Most "Heroine" overdoses lately that have been on the news are actually Fentanyl overdoses. Don't underestimate the power of Fentanyl. It's easy to add but not to take away. Honestly, if you don't know what you are doing, please ask someone for advice. Also, the above advice is good, if you don't have a ug scale then don't try to guess. My daughter who is totally opiate naive was given 3 micro grams with her epidural. It made her loopy. So, you do the math in regards to 10mg's.. With 10mg that would give her 3,333.333 doses. Just to put it into perspective. When I looked at the bag that was hanging next to her, it had 750ug's in the entire bag. In 18 hours, she only used about 1/10th of it.. It's not to be taken lightly...