SN from IC is pretty reliable. How much do you have? Since you don't have a proper antiemetic, it would be best to make a second and if possible a third glass. Vomiting will most likely occur without a proper antiemetic (it can still happen even with one), but I hear people still succeed despite vomiting when they take a second glass after vomiting. A third's just for extra assurance if in case you somehow manage to vomit again after taking the second glass, but admittedly I've never heard of that happening before.