Donald,
I am not a doctor, but there is some information available that suggests SSRI's can lower blood sugar levels, causing hypoglycemia.
Here is some research:
Hypoglycemia associated with high doses of sertraline and sulphonylurea compound in a noninsulin-dependent diabetes mellitus patient.Sertraline-induced hypoglycemia.Sertraline-induced hyperglycemia: case report.Here is one discussing hypoglycemia resulting from the use of fluoxetine (Paxil) which is also an SSRI:
http://www.pubmedcentral.gov/articlerender...ubmedid=8775944Hyperglycemia induced by acute central fluoxetine administration: role of the central CRH system and 5-HT3 receptors.It seems that some SSRI's (I did not find much on Wellbutrin) may have hypo or hyper effects on bloog sugar levels.
Some of the side effects your friend is experiencing may not be related to hypoglycemia, though it is entirely possible that they are. The following is taken directly from the manufacturer's Wellbutrin XL fact sheet:
Common side effects reported in studies of major depressive disorder include weight loss, loss of appetite, dry mouth, skin rash, sweating, ringing in the ears, shakiness, stomach pain, agitation, anxiety, dizziness, trouble sleeping, muscle pain, nausea, fast heartbeat, sore throat, and urinating more often.
I would highly recommend your friend see a doctor, and if necessary, get a second opinion.
I hope that the information above helps you to find what you're looking for.
Stefford