There is not much serious information about Fentanyl, in the final exit barely appears, just a little comment about intravenous mode, and look likes that 1mg is not enough.
In the Act for death help of Denmark where appears all medicines suitable for suicide, tells literally.
Fentanyl is available as transdermal patches under the names Durogesic , Fentanyl Mylan , Fentanyl Orion ,Fentanyl Sandoz and Matrifen as well as Abstral tongue tablets ("resoriblets") , Instanyl nasal spray and PecFent nasal spray . The body's absorption of the drug is difficult to predict individual. Fentanyl is therefore not recommended alone, but is very suitable as a last resort supplement to all other medicines.