No, it was never intended as a weapon. The helmet that bore the spike was made out of leather with some brass fittings and ornaments. It was thus not fitted to anything that was strong enough to support it being used as a weapon.

As you can see from photos such as these the German troops wore a cloth covering over both the helmet and the spike as part of their field uniform, which would make it even less usefull as any kind of weapon.

German troops used their rifles, bayonets, sharpened field spades, trench bludgeons and many other weapons in trench warfare, but I have never encountered an account of them using their pickelhaube as a weapon.