It's bad to stop taking your prescriptions.
Alistair is taking a medication whose side effect is weight gain.
Alistair wants to stop gaining weight.
Alistair consults with their doctor to find a new medication that won't cause him to gain weight.
Alistair goes off their medication.
Alistair switches to a new medication that keeps their weight and their health under control.
Alistair stops gaining weight but his health deteriorates.