If you're worried about possible side effects, just take the prescribed dosage for full a day long before you start on your hike. If you notice anything other than the regular weird taste effects of carbonated drinks and/or beer, then follow up according to recommended procedures.
The typical side effects include numbness/tingling in the extremities. Typically that is worsened by high dosage or long duration on the drug.
I think that I had the numbness in my toes after one week at standard dosage, but it was hard to distinguish it from the effects of cold.
