Lisdexamfetamineinteractions

Acidifying and Alkalinizing Agents: Agents that alter urinary pH can alter blood levels of amphetamine. Acidifying agents decrease amphetamine blood levels, while alkalinizing agents increase amphetamine blood levels. Adjust VYVANSE dosage accordingly.

7.1 Drugs Having

Clinically Important Interactions with Amphetamines Table 5 Drugs having clinically important interactions with amphetamines. MAO Inhibitors (MAOI) Clinical Impact MAOI antidepressants slow amphetamine metabolism, increasing amphetamines effect on the release of norepinephrine and other monoamines from adrenergic nerve endings causing headaches and other signs of hypertensive crisis. Toxic neurological effects and malignant hyperpyrexia can occur, sometimes with fatal results. Intervention Do not administer VYVANSE during or within 14 days following the administration of MAOI. Serotonergic Drugs Clinical Impact The concomitant use of VYVANSE and serotonergic drugs increases the risk of serotonin syndrome. Intervention Initiate with lower doses and monitor patients for signs and symptoms of serotonin syndrome, particularly during VYVANSE initiation or dosage increase. If serotonin syndrome occurs, discontinue VYVANSE and the concomitant serotonergic drug(s). CYP2D6 Inhibitors Clinical Impact The concomitant use of VYVANSE and CYP2D6 inhibitors may increase the exposure of dextroamphetamine, the active metabolite of VYVANSE compared to the use of the drug alone and increase the risk of serotonin syndrome. Intervention Initiate with lower doses and monitor patients for signs and symptoms of serotonin syndrome particularly during VYVANSE initiation and after a dosage increase. If serotonin syndrome occurs, discontinue VYVANSE and the CYP2D6 inhibitor. Alkalinizing Agents Clinical Impact Urinary alkalinizing agents can increase blood levels and potentiate the action of amphetamine. Intervention Co-administration of VYVANSE and urinary alkalinizing agents should be avoided. Acidifying Agents Clinical Impact Urinary acidifying agents can lower blood levels and efficacy of amphetamines. Intervention Increase dose based on clinical response. Tricyclic Antidepressants Clinical Impact 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. Intervention Monitor frequently and adjust or use alternative therapy based on clinical response.

7.2 Interference with

Laboratory Test Allow for an adequate washout period between administration of VYVANSE and radioactive diagnostic agents used for dopamine transporter (DAT) visualization. VYVANSE can interfere with the test results of a radioactive diagnostic agent (ioflupane I-123) that is used for DAT visualization by binding and internalization of the DAT, which may result in lower DAT in the striatum. This may lead to false-positive diagnostic results.