Can you work out why he has sore paws?
Is he sittting on damp/dirty bedding or is he gnawing his feet /barbering himself?
There's a condition called Bumblefoot which is bacterial and usually stems from damage or dirty wet bedding . (When I see photos of people advertising guinea pig sat on the bars of the cage I'm inwardly howling Noooooooooooo )
With your previous piggie , often by the time you realise they need antibiotics they're pretty far gone , it might have been that . Also they need pre-biotics alongside antibiotics to keep their gut flora in synch . They're complex little things .
I have used coconut oil on one of our old pigs , mainly round his ears as he was Teddy and they do suffer dry skin. I was thinking too "its edible" but only a smidgeon warmed on my hand and applied .
Then some melted and cooled in hot water pre-wash for his dry skin.
If he's got sore feet then a warm saline paw bath might soothe (and again, salt is edible)
Gorgeous Guineas sell a couple - F&M or Perfect Paws cream
There's a Calendula (Marigold) which is soothing cream
I've just searched up the meds you've got , it says it contained Meloxicam which is a painkiller /anti-inflammatory
We had it for GP3 post castration, I think 2 days worth but there was enough for 3 days (Vet gave a bit more ) He lapped it up , and I can imagine he felt a bit achey after that little operation!
What Id try meantime is
Hay only to eat , put it in a loo roll tube to keep it in place or the solid hay biscuits (they need hay 24/7)
No shavings etc
Towel or soft fleece for bedding with either a puppy pad under the upper layer or newspaper to absorb
Change it as soon as there's any damp on it .
They're lazy little mammals and sometimes don't move much , especially if they're poorly 