affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.paroxetineSerious - Use Alternative (1)paroxetine will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.peginterferon alfa 2bMonitor Closely (1)peginterferon alfa 2b, methamphetamine. Other (see comment). Use Caution/Monitor. Comment: When patients are administered peginterferon alpha-2b with CYP2D6 substrates, the therapeutic effect of these drugs may be altered. Peginterferon alpha-2b may increase or decrease levels of CYP2D6 substrate.pentazocineMonitor Closely (1)pentazocine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.pentobarbitalMonitor Closely (1)pentobarbital increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.perphenazineMonitor Closely (3)perphenazine will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. perphenazine, methamphetamine. 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 methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.phendimetrazineMonitor 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.phenelzineContraindicated (1)phenelzine increases effects of methamphetamine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.phenobarbitalMonitor Closely (1)phenobarbital increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.phentermineMonitor Closely (2)methamphetamine and phentermine both decrease sedation. Use Caution/Monitor. methamphetamine and phentermine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.phenylephrineMonitor Closely (2)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.phenylephrine POMonitor Closely (2)methamphetamine and phenylephrine PO both decrease sedation. Use Caution/Monitor. methamphetamine and phenylephrine PO both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.pholcodineMonitor Closely (1)pholcodine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.pimozideMonitor Closely (1)pimozide increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.pirbuterolMonitor Closely (2)pirbuterol and methamphetamine both decrease sedation. Use Caution/Monitor. pirbuterol and methamphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.primidoneMonitor Closely (1)primidone increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.procarbazineContraindicated (1)procarbazine increases effects of methamphetamine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.prochlorperazineMonitor Closely (2)prochlorperazine, methamphetamine. 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 methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.promazineMonitor Closely (1)promazine, methamphetamine. 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, methamphetamine. 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 methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.propafenoneMonitor Closely (1)propafenone will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.propylhexedrineMonitor Closely (2)methamphetamine and propylhexedrine both decrease sedation. Use Caution/Monitor. methamphetamine and propylhexedrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.protriptylineMonitor Closely (1)protriptyline increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)protriptyline, methamphetamine. 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)methamphetamine and pseudoephedrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.quazepamMonitor Closely (1)quazepam increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.quetiapineMonitor Closely (1)quetiapine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.quinacrineMonitor Closely (1)quinacrine will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.quinidineSerious - Use Alternative (1)quinidine will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.rabeprazoleMinor (1)rabeprazole decreases levels of methamphetamine by Other (see comment). Minor/Significance Unknown. Comment: Time to maximum concentration (Tmax) of amphetamine is decreased compared to when administered alone; monitor patients for changes in clinical effect and adjust therapy based on clinical response.ranolazineMonitor Closely (1)ranolazine will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.rasagilineContraindicated (1)rasagiline increases effects of methamphetamine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode. Coadministration is contraindicated during or within 14 days following the administration of MAOIs.risperidoneMonitor Closely (1)risperidone increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.ritonavirMonitor Closely (1)ritonavir will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.rolapitantMonitor Closely (1)rolapitant will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Rolapitant may increase plasma concentrations of CYP2D6 substrates for at least 28 days following rolapitant administration.safinamideContraindicated (1)methamphetamine, 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 methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Minor/Significance Unknown.salmeterolMonitor Closely (2)salmeterol and methamphetamine both decrease sedation. Use Caution/Monitor. salmeterol and methamphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.scullcapMonitor Closely (1)scullcap increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.secobarbitalMonitor Closely (1)secobarbital increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.selegilineContraindicated (1)selegiline increases effects of methamphetamine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode. Coadministration is contraindicated during or within 14 days following the administration of MAOIs.selegiline transdermalContraindicated (1)selegiline transdermal increases effects of methamphetamine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.serdexmethylphenidate/dexmethylphenidateMonitor Closely (2)serdexmethylphenidate/dexmethylphenidate and methamphetamine both decrease sedation. Use Caution/Monitor. serdexmethylphenidate/dexmethylphenidate and methamphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.sertralineMonitor Closely (1)sertraline will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.sevofluraneSerious - Use Alternative (1)sevoflurane increases toxicity of methamphetamine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.shepherd's purseMonitor Closely (1)shepherd's