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.
A: Wellbutrin (bupropion) comes in several different formulations. Wellbutrin (bupropion) is immediate-release and can be dosed up to three times a day. Wellbutrin SR (bupropion sustained-release) is dosed twice a day. Wellbutrin XL (bupropion extended-release) is only to be dosed once a day. Wellbutrin XL (bupropion extended-release) is meant to last for 24 hours.