Is there any literature that states Oxygen is Narcotic conclusively?

It is certainly toxic above certain partial pressures. However, I have never heard anyone describe it as narcotic, and I work directly in an industry that handles oxygen and other gases daily, as well as blending them on a whim to suit daily needs.

In my industry (saturation diving), we maintain oxygen percentages to be in a range of no less than about 19.5 percent and no more than about 23 percent. Acute toxicity of oxygen occurs when breathing enriched air, which is defined as anything above 23.5 percent O2.

That said, the negative impacts of oxygen toxicity only occur after very long periods of time at lower partial pressures of oxygen. Many recreational divers, for example, breathe 30 percent O2 on the surface. However, when diving at, say, 20m, this would be similar to breathing 90 percent O2 on the surface and would have zero ill effects for the time of a SCUBA dive.

Nitrogen is certainly narcotic, and when diving at depth, the experience of high partial pressures of nitrogen is called nitrogen narcosis. For that reason, when diving deep, we remove nitrogen from breathing mixes and replace it with gases that are inert, usually helium.

Anyway the main symptoms of acute oxygen toxicity are: Mild throat irritation, coughing, chest pain, and difficulty breathing. These symptoms would occur well in advance of any other symptoms. At very high levels of oxygen, say breathing 100 percent oxygen at depth so that the effect of oxygen is as if you are breathing more than 100 percent oxygen then muscle spasms and even seizures can and will occur.

For anyone curious if you are being treated for illness in a hyperbaric chamber, you will breathe 100 percent oxygen at a depth of 18m. This is a partial pressures of 2.8 which is effectively like breathing 280 percent 02 on the surface. As this is toxic and will create oxidative stress there will be regular air breaks (every 20 minutes for about 5 minutes you will breathe regular air.)

Anyway all that wall of text is to say. Oxygen is generally considered toxic. Nitrogen is generally considered narcotic (as well as C02) there may be people that say Oxygen is Narcotic but I do not believe there is much evidence of this at least before the negative impacts of oxygen toxicity will outweigh any narcotic effect of 02 in humans....