purse increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.sodium acid phosphateMonitor Closely (1)sodium acid phosphate decreases levels of methamphetamine by increasing renal clearance. Use Caution/Monitor.solriamfetolMonitor Closely (1)methamphetamine and solriamfetol both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.sufentanilMonitor Closely (1)sufentanil increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.sufentanil SLMonitor Closely (1)sufentanil SL, methamphetamine. Either increases effects of the other by serotonin levels. Use Caution/Monitor. Coadministration of drugs that affect the serotonergic neurotransmitter system may result in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment.tapentadolMonitor Closely (1)tapentadol increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.tedizolidSerious - Use Alternative (1)tedizolid, methamphetamine. Either increases effects of the other by Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. both increase serotonin levels; increased risk of serotonin syndrome.temazepamMonitor Closely (1)temazepam increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.terbinafineMonitor Closely (1)terbinafine will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.terbutalineMonitor Closely (2)terbutaline and methamphetamine both decrease sedation. Use Caution/Monitor. terbutaline and methamphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.thioridazineMonitor Closely (3)thioridazine will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. thioridazine, methamphetamine. 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. thioridazine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.thiothixeneMonitor Closely (1)thiothixene increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.tipranavirMonitor Closely (1)tipranavir will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.topiramateMonitor Closely (1)topiramate increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.tramadolMonitor Closely (1)tramadol increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.tranylcypromineContraindicated (1)tranylcypromine increases effects of methamphetamine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.trazodoneMonitor Closely (2)trazodone increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. trazodone increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Significant - Monitor Closely.. methamphetamine increases toxicity of trazodone by Other (see comment). Use Caution/Monitor. Comment: Amphetamines may increase the toxicity of serotonin modulators, increasing the risk of serotonin syndrome. .triazolamMonitor Closely (1)triazolam increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.triclofosMonitor Closely (1)triclofos increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.trifluoperazineMonitor Closely (2)trifluoperazine, methamphetamine. 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. trifluoperazine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.trimipramineMonitor Closely (1)trimipramine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)trimipramine, methamphetamine. 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.triprolidineMonitor Closely (1)triprolidine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.venlafaxineMonitor Closely (1)venlafaxine will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.vilazodoneSerious - Use Alternative (1)methamphetamine, vilazodone. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug. Concomitant therapy should be discontinued immediately if signs or symptoms of serotonin syndrome emerge and supportive symptomatic treatment should be initiated. .xylometazolineMonitor Closely (2)methamphetamine and xylometazoline both decrease sedation. Use Caution/Monitor. methamphetamine and xylometazoline both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.yerba mateMinor (1)yerba mate increases effects of methamphetamine by pharmacodynamic synergism. Minor/Significance Unknown.yohimbeSerious - Use Alternative (1)yohimbe, methamphetamine. Mechanism: pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.yohimbineMonitor Closely (2)methamphetamine and yohimbine both decrease sedation. Use Caution/Monitor. methamphetamine and yohimbine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.ziconotideMonitor Closely (1)ziconotide increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.ziprasidoneMonitor Closely (1)ziprasidone increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. Frequency Not Defined Common Hypertension, palpitations, tachyarrhythmia Dizziness, drug tolerance, dysphoric mood, euphoria, headache, insomnia, restlessness, tremor Urticaria Constipation, diarrhea, taste sense altered, xerostomia Serious Cardiorespiratory arrest, sudden death (rare), myocardial infarction Cerebrovascular accident, Gilles de la Tourette's syndrome, seizure, psychotic disorder Also see sympathomimetic syndrome, amphetamine toxicity Musculoskeletal: Rhabdomyolysis Postmarketing Reports Alopecia Intestinal ischemia Black Box Warnings Amphetamine has a high potential for abuse. Particular attention should be paid to the possibility of patients obtaining amphetamine for nontherapeutic use or distribution to others, and the drugs should be prescribed or dispensed sparingly Administration of amphetamine for prolonged periods of time may lead to drug dependence and must be avoided Use therapy in weight reduction programs when alternative therapy has been ineffective Misuse of amphetamine may cause sudden death and serious cardiovascular adverse eventsContraindications Within 14 days of MAOIs Advanced arteriosclerosis Symptomatic cardiovascular disease Hyperthyroidism Moderate-severe hypertension Hypersensitivity to sympathomimetic amines Glaucoma Agitated state History of drug abuse Patients with ADHD concomitant with Tourette's syndrome Breastfeeding Cautions Difficulties with accommodation and blurring of vision reported with stimulant treatment. Methamphetamine should not be used to combat fatigue or to replace rest in normal persons Prescribing and dispensing of methamphetamine should be limited to smallest amount that is feasible at one time in order to minimize possibility of overdosage. Do not give at late evening; may cause insomnia May impair ability