I know fatal or lethal doses of morphine can be considered situational, but my dad had a low tolerance to opioids, specifically morphine. He overdosed while in the hospital after surgery due to a Morphine drip. He needed Narcan and intubated.  He recovered and was discharged from the hospital.  While at home his wife administered him oral Morphine to assist him with pain management.  The frequency of administration was increased and he died within 24 hours.  We requested toxicology testing and he had the following in his system:  I’m wondering if 190 ng/mL Morphine (free blood) is within a range that can be considered lethal or fatal.
Morphine Free Blood: 190 ng/mL
Desmethylsertraline: 24 ng/mL

Selenium: 210 mcg/L
Lorazepam: 11ng/mL

Lead: .80 mcg/dL
Mercury: 3.3 mcg/L