My dog seems lethargic (updated)

Hi there

My six years old chocolate labrador Max has been taking Rilexine Antibiotics for 4 weeks as treatment for an infected pressure sore and acne. He is very lethargic could this be a side effect of the drugs?

http://www.dogsey.com/showthread.php?t=54649

http://www.virbac.com.au/p-virbacaup...%20Tablets.pdf

Max was not himself at all last week, very tired - even too tired to stand by me whilst I got his meals ready. I was concerned about the antibiotics he was on - Rilexine. After getting a reply and further investigation it seems this is one of the side effects. I decided not to give him any more as he had been on them for 4 weeks and his acne and sore seems ok. I am pleased to say I saw an improvement in less than 24 hours and now he is back to his old mischeivious self. Thanks for your help.