Call your doctor at once if you have a serious side effect such as: 1  headache with chest pain and severe dizziness, fast or pounding heartbeats, shortness of breath, fainting; 2  diarrhea that is watery or bloody;  fever, swollen glands, body aches, flu symptoms, new or worsening cough;
The maximum daily doses is also slightly different as both Wellbutrin XL and Wellbutrin have a maximum daily dose of 450 mg per day, whereas the maximum dosage for Wellbutrin SR is only 400 mg per day.
How Does Wellbutrin Work? Wellbutrin is a norepinephrine and dopamine reuptake inhibitor, or NDRI for short. NDRIs affect specific chemicals within the brain, known as norepinephrine and dopamine. These are two of several chemicals used to send messages from one nerve cell to another.