This is just another caution to keep medications out of the reach of your pets, and if you drop a pill on the floor by accident and your dog eats it before you can take it away, be sure to call a poison hotline or visit an emergency vet immediately. Below is a research article case study of a Yorkie who died after consuming over-the-counter caffeine pills:
Fatal caffeine intoxication in a dog | Hensel | Brazilian Journal of Veterinary Pathology
If that link is behind a paywall, here is a link to the abstract:
Fatal caffeine intoxication in a dog | Hensel | Brazilian Journal of Veterinary Pathology
Note: This dog wasn't taken to the vet until 6 to 8 hours after it had eaten the pills. If it had been taken to the vet sooner, it might have survived.