pressure and heart rate. Use Caution/Monitor.fenoprofenfenoprofen increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.fesoterodinefesoterodine and glycopyrrolate inhaled both decrease cholinergic effects/transmission. Use Caution/Monitor.fingolimodfingolimod and formoterol both increase QTc interval. Use Caution/Monitor.flavoxateflavoxate and glycopyrrolate inhaled both decrease cholinergic effects/transmission. Use Caution/Monitor.flecainideflecainide and formoterol both increase QTc interval. Modify Therapy/Monitor Closely.fluoxetinefluoxetine and formoterol both increase QTc interval. Modify Therapy/Monitor Closely. Fluoxetine prolongs the QT interval; the prescribing information for fluoxetine recommends avoiding concurrent use of other drugs that may prolong the QT interval; risk may be increased with higher doses and/or when associated with hypokalemia; drugs that prolong the QTc interval may potentiate the effects of beta2 agonists on the cardiovascular systemfluphenazinefluphenazine increases toxicity of glycopyrrolate inhaled by unknown mechanism. Use Caution/Monitor.fluphenazine increases effects of glycopyrrolate inhaled by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.glycopyrrolate inhaled decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor.glycopyrrolate inhaled decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.fluphenazine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.flurazepamflurazepam increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.galantaminegalantamine increases and glycopyrrolate inhaled decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.flurbiprofenflurbiprofen increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.fluvoxaminefluvoxamine and formoterol both increase QTc interval. Modify Therapy/Monitor Closely.foscarnetformoterol and foscarnet both increase QTc interval. Modify Therapy/Monitor Closely.fostemsavirformoterol and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir. furosemideformoterol and furosemide both decrease serum potassium. Use Caution/Monitor.gemifloxacingemifloxacin and formoterol both increase QTc interval. Use Caution/Monitor.gentamicinformoterol and gentamicin both decrease serum potassium. Use Caution/Monitor.gilteritinibgilteritinib and formoterol both increase QTc interval. Use Caution/Monitor.glycopyrronium tosylate topicalglycopyrronium tosylate topical, glycopyrrolate inhaled. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration of glycopyrronium tosylate topical with other anticholinergic medications may result in additive anticholinergic adverse effects.goserelingoserelin increases toxicity of formoterol by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.haloperidolhaloperidol increases effects of glycopyrrolate inhaled by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.glycopyrrolate inhaled decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor.glycopyrrolate inhaled decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.haloperidol increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.henbaneglycopyrrolate inhaled and henbane both decrease cholinergic effects/transmission. Use Caution/Monitor.histrelinhistrelin increases toxicity of formoterol by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.homatropineglycopyrrolate inhaled and homatropine both decrease cholinergic effects/transmission. Use Caution/Monitor.huperzine Ahuperzine A increases and glycopyrrolate inhaled decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.hydrochlorothiazideformoterol and hydrochlorothiazide both decrease serum potassium. Use Caution/Monitor.hydromorphonehydromorphone increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.hydroxyzinehydroxyzine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.hyoscyamineglycopyrrolate inhaled and hyoscyamine both decrease cholinergic effects/transmission. Use Caution/Monitor.hyoscyamine sprayglycopyrrolate inhaled and hyoscyamine spray both decrease cholinergic effects/transmission. Use Caution/Monitor.ibuprofenibuprofen increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.ibuprofen IVibuprofen IV increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.iloperidoneglycopyrrolate inhaled decreases levels of iloperidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.iloperidone increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.glycopyrrolate inhaled decreases levels of iloperidone by pharmacodynamic antagonism. Use Caution/Monitor.iloperidone increases effects of glycopyrrolate inhaled by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.formoterol and iloperidone both increase QTc interval. Modify Therapy/Monitor Closely.imipramineglycopyrrolate inhaled and imipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.imipramine increases levels of glycopyrrolate inhaled by unknown mechanism. Use Caution/Monitor.imipramine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.indapamideformoterol and indapamide both decrease serum potassium. Use Caution/Monitor.ipratropiumglycopyrrolate inhaled and ipratropium both decrease cholinergic effects/transmission. Use Caution/Monitor.indomethacinindomethacin increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.isoproterenolformoterol and isoproterenol both decrease serum potassium. Use Caution/Monitor.formoterol and isoproterenol both decrease sedation. Use Caution/Monitor.formoterol and isoproterenol both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.itraconazoleitraconazole and formoterol both increase QTc interval. Use Caution/Monitor.ketoprofenketoprofen increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.ketorolacketorolac increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.ketorolac intranasalketorolac intranasal increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. .ketotifen, ophthalmicketotifen, ophthalmic increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.labetalollabetalol increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.labetalol decreases effects of formoterol by pharmacodynamic antagonism. Use Caution/Monitor.lapatinibformoterol and lapatinib both increase QTc interval. Modify Therapy/Monitor Closely.lenvatinibformoterol and lenvatinib both increase QTc interval. Use Caution/Monitor. Lenvatinib prescribing information recommends monitoring ECG closely when coadministered with QT prolonging drugs.leuprolideleuprolide increases toxicity of formoterol by QTc interval. Use Caution/Monitor. Increases risk of torsades de pointes.levalbuterolformoterol and levalbuterol both decrease serum potassium. Use Caution/Monitor.formoterol and levalbuterol both decrease sedation. Use Caution/Monitor.formoterol and levalbuterol both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.levodopaglycopyrrolate inhaled, levodopa. Other (see comment). Use Caution/Monitor. Comment: Anticholinergic agents may enhance the therapeutic effects of levodopa; however, anticholinergic agents can exacerbate tardive dyskinesia. In high dosage, anticholinergics may decrease the effects of levodopa by delaying its GI absorption. .levofloxacinformoterol and levofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.levorphanollevorphanol increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.lisdexamfetamineformoterol