of both agents. Use Caution/Monitor. diphenhydramine decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor. perphenazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. diphenhydramine and perphenazine both increase sedation. Use Caution/Monitor.Minor (1)diphenhydramine will increase the level or effect of perphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.pexidartinibSerious - Use Alternative (1)ibuprofen and pexidartinib both increase Other (see comment). Avoid or Use Alternate Drug. Pexidartinib can cause hepatotoxicity. Avoid coadministration of pexidartinib with other products know to cause hepatoxicity.phendimetrazineMonitor Closely (1)diphenhydramine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.phenelzineMonitor Closely (1)phenelzine increases effects of diphenhydramine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Coadministration of phenelzine and antihistamines may result in additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .phenindioneMonitor Closely (1)phenindione and ibuprofen both increase anticoagulation. Modify Therapy/Monitor Closely.phenobarbitalMonitor Closely (1)diphenhydramine and phenobarbital both increase sedation. Use Caution/Monitor.Minor (1)phenobarbital will decrease the level or effect of ibuprofen by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.phenoxybenzamineMonitor Closely (1)ibuprofen decreases effects of phenoxybenzamine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.phentermineMonitor Closely (1)diphenhydramine increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.phentolamineMonitor Closely (1)ibuprofen decreases effects of phentolamine by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.phenylephrineMonitor Closely (1)diphenhydramine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.phenylephrine POMonitor Closely (1)diphenhydramine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .pholcodineMonitor Closely (1)diphenhydramine and pholcodine both increase sedation. Use Caution/Monitor.physostigmineMonitor Closely (1)physostigmine increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.phytoestrogensMonitor Closely (1)ibuprofen and phytoestrogens both increase anticoagulation. Use Caution/Monitor.pilocarpineMonitor Closely (1)pilocarpine increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.pimozideMonitor Closely (4)diphenhydramine decreases levels of pimozide by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. diphenhydramine decreases levels of pimozide by pharmacodynamic antagonism. Use Caution/Monitor. pimozide increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. diphenhydramine and pimozide both increase sedation. Use Caution/Monitor.pindololMonitor Closely (2)ibuprofen decreases effects of pindolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. pindolol and ibuprofen both increase serum potassium. Use Caution/Monitor.pirbuterolMonitor Closely (2)ibuprofen increases and pirbuterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor. diphenhydramine increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.piroxicamMonitor Closely (2)ibuprofen and piroxicam both increase anticoagulation. Use Caution/Monitor. ibuprofen and piroxicam both increase serum potassium. Use Caution/Monitor.Minor (1)ibuprofen will increase the level or effect of piroxicam by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.pitolisantSerious - Use Alternative (1)diphenhydramine decreases effects of pitolisant by Other (see comment). Avoid or Use Alternate Drug. Comment: Pitolisant increases histamine levels in the brain; therefore, H1 receptor antagonists that cross the blood-brain barrier may reduce the efficacy of pitolisant.pivmecillinamMonitor Closely (2)pivmecillinam, ibuprofen. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor. pivmecillinam, ibuprofen. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.potassium acid phosphateMonitor Closely (1)ibuprofen and potassium acid phosphate both increase serum potassium. Modify Therapy/Monitor Closely.potassium chlorideMonitor Closely (1)ibuprofen and potassium chloride both increase serum potassium. Modify Therapy/Monitor Closely.potassium citrateMonitor Closely (1)ibuprofen and potassium citrate both increase serum potassium. Modify Therapy/Monitor Closely.potassium iodideMonitor Closely (1)potassium iodide and ibuprofen both increase serum potassium. Use Caution/Monitor.pralatrexateMonitor Closely (1)ibuprofen increases levels of pralatrexate by decreasing renal clearance. Use Caution/Monitor. NSAIDs may delay pralatrexate clearance, increasing drug exposure. Adjust the pralatrexate dose as needed.pralidoximeMonitor Closely (1)diphenhydramine and pralidoxime both decrease cholinergic effects/transmission. Use Caution/Monitor.pramlintideSerious - Use Alternative (1)pramlintide, diphenhydramine. Either increases effects of the other by pharmacodynamic synergism. Contraindicated. Synergistic inhibition of GI motility.prasugrelMonitor Closely (1)ibuprofen, prasugrel. Either increases effects of the other by anticoagulation. Use Caution/Monitor. Chronic use of NSAIDs with prasugrel may increase bleeding risk.prazosinMonitor Closely (1)ibuprofen decreases effects of prazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.prednisoloneMonitor Closely (1)ibuprofen, prednisolone. