Giving lysine in a multiple cat household with a ckd cat

Last week Friday I went to the vet's with my third cat who seemed to have caught the uri that the kittens had. While I was there I talked to the vet about my concern that Leonard (one of the kittens) eye was still looking irritated, had taken a picture the night before to be able to show how it was looking. The kiitens also had still been sneezing after almost completing their course of clavomax. I was given a prescription of a different antibiotic to use on the kittens and Taz my 2 year old. The other thing that my vet recommended was trying lysine in case we where dealing with feline herpes. The lysine has been working really well, by Friday night Leonard's eye looked normal, and I think the sneezing has stopped.

Riley my 13 year old boy was diagnoised with ckd a few months back and has at times been a sneezy cat. Usually nothing that has needed vet attention. Since I started the lysine his sneezing has decreased. What I am wondering is if the lysine may have any negative affect on his kidneys. I feed all my cats canned food, trying to find what I can with a low phosphorus level for Riley's sake. My adult cats tend to be grazers and share from the same food dish. Before Riley's diagnoises I had fed them a dry diet, so habits are ingrained fairly well. Also with Riley being in the late stages of ckd he tends to eat smaller meals more often which works for him. Because of this I try to keep food available most of the time. At this time the lysine doesn't seem to be making him feel worse and if anything maybe a bit better, finding him joining in the early morning play session that the younger cats where having this morning. Just wondering if anyone else has a ckd kitty that they are giving lysine to also?

I don't have any personal real-life knowledge / experience about this; Ritz' kidneys are fine.

However, I volunteer for a cat sanctuary.  They have separate rooms for:  general population (nost cats available for immediate adoption); intake area (cats with special needs and/or  medical issues or new cats);  FeLK+ room; FIV+ room; and feral cats.

ALL of them get L-lysine mixed in with wet food once a day; any cat with a URI gets an extra dose (those cats are kept in cages to prevent the spread).  The cats get wet food only once a day (free fed dry), and around noon time you can see them all congregating at the front door waiting with bated breath for the food.

AS far as I know, Lysine does not affect the kidneys. I give it daily in paste form to Wellington, to keep his herpes down, and he has had no kidney trouble, nor has any vet ever suggested it as a possibility.

I used to give my CRF kitty lysine twice a day and it didn't have any effect on her kidneys.  The only way the kidneys are involved is filtering out the toxins and since Lysine is an amino acid present in the body, I don't think there'd be a problem with it.