and lisdexamfetamine both decrease sedation. Use Caution/Monitor.formoterol and lisdexamfetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.lofepramineglycopyrrolate inhaled and lofepramine both decrease cholinergic effects/transmission. Use Caution/Monitor.lofepramine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.lofexidinelofexidine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.loxapineglycopyrrolate inhaled decreases levels of loxapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.glycopyrrolate inhaled decreases levels of loxapine by pharmacodynamic antagonism. Use Caution/Monitor.loxapine increases effects of glycopyrrolate inhaled by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.loprazolamloprazolam increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.lorazepamlorazepam increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.lormetazepamlormetazepam increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.lornoxicamlornoxicam increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.loxapineloxapine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.loxapine inhaledglycopyrrolate inhaled decreases levels of loxapine inhaled by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.glycopyrrolate inhaled decreases levels of loxapine inhaled by pharmacodynamic antagonism. Use Caution/Monitor.loxapine inhaled increases effects of glycopyrrolate inhaled by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.loxapine inhaled increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.maprotilineglycopyrrolate inhaled and maprotiline both decrease cholinergic effects/transmission. Use Caution/Monitor.maprotiline increases levels of glycopyrrolate inhaled by unknown mechanism. Use Caution/Monitor.maprotiline increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.marijuanamarijuana increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.meclizineglycopyrrolate inhaled and meclizine both decrease cholinergic effects/transmission. Use Caution/Monitor.meclofenamatemeclofenamate increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.mefenamic acidmefenamic acid increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.melatoninmelatonin increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.meloxicammeloxicam increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.meperidinemeperidine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.meprobamatemeprobamate increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.metaproterenolformoterol and metaproterenol both decrease serum potassium. Use Caution/Monitor.formoterol and metaproterenol both decrease sedation. Use Caution/Monitor.formoterol and metaproterenol both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.methadoneformoterol and methadone both increase QTc interval. Modify Therapy/Monitor Closely.methadone increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.methamphetamineformoterol and methamphetamine both decrease sedation. Use Caution/Monitor.formoterol and methamphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.methscopolamineglycopyrrolate inhaled and methscopolamine both decrease cholinergic effects/transmission. Use Caution/Monitor.methyclothiazideformoterol and methyclothiazide both decrease serum potassium. Use Caution/Monitor.methylenedioxymethamphetamineformoterol and methylenedioxymethamphetamine both decrease sedation. Use Caution/Monitor.formoterol and methylenedioxymethamphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.methylphenidateformoterol and methylphenidate both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.metolazoneformoterol and metolazone both decrease serum potassium. Use Caution/Monitor.metoprololmetoprolol increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.metoprolol decreases effects of formoterol by pharmacodynamic antagonism. Use Caution/Monitor.midazolammidazolam increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.midodrineformoterol and midodrine both decrease sedation. Use Caution/Monitor.formoterol and midodrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.mifepristonemifepristone, formoterol. QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.mirtazapinemirtazapine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.modafinilformoterol and modafinil both decrease sedation. Use Caution/Monitor.morphinemorphine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.motherwortmotherwort increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.moxonidinemoxonidine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.nabilonenabilone increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.nabumetonenabumetone increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.nadololnadolol increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.nadolol decreases effects of formoterol by pharmacodynamic antagonism. Use Caution/Monitor.nalbuphinenalbuphine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.naproxennaproxen increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.nebivololnebivolol increases and formoterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.nebivolol decreases effects of formoterol by pharmacodynamic antagonism. Use Caution/Monitor.neostigmineneostigmine increases and glycopyrrolate inhaled decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.norepinephrineformoterol and norepinephrine both decrease serum potassium. Use Caution/Monitor.formoterol and norepinephrine both decrease sedation. Use Caution/Monitor.formoterol and norepinephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.nortriptylineglycopyrrolate inhaled and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.nortriptyline increases levels of glycopyrrolate inhaled by unknown mechanism. Use Caution/Monitor.nortriptyline increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.ofloxacinformoterol and ofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.olanzapineglycopyrrolate inhaled decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.glycopyrrolate inhaled decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.olanzapine increases effects of glycopyrrolate inhaled by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.olanzapineolanzapine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.olodaterol inhaledformoterol and olodaterol inhaled both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. Caution with coadministration of adrenergic drugs by any route because of additive sympathetic effectsonabotulinumtoxinAonabotulinumtoxinA and glycopyrrolate inhaled both decrease cholinergic effects/transmission. Use Caution/Monitor.opium tinctureopium tincture increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.orphenadrineglycopyrrolate inhaled and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.osilodrostatosilodrostat and formoterol both increase QTc interval. Use Caution/Monitor.osimertinibosimertinib and formoterol both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.oxaliplatinoxaliplatin will increase the level or effect of formoterol by Other (see comment). Use Caution/Monitor. Monitor for ECG changes if therapy is initiated in patients with drugs known to prolong QT interval.oxaprozinoxaprozin increases and formoterol decreases serum potassium.