Clindamycin
"I took this medication for a tooth infection. I have ulcers so I was concerned. My dentist told me a trick.. drink a half glass of water then eat half of your meal, take the pill, finish your meal and follow with full glass of water. Don't lay down for an hr. I followed his instructions and boom not one side effect.  No stomach pain at all. ALWAYS take with food. Medication works wonders. I take 300mg 3x a day."