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of GI ulceration.prednisoneMonitor Closely (1)ibuprofen, prednisone. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of GI ulceration.pregabalinMonitor Closely (1)pregabalin, diphenhydramine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.pretomanidSerious - Use Alternative (1)ibuprofen, pretomanid. Either increases toxicity of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Pretomanid regimen associated with hepatotoxicity. Avoid alcohol and hepatotoxic agents, including herbal supplements and drugs other than bedaquiline and linezolid.primidoneMonitor Closely (1)diphenhydramine and primidone both increase sedation. Use Caution/Monitor.Minor (1)primidone will decrease the level or effect of ibuprofen by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.probenecidMonitor Closely (1)ibuprofen will increase the level or effect of probenecid by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.prochlorperazineMonitor Closely (4)diphenhydramine decreases levels of prochlorperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. diphenhydramine decreases levels of prochlorperazine by pharmacodynamic antagonism. Use Caution/Monitor. prochlorperazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. diphenhydramine and prochlorperazine both increase sedation. Use Caution/Monitor.Minor (1)diphenhydramine will increase the level or effect of prochlorperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.promazineMinor (1)diphenhydramine will increase the level or effect of promazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.promethazineMonitor Closely (4)diphenhydramine decreases levels of promethazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. diphenhydramine decreases levels of promethazine by pharmacodynamic antagonism. Use Caution/Monitor. promethazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. diphenhydramine and promethazine both increase sedation. Use Caution/Monitor.Minor (1)diphenhydramine will increase the level or effect of promethazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.propafenoneMonitor Closely (1)diphenhydramine will increase the level or effect of propafenone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.propanthelineMonitor Closely (1)diphenhydramine and propantheline both decrease cholinergic effects/transmission. Use Caution/Monitor.propofolMonitor Closely (1)propofol and diphenhydramine both increase sedation. Use Caution/Monitor.propranololMonitor Closely (3)propranolol and ibuprofen both increase serum potassium. Use Caution/Monitor. ibuprofen decreases effects of propranolol by pharmacodynamic antagonism. Use Caution/Monitor. Long term (>1 wk) NSAID use. NSAIDs decrease prostaglandin synthesis. diphenhydramine will increase the level or effect of propranolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.propylhexedrineMonitor Closely (1)diphenhydramine increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.protamineMonitor Closely (1)protamine and ibuprofen both increase anticoagulation. Modify Therapy/Monitor Closely.protriptylineMonitor Closely (2)diphenhydramine and protriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor. diphenhydramine and protriptyline both increase sedation. Use Caution/Monitor.pyridostigmineMonitor Closely (1)pyridostigmine increases and diphenhydramine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.quazepamMonitor Closely (1)diphenhydramine and quazepam both increase sedation. Use Caution/Monitor.quetiapineMonitor Closely (4)diphenhydramine decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. diphenhydramine decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor. quetiapine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. diphenhydramine and quetiapine both increase sedation. Use Caution/Monitor.quinaprilMonitor Closely (1)quinapril, ibuprofen. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly in elderly or volume depleted individuals.Serious - Use Alternative (1)ibuprofen, quinapril. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Coadministration may result in a significant decrease in renal function. NSAIDs may diminish the antihypertensive effect of ACE inhibitors. The mechanism of these interactions is likely related to the ability of NSAIDs to reduce the synthesis of vasodilating renal prostaglandins.quinidineSerious - Use Alternative (1)quinidine, diphenhydramine. Mechanism: pharmacodynamic synergism. Contraindicated. Risk of prolonged QTc interval.ramelteonMonitor Closely (1)diphenhydramine and ramelteon both increase sedation. Use Caution/Monitor.ramiprilMonitor Closely (1)ramipril, ibuprofen. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly in elderly or volume depleted individuals.Serious - Use Alternative (1)ibuprofen, ramipril. