Alka seltzer plus severe cold and cough

albuterol and phenylephrine both decrease sedation. Use Caution/Monitor.albuterol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

alfentanil increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

alprazolam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

amitriptyline increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

amobarbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

amoxapine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

apalutamide will decrease the level or effect of acetaminophen by increasing elimination. Use Caution/Monitor. Apalutamide induces UGT and may decrease systemic exposure of drugs that are UGT substrates.

arformoterol and phenylephrine both decrease sedation. Use Caution/Monitor.arformoterol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

aripiprazole increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

armodafinil and phenylephrine both decrease sedation. Use Caution/Monitor.

acetaminophen will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

atomoxetine, phenylephrine. Other (see comment). Use Caution/Monitor. Comment: Due to the potential for increases in blood pressure and heart rate, atomoxetine should be used cautiously with vasopressors such as phenylephrine.

acetaminophen will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

acetaminophen increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

azelastine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

belladonna and opium increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

benperidol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

benzphetamine and phenylephrine both decrease sedation. Use Caution/Monitor.benzphetamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

bromocriptine, phenylephrine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Hypertension, V tach.

brompheniramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

acetaminophen, bupivacaine implant. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Local anesthetics may increase the risk of developing methemoglobinemia when concurrently exposed to drugs that also cause methemoglobinemia.

buprenorphine buccal increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

acetaminophen increases levels of busulfan by decreasing metabolism. Use Caution/Monitor. Use of acetaminophen prior to (< 72 hours) or concurrently with busulfan may result in decreased clearance of busulfan due to acetaminophen-induced decreases in glutathione levels.

butabarbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

butalbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

butorphanol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

caffeine and phenylephrine both decrease sedation. Use Caution/Monitor.

carbinoxamine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

chloral hydrate increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

chlordiazepoxide increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

chlorpheniramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

chlorpromazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.chlorpromazine, phenylephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

cinnarizine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

clemastine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

clomipramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

clonazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

clorazepate increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

clozapine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

codeine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

cyclizine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

cyproheptadine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

acetaminophen increases toxicity of dapsone topical by altering metabolism. Modify Therapy/Monitor Closely. May induce methemoglobinemia .

desipramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

dexchlorpheniramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

dexfenfluramine and phenylephrine both decrease sedation. Use Caution/Monitor.dexfenfluramine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

dexmedetomidine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

dexmethylphenidate and phenylephrine both decrease sedation. Use Caution/Monitor.dexmethylphenidate and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

dextroamphetamine and phenylephrine both decrease sedation. Use Caution/Monitor.dextroamphetamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

dextromoramide increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

diamorphine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

diethylpropion and phenylephrine both decrease sedation. Use Caution/Monitor.diethylpropion and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

difenoxin hcl increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

dimenhydrinate increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

diphenhydramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

diphenoxylate hcl increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

dipipanone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

dobutamine and phenylephrine both decrease sedation. Use Caution/Monitor.dobutamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

dopamine and phenylephrine both decrease sedation. Use Caution/Monitor.dopamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

dopexamine and phenylephrine both decrease sedation. Use Caution/Monitor.dopexamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

doxepin increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

droperidol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

phenylephrine and droxidopa both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. May increase risk for supine hypertension

eltrombopag increases levels of acetaminophen by decreasing metabolism. Use Caution/Monitor. UGT inhibition; significance of interaction unclear.

ephedrine and phenylephrine both decrease sedation. Use Caution/Monitor.ephedrine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.ephedrine, phenylephrine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor.

epinephrine and phenylephrine both decrease sedation. Use Caution/Monitor.epinephrine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

phenylephrine, epinephrine inhaled. Either increases effects of the other by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

epinephrine racemic and phenylephrine both decrease sedation. Use Caution/Monitor.epinephrine racemic and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

estazolam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

ethanol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

exenatide injectable solution will decrease the level or effect of acetaminophen by unspecified interaction mechanism. Use Caution/Monitor. To avoid potential interaction, give acetaminophen at least 1 hour before or 4 hours after exenatide injection.

exenatide injectable suspension will decrease the level or effect of acetaminophen by unspecified interaction mechanism. Use Caution/Monitor. To avoid potential interaction, give acetaminophen at least 1 hour before or 4 hours after exenatide injection.

fenfluramine and phenylephrine both decrease sedation. Use Caution/Monitor.fenfluramine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

acetaminophen will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or moderate CYP3A4 inhibitors. Adjust finererone dosage as needed.

acetaminophen will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased flibanserin adverse effects may occur if coadministered with multiple weak CYP3A4 inhibitors.

fluphenazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.fluphenazine, phenylephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

flurazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

formoterol and phenylephrine both decrease sedation. Use Caution/Monitor.formoterol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

haloperidol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

hydralazine, phenylephrine. Mechanism: pharmacodynamic antagonism. Use Caution/Monitor. Sympathomimetics can antagonize the activity of some antihypertensive agents.

