Alternate Drug. Based on the mechanism of action of iobenguane, drugs that reduce catecholamine uptake or that deplete catecholamine stores may interfere with iobenguane uptake into cells, and thus, reduce iobenguane efficacy. Discontinue interfering drugs for at least 5 half-lives before administration of either the dosimetry or an iobenguane dose. Do not administer these drugs until at least 7 days after each iobenguane dose.isocarboxazidContraindicated (1)isocarboxazid increases effects of phendimetrazine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.isofluraneSerious - Use Alternative (1)isoflurane increases toxicity of phendimetrazine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.isoproterenolMonitor Closely (2)isoproterenol and phendimetrazine both decrease sedation. Use Caution/Monitor. isoproterenol and phendimetrazine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.ketotifen, ophthalmicMonitor Closely (1)ketotifen, ophthalmic increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.levalbuterolMonitor Closely (2)levalbuterol and phendimetrazine both decrease sedation. Use Caution/Monitor. levalbuterol and phendimetrazine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.levorphanolMonitor Closely (1)levorphanol increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.linezolidContraindicated (1)linezolid increases effects of phendimetrazine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.lisdexamfetamineMonitor Closely (2)lisdexamfetamine and phendimetrazine both decrease sedation. Use Caution/Monitor. lisdexamfetamine and phendimetrazine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.lofepramineMonitor Closely (1)lofepramine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)lofepramine, phendimetrazine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.lofexidineMonitor Closely (1)lofexidine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.loprazolamMonitor Closely (1)loprazolam increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.lorazepamMonitor Closely (1)lorazepam increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.lormetazepamMonitor Closely (1)lormetazepam increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.loxapineMonitor Closely (1)loxapine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.loxapine inhaledMonitor Closely (1)loxapine inhaled increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.maprotilineMonitor Closely (1)maprotiline increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)maprotiline, phendimetrazine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.marijuanaMonitor Closely (1)marijuana increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.melatoninMonitor Closely (1)melatonin increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.meperidineMonitor Closely (1)meperidine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.meprobamateMonitor Closely (1)meprobamate increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.metaproterenolMonitor Closely (2)metaproterenol and phendimetrazine both decrease sedation. Use Caution/Monitor. metaproterenol and phendimetrazine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.metforminMonitor Closely (1)phendimetrazine decreases effects of metformin by pharmacodynamic antagonism. Use Caution/Monitor. Patient should be closely observed for loss of blood glucose control; when drugs are withdrawn from a patient receiving metformin, patient should be observed closely for hypoglycemia.methadoneMonitor Closely (1)methadone increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.methamphetamineMonitor Closely (2)methamphetamine and phendimetrazine both decrease sedation. Use Caution/Monitor. methamphetamine and phendimetrazine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.methoxyfluraneSerious - Use Alternative (1)methoxyflurane increases toxicity of phendimetrazine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.methyldopaMonitor Closely (1)methyldopa increases effects of phendimetrazine by unknown mechanism. Use Caution/Monitor.methylenedioxymethamphetamineMonitor Closely (2)methylenedioxymethamphetamine and phendimetrazine both decrease sedation. Use Caution/Monitor. methylenedioxymethamphetamine and phendimetrazine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.methylergonovineSerious - Use Alternative (1)methylergonovine, phendimetrazine. Mechanism: pharmacodynamic synergism. Contraindicated. Additive vasospasm; risk of hypertension.methylphenidateContraindicated (1)phendimetrazine increases effects of methylphenidate by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.midazolamMonitor Closely (1)midazolam increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.midodrineMonitor Closely (2)midodrine and phendimetrazine both decrease sedation. Use Caution/Monitor. midodrine and phendimetrazine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.mirtazapineMonitor Closely (1)mirtazapine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.modafinilMonitor Closely (1)modafinil and phendimetrazine both decrease sedation. Use Caution/Monitor.morphineMonitor Closely (1)morphine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.motherwortMonitor Closely (1)motherwort increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.moxonidineMonitor Closely (1)moxonidine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.nabiloneMonitor Closely (1)nabilone increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.nalbuphineMonitor Closely (1)nalbuphine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.norepinephrineMonitor Closely (2)norepinephrine and phendimetrazine both decrease sedation. Use Caution/Monitor. norepinephrine and phendimetrazine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.nortriptylineMonitor Closely (1)nortriptyline increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)nortriptyline, phendimetrazine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.olanzapineMonitor Closely (1)olanzapine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.opium tinctureMonitor Closely (1)opium tincture increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.oxazepamMonitor Closely (1)oxazepam increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.oxycodoneMonitor Closely (1)oxycodone increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.oxymorphoneMonitor Closely (1)oxymorphone increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.oxytocinMonitor