Kesha has just begun taking a new drug that produces side effects like muscular rigidity and tremors. based on this information, kesha's drug may be acting on her system

The answer is, The drug may be acting on her "dopamine system".

The dopamine system is essentially a gathering of nerve cells, the greater part of which begins in the midbrain. They send their axons to the forebrain, to various parts of the forebrain, where they connect to specific capacities

answer; fair labor and standard act;

explanation:

allergens: overstimulate the nerve system

neurotics: attack nerve cells

mutagens: damage or otherwise alter dna sequence

generators: cause defects during growth and development  

carcinogens: cause unchecked cell growth

i hope you get the idea according to me these are the effects that happened.