The Serious Trouble with Isabella

When Isabella catches a terrible cold, Phineas and Ferb invent a medicine that drives Isabella incane. Doofenshmirtz plans to make people sick after childhood loss.

Songs

 * "I'm Feeling Sick"
 * "Gotta Help Isabella!"
 * "Quirky Worky Song"

The "Too Young" Line
"Aren't you a little sick to be having ginger ale?"

Ferb's Line
"I WANNA RUN!"

Whatcha Doin'?
Phineas when they arrive at Isabella's

Continuity
None Seen

Allusions

 * Ferb's line is a title to the Webkinz music video, "I Wanna Run."