This is taken directly from the drugs section of Psych Central....

Risperdal

Possible Side Effects
This medicine can cause the following side effects:
constipation
dizziness
drowsiness
dry mouth
headache
weight gain
restlessness
mild thirst
frequent urination
drowsiness
fine hand tremor
mild nausea
Check with your doctor AS SOON AS POSSIBLE if you experience diarrhea, vomiting, unsteadiness, difficulty walking, or unusual muscle weakness.
This medicine may increase blood sugar (hyperglycemia). Diabetic patients should be cautious of this and regularly check their blood sugar.

Maybe you could have your pharmacist inform the doctor of this side effect?