Closely (1)oxytocin increases effects of phendimetrazine by pharmacodynamic synergism. Use Caution/Monitor.ozanimodSerious - Use Alternative (1)ozanimod increases toxicity of phendimetrazine by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Avoid or Use Alternate Drug. Because the active metabolite of ozanimod inhibits MAO-B in vitro, there is a potential for serious adverse reactions, including hypertensive crisis. Therefore, coadministration of ozanimod with drugs that can increase norepinephrine or serotonin is not recommended. Monitor for hypertension with concomitant use.paliperidoneMonitor Closely (1)paliperidone increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.papaveretumMonitor Closely (1)papaveretum increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.pentazocineMonitor Closely (1)pentazocine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.pentobarbitalMonitor Closely (1)pentobarbital increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.perphenazineMonitor Closely (2)perphenazine, phendimetrazine. 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. perphenazine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.phenelzineContraindicated (1)phenelzine increases effects of phendimetrazine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.phenobarbitalMonitor Closely (1)phenobarbital increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.phentermineMonitor Closely (2)phentermine and phendimetrazine both decrease sedation. Use Caution/Monitor. phendimetrazine and phentermine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.phenylephrineMonitor Closely (2)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.phenylephrine POMonitor Closely (2)phendimetrazine and phenylephrine PO both decrease sedation. Use Caution/Monitor. phendimetrazine and phenylephrine PO both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.pholcodineMonitor Closely (1)pholcodine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.pimozideMonitor Closely (1)pimozide increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.pirbuterolMonitor Closely (2)pirbuterol and phendimetrazine both decrease sedation. Use Caution/Monitor. pirbuterol and phendimetrazine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.primidoneMonitor Closely (1)primidone increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.procarbazineContraindicated (1)procarbazine increases effects of phendimetrazine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.prochlorperazineMonitor Closely (2)prochlorperazine, phendimetrazine. 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. prochlorperazine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.promazineMonitor Closely (1)promazine, phendimetrazine. 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.promethazineMonitor Closely (2)promethazine, phendimetrazine. 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 phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.propofolMonitor Closely (1)propofol increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.propylhexedrineMonitor Closely (2)phendimetrazine and propylhexedrine both decrease sedation. Use Caution/Monitor. phendimetrazine and propylhexedrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.protriptylineMonitor Closely (1)protriptyline increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)protriptyline, phendimetrazine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.pseudoephedrineMonitor Closely (1)phendimetrazine and pseudoephedrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.quazepamMonitor Closely (1)quazepam increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.quetiapineMonitor Closely (1)quetiapine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.rasagilineSerious - Use Alternative (1)rasagiline increases effects of phendimetrazine by pharmacodynamic synergism. Avoid or Use Alternate Drug. Phendimetrazine should not be administered during or within 14 days following the use of most MAOIs or drugs with MAO-inhibiting activity. Risk of acute hypertensive episode.risperidoneMonitor Closely (1)risperidone increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.safinamideContraindicated (1)phendimetrazine, safinamide. Either increases toxicity of the other by serotonin levels. Contraindicated. Concomitant use could result in life-threatening serotonin syndrome.sageMinor (1)sage increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Minor/Significance Unknown.salmeterolMonitor Closely (2)salmeterol and phendimetrazine both decrease sedation. Use Caution/Monitor. salmeterol and phendimetrazine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.scullcapMonitor Closely (1)scullcap increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.secobarbitalMonitor Closely (1)secobarbital increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.selegilineSerious - Use Alternative (1)selegiline increases effects of phendimetrazine by pharmacodynamic synergism. Avoid or Use Alternate Drug. Phendimetrazine should not be administered during or within 14 days following the use of most MAOIs or drugs with MAO-inhibiting activity. Risk of acute hypertensive episode. .selegiline transdermalContraindicated (1)selegiline transdermal increases effects of phendimetrazine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.serdexmethylphenidate/dexmethylphenidateMonitor Closely (2)serdexmethylphenidate/dexmethylphenidate and phendimetrazine both decrease sedation. Use Caution/Monitor. serdexmethylphenidate/dexmethylphenidate and phendimetrazine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.shepherd's purseMonitor Closely (1)shepherd's purse increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.solriamfetolMonitor Closely (1)phendimetrazine and solriamfetol both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.sufentanilMonitor Closely (1)sufentanil increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.tapentadolMonitor Closely (1)tapentadol increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.temazepamMonitor Closely (1)temazepam increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.terbutalineMonitor Closely (2)terbutaline and phendimetrazine both decrease sedation. Use Caution/Monitor. terbutaline and phendimetrazine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.thioridazineMonitor Closely (2)thioridazine, phendimetrazine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely