Yes, in sufficient quantities. Drugs such as demerol can magnify the side-effects (enhance CNS suppression which is what will lead to death). Alcohol also magnifies the effect.
To get it prescribed will take some work. It can be used to treat insomnia but providers will typically avoid prescribing it until all other avenues have been exhausted (sleep hygiene, OTC medications, lunesta, ambien etc) have all be tried due to the addictive and dangerous nature that Seconal can have.
Not saying it's impossible and it really all depends on who your medical provider is and what their operation procedures are before trying seconal.