Amphetamineinteractions

MAO Inhibitors Concomitant use of MAOIs and CNS stimulants can cause hypertensive crisis. Potential outcomes include death, stroke, myocardial infarction, aortic dissection, ophthalmological complications, eclampsia, pulmonary edema, and renal failure. Do not administer Mixed Salts of a Single Entity Amphetamine Product concomitantly or within 14 days after discontinuing MAOI ( see CONTRAINDICATIONS and WARNINGS ). Serotonergic Drugs The concomitant use of Mixed Salts of a Single Entity Amphetamine Product and serotonergic drugs increases the risk of serotonin syndrome. Initiate with lower doses and monitor patients for signs and symptoms of serotonin syndrome, particularly during Mixed Salts of a Single Entity Amphetamine Product initiation or dosage increase. If serotonin syndrome occurs, discontinue Mixed Salts of a Single Entity Amphetamine Product and the concomitant serotonergic drug(s) ( see WARNINGS and PRECAUTIONS ). CYP2D6 Inhibitors The concomitant use of Mixed Salts of a Single Entity Amphetamine Product and CYP2D6 inhibitors may increase the exposure of Mixed Salts of a Single Entity Amphetamine Product compared to the use of the drug alone and increase the risk of serotonin syndrome. Initiate with lower doses and monitor patients for signs and symptoms of serotonin syndrome particularly during Mixed Salts of a Single Entity Amphetamine Product initiation and after a dosage increase. If serotonin syndrome occurs, discontinue Mixed Salts of a Single Entity Amphetamine Product and the CYP2D6 inhibitor ( see WARNINGS and OVERDOSAGE ). Acidifying Agents Lower blood levels and efficacy of amphetamines. Increase dose based on clinical response. Examples of acidifying agents include gastrointestinal acidifying agents and urinary acidifying agents. Adrenergic Blockers Adrenergic blockers are inhibited by amphetamines. Alkalinizing Agents Increase blood levels and potentiate the action of amphetamine. Co-administration of Mixed Salts of a Single Entity Amphetamine Product and gastrointestinal alkalinizing agents should be avoided. Examples of alkalinizing agents include gastrointestinal alkalinizing agents and urinary alkalinizing agents. Tricyclic Antidepressants May enhance the activity of tricyclic or sympathomimetic agents causing striking and sustained increases in the concentration of d-amphetamine in the brain; cardiovascular effects can be potentiated. Monitor frequently and adjust or use alternative therapy based on clinical response. Antihistamines Amphetamines may counteract the sedative effect of antihistamines. Antihypertensives Amphetamines may antagonize the hypotensive effects of antihypertensives. Chlorpromazine Chlorpromazine blocks dopamine and norepinephrine receptors, thus inhibiting the central stimulant effects of amphetamines, and can be used to treat amphetamine poisoning. Ethosuximide Amphetamines may delay intestinal absorption of ethosuximide. Haloperidol Haloperidol blocks dopamine receptors, thus inhibiting the central stimulant effects of amphetamines. Lithium Carbonate The anorectic and stimulatory effects of amphetamines may be inhibited by lithium carbonate. Meperidine Amphetamines potentiate the analgesic effect of meperidine. Methenamine Therapy Urinary excretion of amphetamines is increased, and efficacy is reduced, by acidifying agents used in methenamine therapy. Norepinephrine Amphetamines enhance the adrenergic effect of norepinephrine. Phenobarbital Amphetamines may delay intestinal absorption of phenobarbital; coadministration of phenobarbital may produce a synergistic anticonvulsant action. Phenytoin Amphetamines may delay intestinal absorption of phenytoin; coadministration of phenytoin may produce a synergistic anticonvulsant action. Propoxyphene In cases of propoxyphene overdosage, amphetamine CNS stimulation is potentiated and fatal convulsions can occur. Proton Pump Inhibitors Time to maximum concentration (T max ) of amphetamine is decreased compared to when administered alone. Monitor patients for changes in clinical effect and adjust therapy based on clinical response. An example of a proton pump inhibitor is omeprazole. Veratrum Alkaloids Amphetamines inhibit the hypotensive effect of veratrum alkaloids.