How many days after starting vyvanse (lisdexamfetamine) should i get my blood pressure and heart rate checked? i only take it when needed. should i be on it when check?

6 and 12 hours: This drug is metabolized into Dextroamphetamine which has a half life of 12 hours. If you're taking single, sporadic doses, you should take your BP and hr at 6 and 12 hours after the first dose and anytime the dose is increased. If you take it on a regular basis, you'll see peak effects about 3-5 days after beginning it and should check your vital signs then.