Give someone a taste of their own medicine is the present tense of gave someone a taste of their own medicine.
The third-person singular simple present indicative form of give someone a taste of their own medicine is gives someone a taste of their own medicine.
The present participle of give someone a taste of their own medicine is giving someone a taste of their own medicine.
The past participle of give someone a taste of their own medicine is given someone a taste of their own medicine.