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Coadministration may result in a significant decrease in renal function. NSAIDs may diminish the antihypertensive effect of ACE inhibitors. The mechanism of these interactions is likely related to the ability of NSAIDs to reduce the synthesis of vasodilating renal prostaglandins.rapacuroniumMonitor Closely (1)diphenhydramine and rapacuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.reishiMonitor Closely (1)ibuprofen and reishi both increase anticoagulation. Use Caution/Monitor.reteplaseMonitor Closely (1)ibuprofen and reteplase both increase anticoagulation. Use Caution/Monitor. Potential for increased risk of bleeding, caution is advised.rifampinMinor (1)rifampin will decrease the level or effect of ibuprofen by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.rifapentineMinor (1)rifapentine will decrease the level or effect of ibuprofen by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.risperidoneMonitor Closely (4)diphenhydramine decreases levels of risperidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. diphenhydramine decreases levels of risperidone by pharmacodynamic antagonism. Use Caution/Monitor. risperidone increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia. diphenhydramine and risperidone both increase sedation. Use Caution/Monitor.Minor (1)diphenhydramine will increase the level or effect of risperidone by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.rivaroxabanMonitor Closely (1)rivaroxaban, ibuprofen. Other (see comment). Use Caution/Monitor. Comment: NSAIDs are known to increase bleeding. Bleeding risk may be increased when NSAIDs are used concomitantly with rivaroxaban. Monitor for signs/symptoms of blood loss.rivastigmineMonitor Closely (1)rivastigmine increases toxicity of ibuprofen by pharmacodynamic synergism. Use Caution/Monitor. Monitor patients for symptoms of active or occult gastrointestinal bleeding.rocuroniumMonitor Closely (1)diphenhydramine and rocuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.rose hipsMinor (1)rose hips will increase the level or effect of ibuprofen by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.sacubitril/valsartanMonitor Closely (3)sacubitril/valsartan, ibuprofen. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: May result in renal function deterioration, particularly in elderly or volume depleted individuals. ibuprofen decreases effects of sacubitril/valsartan by pharmacodynamic antagonism. Modify Therapy/Monitor Closely. NSAIDs decrease synthesis of vasodilating renal prostaglandins, and thus affect fluid homeostasis and may diminish antihypertensive effect. sacubitril/valsartan and ibuprofen both increase serum potassium. Use Caution/Monitor.sageMinor (1)diphenhydramine and sage both increase sedation. Minor/Significance Unknown.salicylates (non-asa)Monitor Closely (2)ibuprofen and salicylates (non-asa) both increase anticoagulation. Use Caution/Monitor. ibuprofen and salicylates (non-asa) both increase serum potassium. Use Caution/Monitor.Minor (1)ibuprofen will increase the level or effect of salicylates (non-asa) by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.salmeterolMonitor Closely (2)diphenhydramine increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. ibuprofen increases and salmeterol decreases serum potassium. Effect of interaction is not clear, use caution. Use Caution/Monitor.salsalateMonitor Closely (2)ibuprofen and salsalate both increase anticoagulation. Use Caution/Monitor. ibuprofen and salsalate both increase serum potassium. Use Caution/Monitor.Minor (1)ibuprofen will increase the level or effect of salsalate by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.saw palmettoMonitor Closely (1)saw palmetto increases toxicity of ibuprofen by unspecified interaction mechanism. Use Caution/Monitor. May increase risk of bleeding.scopolamineMonitor Closely (1)diphenhydramine and scopolamine both decrease cholinergic effects/transmission. Use Caution/Monitor.scullcapMonitor Closely (1)diphenhydramine and scullcap both increase sedation. Use Caution/Monitor.secobarbitalMonitor Closely (1)diphenhydramine and secobarbital both increase sedation. Use Caution/Monitor.Minor (1)secobarbital will decrease the level or effect of ibuprofen by affecting hepatic enzyme CYP2C9/10 metabolism. Minor/Significance Unknown.sertralineMonitor Closely (1)sertraline, ibuprofen. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of upper GI bleeding. SSRIs inhib. serotonin uptake by platelets.sevofluraneMonitor Closely (1)sevoflurane and diphenhydramine both increase sedation. Use Caution/Monitor.shepherd's purseMonitor Closely (1)diphenhydramine and shepherd's purse both increase sedation. Use Caution/Monitor.Siberian ginsengMinor (1)Siberian ginseng increases effects of diphenhydramine by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.silodosinMonitor Closely (1)ibuprofen decreases effects of silodosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.siponimodSerious - Use Alternative (1)ibuprofen will increase the level or effect of siponimod by affecting hepatic enzyme CYP2C9/10 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with drugs that cause moderate CYP2C9 AND a moderate or strong CYP3A4 inhibition is not recommended. Caution if siponimod coadministered with moderate CYP2C9 inhibitors alone.sodium oxybateSerious - Use Alternative (1)diphenhydramine, sodium oxybate. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant