Phenylephrine Imipramine

Clinically important, potentially hazardous interactions with albuterol, alpha-blockers, amitriptyline, amoxapine, atenolol, beta-blockers, carteolol, chlorpromazine, clomipramine, cocaine, desipramine, doxepin, ephedra, ergotamine, furazolidone, halothane, imipramine, insulin detemir, MAO inhibitors, metoprolol, nadolol, nortriptyline, oxprenolol, penbutolol, phenelzine, phenoxybenzamine, phenylephrine, pindolol, prazosin, propranolol, protriptyline, sympathomimetics, terbutaline, thioridazine, timolol, tranylcypromine, tricyclic antidepressants, trimipramine, vasopressors... 

Clinically important, potentially hazardous interactions with amitriptyline, amoxapine, amphetamines, bupropion, citalopram, clomipramine, cyproheptadine, desipramine, dextroamphetamine, dextromethorphan, diethylpropion, dopamine, doxepin, entacapone, ephedra, ephedrine, epinephrine, fluoxetine, fluvoxamine, ginseng, imipramine, levodopa, mazindol, meperidine, methamphetamine, nefazodone, nortriptyline, paroxetine, phendimetrazine, phentermine, phenylephrine, pizotifen, propoxyphene, protriptyline, pseudoephedrine, rizatriptan, sertraline, sibutramine, sumatriptan, sympathomimetics, tramadol, tricyclic antidepressants, trimipramine, tryptophan, venlafaxine, zolmitriptan... 

The manufacturer recommends caution when atomoxetine is given concurrently with other drugs that affect noradrenaline, because of the potential for additive or synergistic pharmacological effects. Examples they name are antidepressants such as imipramine, venlafaxine and mirtaza-pine, and the decongestants pseudoephedrine or phenylephrine. Until more is known, this would seem a sensible precaution. 

The pressor effects of intravenous infusions of noradrenaline were increased four to eightfold, of adrenaline two to fourfold, and of phenylephrine two to threefold in 4 healthy subjects who had been taking imipramine 75 mg daily for 5 days. There were no noticeable or consistent changes in their response to isoprenaline (isoproterenol). However, in a study of possible adverse interactions between imipramine and isoprenaline, although no abnormalities of heart rhythm were seen, one out of the 4 healthy subjects studied showed potentiation of isoprenaline- induced tachycardia. ... 

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