No, large doses of different drugs have very different effects. Massive doses of caffeine will make you anxious, shaky, and give you heart palpitations, but it won't make you have sex all night long or hyperfocus like amphetamine.

The reason large doses of methamphetamine have very similar effects to large doses of amphetamine is not that in large doses, all drugs are similar; it's that methamphetamine is very similar to amphetamine.