hydromorphone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

hydroxyzine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

iloperidone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

imatinib decreases levels of acetaminophen by decreasing hepatic clearance. Modify Therapy/Monitor Closely. In vitro, imatinib was found to inhibit acetaminophen O-glucuronidation (Ki value of 58.5 micro-M) at therapeutic levels; avoid chronic acetaminophen therapy with imatinib; if occasional acetaminophen administered, do not exceed 1300 mg/day.

imipramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

phenylephrine increases effects of indacaterol, inhaled by Other (see comment). Use Caution/Monitor. Comment: If additional adrenergic drugs are to be administered by any route, they should be used with caution because the sympathetic effects of indacaterol may be potentiated.

phenylephrine decreases effects of insulin degludec by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. Sympathomimetics increase blood glucose by stimulating alpha and beta receptors; this action results in increased hepatic glucose production, glycogenolysis, and decreased insulin secretion.

phenylephrine decreases effects of insulin degludec/insulin aspart by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. Sympathomimetics increase blood glucose by stimulating alpha and beta receptors; this action results in increased hepatic glucose production, glycogenolysis, and decreased insulin secretion.

phenylephrine decreases effects of insulin inhaled by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. Sympathomimetics increase blood glucose by stimulating alpha and beta receptors; this action results in increased hepatic glucose production, glycogenolysis, and decreased insulin secretion.

acetaminophen will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

isoniazid will increase the level or effect of acetaminophen by affecting hepatic enzyme CYP2E1 metabolism. Use Caution/Monitor.

isoproterenol and phenylephrine both decrease sedation. Use Caution/Monitor.isoproterenol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

acetaminophen increases levels of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor when coadministered with weak CYP3A4 inhibitors .

ketotifen, ophthalmic increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

acetaminophen will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification.

levalbuterol and phenylephrine both decrease sedation. Use Caution/Monitor.levalbuterol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

levonorgestrel oral/ethinylestradiol/ferrous bisglycinate will decrease the level or effect of acetaminophen by unknown mechanism. Use Caution/Monitor.acetaminophen increases levels of levonorgestrel oral/ethinylestradiol/ferrous bisglycinate by decreasing hepatic clearance. Use Caution/Monitor. Coadministration of ascorbic acid and certain combined hormonal contraceptives (CHCs) containing EE may increase plasma EE concentrations, possibly by inhibition of conjugation.

levorphanol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

lisdexamfetamine and phenylephrine both decrease sedation. Use Caution/Monitor.lisdexamfetamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

lixisenatide will decrease the level or effect of acetaminophen by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. GLP1 agonists delay gastric emptying, which may affect absorption of concomitantly administered oral medications. No effects on acetaminophen Cmax and Tmax were observed when acetaminophen was administered 1 hr before lixisenatide. When administered 1 or 4 hr after lixisenatide, acetaminophen Cmax was decreased by 29% and 31% respectively and median Tmax was delayed by 2 and 1.75 hr, respectively.

lofepramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

lofexidine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

acetaminophen increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.

loprazolam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

lorazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

lormetazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

loxapine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

loxapine inhaled increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

maprotiline increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

marijuana increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

melatonin increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

meperidine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

meprobamate increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

metaproterenol and phenylephrine both decrease sedation. Use Caution/Monitor.metaproterenol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

methadone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

methamphetamine and phenylephrine both decrease sedation. Use Caution/Monitor.methamphetamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

methyldopa increases effects of phenylephrine by unknown mechanism. Use Caution/Monitor.

methylenedioxymethamphetamine and phenylephrine both decrease sedation. Use Caution/Monitor.methylenedioxymethamphetamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

midazolam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

acetaminophen will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of mild CYP3A4 inhibitors with midazolam intranasal may cause higher midazolam systemic exposure, which may prolong sedation.

midodrine and phenylephrine both decrease sedation. Use Caution/Monitor.midodrine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

mipomersen, acetaminophen. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Both drugs have potential to increase hepatic enzymes; monitor LFTs.

mirtazapine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

modafinil and phenylephrine both decrease sedation. Use Caution/Monitor.

morphine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

motherwort increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

moxonidine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

nabilone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

nadolol increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode (rare).

nalbuphine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

norepinephrine and phenylephrine both decrease sedation. Use Caution/Monitor.norepinephrine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

nortriptyline increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

olanzapine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

phenylephrine 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 effects

opium tincture increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

oxazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

oxycodone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

oxymetazoline topical and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

oxymorphone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

oxytocin increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor.

paliperidone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

papaveretum increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

pentazocine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

pentobarbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

perphenazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.perphenazine, phenylephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

phendimetrazine and phenylephrine both decrease sedation. Use Caution/Monitor.phendimetrazine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

phenobarbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

phentermine and phenylephrine both decrease sedation. Use Caution/Monitor.phentermine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

pholcodine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

pimozide increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

pindolol increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode (rare).

pirbuterol and phenylephrine both decrease sedation. Use Caution/Monitor.pirbuterol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

primidone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

prochlorperazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.prochlorperazine, phenylephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

promazine, phenylephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

promethazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.promethazine, phenylephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

propofol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

propranolol increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode (rare).

