophylline effects, while at the same time increasing theophylline levels and toxicity (mechanism: decreased theophylline metabolism). Smoking increases risk of interaction.blinatumomabblinatumomab increases levels of theophylline by decreasing metabolism. Modify Therapy/Monitor Closely. Treatment initiation causes transient release of cytokines that may suppress CYP450 enzymes; highest drug-drug interaction risk is during the first 9 days of the first cycle and the first 2 days of the 2nd cycle in patients who are receiving concomitant CYP450 substrates, particularly those with a narrow therapeutic index.bosentanbosentan will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.brodalumabbrodalumab, theophylline. Other (see comment). Use Caution/Monitor. Comment: Formation of CYP450 enzymes can be altered by increased levels of certain cytokines during chronic inflammation; thus, brodalumab could normalize the formation of CYP450 enzymes. Upon initiation or discontinuation of brodalumab in patients who are receiving concomitant CYP450 substrates, particularly those with a narrow therapeutic index, consider monitoring for therapeutic effect.budesonidebudesonide will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.butabarbitalbutabarbital will decrease the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.butabarbital will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.butalbitalbutalbital will decrease the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.butalbital will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.cannabidiolcannabidiol, theophylline. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Owing to the potential for both CYP1A2 induction and inhibition with the coadministration of CYP1A2 substrates and cannabidiol, consider reducing dosage adjustment of CYP1A2 substrates as clinically appropriate.carbamazepinecarbamazepine will decrease the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.carvedilolcarvedilol, theophylline. Other (see comment). Use Caution/Monitor. Comment: Beta blockers (esp. non selective) antagonize theophylline effects, while at the same time increasing theophylline levels and toxicity (mechanism: decreased theophylline metabolism). Smoking increases risk of interaction.celiprololceliprolol, theophylline. Other (see comment). Use Caution/Monitor. Comment: Beta blockers (esp. non selective) antagonize theophylline effects, while at the same time increasing theophylline levels and toxicity (mechanism: decreased theophylline metabolism). Smoking increases risk of interaction.cenobamatecenobamate will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.cenobamate, theophylline. Either increases effects of the other by sedation. Use Caution/Monitor.cigarette smokingcigarette smoking will decrease the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.cimetidinecimetidine will increase the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.cobicistatcobicistat will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.conivaptanconivaptan will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.cortisonecortisone will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.crizotinibcrizotinib increases levels of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of crizotinib with CYP3A substrates with narrow therapeutic indices should be avoided.crofelemercrofelemer increases levels of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.dabrafenibdabrafenib will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.daridorexanttheophylline and daridorexant both increase sedation. Modify Therapy/Monitor Closely. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment. darifenacindarifenacin will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.darunavirdarunavir will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.dasatinibdasatinib will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.deferasiroxdeferasirox will increase the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Avoid the concomitant use of theophylline with deferasirox. If you must co-administer theophylline and deferasirox, monitor theophylline concentration and consider theophylline dose modification.deflazacorttheophylline and deflazacort both decrease serum potassium. Use Caution/Monitor.dexamethasonedexamethasone will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.DHEA, herbalDHEA, herbal will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.dichlorphenamidedichlorphenamide and theophylline both decrease serum potassium. Use Caution/Monitor.dichlorphenamide, theophylline. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Both drugs can cause metabolic acidosis.difelikefalindifelikefalin and theophylline both increase sedation. Use Caution/Monitor.diltiazemdiltiazem will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.doxapramdoxapram, theophylline. Mechanism: unspecified interaction mechanism. Use Caution/Monitor. Increased skeletal muscle activity, agitation, hyperactivity.dronedaronedronedarone will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.dulaglutidedulaglutide, theophylline. Other (see comment). Use Caution/Monitor. Comment: Dulaglutide slows gastric emptying and may impact absorption of concomitantly administered oral medications; be particularly cautious when coadministered with drugs that have a narrow therapeutic index.dupilumabdupilumab, theophylline. Other (see comment). Use Caution/Monitor. Comment: Formation of CYP450 enzymes can be altered by increased levels of certain cytokines during chronic inflammation; thus, dupilumab could normalize the formation of CYP450 enzymes. Upon initiation or discontinuation of dupilumab in patients who are receiving concomitant CYP450 substrates, particularly those with a narrow therapeutic index, consider monitoring for therapeutic effect.efavirenzefavirenz will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.elagolixelagolix decreases levels of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.elvitegravir/cobicistat/emtricitabine/tenofovir DFelvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.encorafenibencorafenib, theophylline. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.epcoritamabepcoritamab, theophylline. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Epcoritamab causes release of cytokines that may suppress activity of CYP enzymes, resulting in increased exposure of CYP substrates. For certain CYP substrates, minimal changes in their concentration may lead to serious adverse reactions. If needed, modify therapy as recommended in the substrate's prescribing information. .erythromycin baseerythromycin base will increase the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.erythromycin ethylsuccinateerythromycin ethylsuccinate will increase the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.erythromycin lactobionateerythromycin lactobionate will increase the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.erythromycin stearateerythromycin stearate will increase the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.eslicarbazepine acetateeslicarbazepine acetate will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.esmololesmolol, theophylline. Other (see comment). Use Caution/Monitor. Comment: Beta blockers (esp. non selective) antagonize theophylline effects, while at the same time increasing theophylline levels and toxicity (mechanism: decreased theophylline metabolism). Smoking increases risk of interaction.ethinylestradiolethinylestradiol will increase the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.etravirineetravirine will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fedratinibfedratinib will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.ferric maltolferric maltol, theophylline. Either increases levels of the other by unspecified interaction mechanism. Modify Therapy/Monitor Closely. Coadministration of ferric maltol with certain oral medications may decrease the bioavailability of either ferric maltol and some oral drugs. For oral drugs where reductions in bioavailability may cause clinically significant effects on its safety or efficacy, separate administration of ferric maltol from these drugs. Duration of separation may depend on the absorption of the medication concomitantly administered (eg, time to peak concentration, whether the drug is an immediate or extended release product).fexinidazolefexinidazole will increase the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.fluconazolefluconazole will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fludrocortisonefludrocortisone will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fosamprenavirfosamprenavir will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fosaprepitantfosaprepitant will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.fosphenytoinfosphenytoin will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.glofitamabglofitamab, theophylline. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Glofitamab causes release of cytokines that may suppress activity of CYP enzymes, resulting in increased exposure of CYP substrates. For certain CYP substrates, minimal changes in their concentration may lead to serious adverse reactions. If needed, modify therapy as recommended in the substrate's prescribing information. .grapefruitgrapefruit will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.green teagreen tea increases levels of theophylline by decreasing renal clearance. Use Caution/Monitor. Due to caffeine content.griseofulvingriseofulvin will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.guselkumabguselkumab, theophylline. Other (see comment). Use Caution/Monitor. Comment: Formation of CYP450 enzymes can be altered by increased levels of certain cytokines during chronic inflammation; thus, normalizing the formation of CYP450 enzymes. Upon initiation or discontinuation of guselkumab in patients who are receiving concomitant CYP450 substrates, particularly those with a narrow therapeutic index, consider monitoring for therapeutic effect.hydrocortisonehydrocortisone will decrease the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.iloperidoneiloperidone increases levels of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.indacaterol, inhaledtheophylline, indacaterol, inhaled. serum potassium. Use Caution/Monitor. Combination may increase risk of hypokalemia.indinavirindinavir will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.interferon alfa 2binterferon alfa 2b increases levels of theophylline by decreasing metabolism. Use Caution/Monitor. Greater risk of interaction in smokers.interferon alfa n3interferon alfa n3 increases levels of theophylline by decreasing metabolism. Use Caution/Monitor. Greater risk of interaction in smokers.interferon gamma 1binterferon gamma 1b increases levels of theophylline by decreasing metabolism. Use Caution/Monitor. Greater risk of interaction in smokers.iodine (radioactive)iodine (radioactive) increases levels of theophylline by decreasing elimination. Use Caution/Monitor.isoniazidisoniazid will increase the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.isoniazid will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.istradefyllineistradefylline will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.itraconazoleitraconazole will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.ixekizumabixekizumab, theophylline. Other (see comment). Use Caution/Monitor. Comment: Formation of CYP450 enzymes can be altered by increased levels of certain cytokines during chronic inflammation; thus, ixekizumab could normalize the formation of CYP450 enzymes. Upon initiation or discontinuation of ixekizumab in patients who are receiving concomitant CYP450 substrates, particularly those with a narrow therapeutic index, consider monitoring for therapeutic effect.labetalollabetalol, theophylline. Other (see comment). Use Caution/Monitor. Comment: Beta blockers (esp. non selective) antagonize theophylline effects, while at the same time increasing theophylline levels and toxicity (mechanism: decreased theophylline metabolism). Smoking increases risk of interaction.lapatiniblapatinib will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.lenacapavirlenacapavir will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.levonorgestrel oral/ethinylestradiol/ferrous bisglycinatelevonorgestrel oral/ethinylestradiol/ferrous bisglycinate will increase the level or effect of theophylline by decreasing metabolism. Use Caution/Monitor. Combined oral contraceptives containing EE may inhibit the metabolism and increase plasma concentrations of cyclosporine.lonapegsomatropinlonapegsomatropin will decrease the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Limited published data indicate that growth hormone treatment increases cytochrome P450 (CYP450)-mediated antipyrine clearance. Caution with sensitive CYP substrateslonapegsomatropin will decrease the level or effect