This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Which of the following is an adverse effect of β2 agonists: 
Select and explain. 
A. Hypoglycemia, B. Hypomagnesemia, C. Hypophosphatemia, D. Hypokalemia
D: Hypokalemia
Answer: D: Hypokalemia 
Explanation: β2 agonists cause a brief spell of hyperkalemia followed by hypokalemia.
These do not cause hypoglycemia. However, β2 blockers delays the recovery from hypoglycemia.