Is Nitroglycerin sensitive to the light??

I am an escort nurse. Yesterday, when escorting a intracranial hemorrhage patient in China back to Hong Kong, I was asked to have the Nitroglycerin infusion syringe covered with opaque material by the local doctors and nuses in China. The reason for doing that they explained to me is Nitroglycerin is sensitive to the light. From my knowledge, I only know the Nipride needs to pretect from the light. I googled this after the case was done, however it did not help much. I'd appricate it if you guys can clear this up for me as I have a lot AMI patients. In addition, what do you guys think to use Nitroglycerin to control BP for a intracranial hemorrhage patient? It does not sound good to me as it would increase the venous capacitance(75% of the cranial blood volume is venous)--that's what I learned from nursing shcool. Pls correct me if i am wrong. Thanx!!