The number of milligrams $D(h)$ of a drug in a patient's bloodstream $h$ hours after the drug is injected. is modeled by the following function.
\[
D(h)=50 e^{-0.2 h}
\]
Find the initial amount injected and the amount in the bloodstream after 7 hours.
Round your answers to the nearest hundredth as necessary.

Step 1 ：The initial amount of the drug injected can be found by evaluating the function at \(h=0\).

Step 2 ：Substitute \(h=0\) into the function \(D(h)=50 e^{-0.2 h}\) to get \(D(0)=50 e^{-0.2*0}=50.0\).

Step 3 ：The amount of the drug in the bloodstream after 7 hours can be found by evaluating the function at \(h=7\).

Step 4 ：Substitute \(h=7\) into the function \(D(h)=50 e^{-0.2 h}\) to get \(D(7)=50 e^{-0.2*7}\) which is approximately 12.33.

Step 5 ：Final Answer: The initial amount of the drug injected is \(\boxed{50.0}\) milligrams and the amount in the bloodstream after 7 hours is approximately \(\boxed{12.33}\) milligrams.