I don't think I've ever been needed a late night pharmacy, but I keep a range of meds in the house, including the strongest possible OTC painkillers, so it's very rare that I would need something urgently at night.
My medicine cabinet has: paracetamol, ibuprofen, aspirin, cocodamol. (Don't have any codeine and ibuprofen though, ought to pick some up.) Ibuprofen gel. Ice packs and heat packs. Wrist and ankle supports.
Antihistamines - cream and tablets, prescription, drowsy and non drowsy. Hydrocortisone cream. Clotrimazole cream. Fluconazole.
Simethicone, mebeverine, omeprazole, ranitadine, Rennies and gaviscon, and fibogel. Loperimide, dioralyte.
And then also decongestant, and peppermint oil which I use with steam to aid decongestant.
And then bandages, plasters etc. No steristrips yet because we don't get too many major cuts and I'm much more confident in my pharmaceutical knowledge than when a cut needs stitches Vs steristrips.
I think that's it off the top of my head, but I've not actually checked the cabinet!
As you can see it's pretty well stocked, so I don't usually need to go anywhere at short notice. Looking back at it it looks kinda crazy tbh!