Is the benefit of antibiotics for children due to excipients?

I recently had the opportunity to witness first hand the effects of amoxicillin syrup (sugar-free) on a child, who would perk up dramatically (almost bouncing off the walls) within minutes of each dose. It seems highly unlikely to me that this is due to amoxicillin itself. Could it be due to the other ingredients in the medicine (excipients)? Could this be why some parents are so keen for doctors to prescribe antibiotics?

The brand of this preparation was Bristol Laboratories and contained the following excipients, beside which I have inserted the comments of pharmacist +Cathy Cooke):

• Sodium benzoate (E211)
• Not recommended for consumption by children as food additive
• Disodium edetate
• Sodium citrate
• Citric acid anhydrous
• Sorbitol (E420)
• Not recommended for kids < 1yrs
• Saccharin sodium
• Gum Arabic
• Amyl acetate
• Amyl valerianate
• Orange oil
• Quinolone yellow (E104)
• Banned in most countries. Not recommended in children!
• Xanthan gum

If only parents could buy this stuff without the antibiotic itself!