Epinephrine at a 1:50,000 concentration provides how many micrograms (mcg) per mL?

A 1:50,000 concentration means 1 gram of drug per 50,000 mL of solution. 1 gram = 1,000,000 mcg, so 1,000,000 mcg ÷ 50,000 mL = 20 mcg/mL. (For comparison, 1:100,000 epinephrine — the most common dental cartridge concentration — works out to 10 mcg/mL.)