phenylephrine and propylhexedrine both decrease sedation. Use Caution/Monitor.phenylephrine and propylhexedrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

protriptyline increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

phenylephrine and pseudoephedrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

quazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

quetiapine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

rasagiline increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode.

risperidone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

phenylephrine and safinamide both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. Monitor patients for hypertension if safinamide is prescribed concomitantly with prescription or nonprescription sympathomimetics, including nasal, oral, or ophthalmic decongestants and cold remedies.

salmeterol and phenylephrine both decrease sedation. Use Caution/Monitor.salmeterol and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

scullcap increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

secobarbital increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

selegiline increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode.

serdexmethylphenidate/dexmethylphenidate and phenylephrine both decrease sedation. Use Caution/Monitor.serdexmethylphenidate/dexmethylphenidate and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

shepherd's purse increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

phenylephrine and solriamfetol both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

sufentanil increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

tapentadol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

acetaminophen will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

temazepam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

terbutaline and phenylephrine both decrease sedation. Use Caution/Monitor.terbutaline and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

tetracaine, acetaminophen. Other (see comment). Use Caution/Monitor. Comment: Monitor for signs of methemoglobinemia when methemoglobin-inducing drugs are coadministered.

thioridazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.thioridazine, phenylephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

thiothixene increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

timolol increases effects of phenylephrine by pharmacodynamic synergism. Use Caution/Monitor. Risk of acute hypertensive episode (rare).

acetaminophen will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

topiramate increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.

tramadol increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

trazodone increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

triazolam increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

triclofos increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

trifluoperazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.trifluoperazine, phenylephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

trimipramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

triprolidine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

acetaminophen increases effects of warfarin by anticoagulation. Use Caution/Monitor.

phenylephrine and xylometazoline both decrease sedation. Use Caution/Monitor.phenylephrine and xylometazoline both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.

acetazolamide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

albiglutide decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.

alfuzosin, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.

acetaminophen increases effects of antithrombin alfa by unknown mechanism. Minor/Significance Unknown.

acetaminophen increases effects of antithrombin III by unknown mechanism. Minor/Significance Unknown.

acetaminophen increases effects of argatroban by unknown mechanism. Minor/Significance Unknown.

asenapine, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.

acetaminophen increases effects of bemiparin by unknown mechanism. Minor/Significance Unknown.

acetaminophen increases effects of bivalirudin by unknown mechanism. Minor/Significance Unknown.

carbamazepine decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

cholestyramine decreases levels of acetaminophen by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

clonazepam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

colestipol decreases levels of acetaminophen by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

acetaminophen increases effects of dalteparin by unknown mechanism. Minor/Significance Unknown.

desmopressin increases effects of phenylephrine by pharmacodynamic synergism. Minor/Significance Unknown.

diazepam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

disulfiram will increase the level or effect of acetaminophen by affecting hepatic enzyme CYP2E1 metabolism. Minor/Significance Unknown.

doxazosin, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.

acetaminophen increases effects of enoxaparin by unknown mechanism. Minor/Significance Unknown.

ethanol will decrease the level or effect of acetaminophen by affecting hepatic enzyme CYP2E1 metabolism. Minor/Significance Unknown.ethanol increases toxicity of acetaminophen by decreasing metabolism. Minor/Significance Unknown.

ethosuximide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

eucalyptus increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Minor/Significance Unknown.

felbamate decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

acetaminophen increases effects of fondaparinux by unknown mechanism. Minor/Significance Unknown.

fosphenytoin decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

green tea increases effects of acetaminophen by pharmacodynamic synergism. Minor/Significance Unknown. (Theoretical, due to caffeine content).

acetaminophen increases effects of heparin by unknown mechanism. Minor/Significance Unknown.

isoniazid increases toxicity of acetaminophen by unknown mechanism. Minor/Significance Unknown.

lacosamide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

lamotrigine decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

levetiracetam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

liraglutide decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.

lorazepam decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

methsuximide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

metoclopramide increases levels of acetaminophen by enhancing GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

metronidazole will increase the level or effect of acetaminophen by affecting hepatic enzyme CYP2E1 metabolism. Minor/Significance Unknown.

moxisylyte, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.

oxcarbazepine decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

oxybutynin decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.

oxybutynin topical decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.

oxybutynin transdermal decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.

acetaminophen increases effects of phenindione by unknown mechanism. Minor/Significance Unknown.

phenobarbital decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

phenoxybenzamine, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.

phentolamine, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.

phenytoin decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

prazosin, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.

primidone decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

acetaminophen increases effects of protamine by unknown mechanism. Minor/Significance Unknown.

rifabutin decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

rifampin decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

rufinamide decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.

acetaminophen will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

acetaminophen will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

sage increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Minor/Significance Unknown.

silodosin, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.

terazosin, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.

tiagabine decreases levels of acetaminophen by increasing metabolism. Minor/Significance Unknown. Enhanced metabolism incr levels of hepatotoxic metabolites.