Complex sentence: In some cases adenosine can make patients' limbs feel numb for about 2-5 minutes after administration intravenously depending on the dosage (usually above 12mg), during the emidiant effect of the drug patients will be in pain for about 2-10 seconds.
Split into simpler sentences: In some cases adenosine can make patients' limbs feel numb for about 2-5 minutes after administration intravenously depending on the dosage (usually above 12mg). During the immediate effect of the drug, patients will be in pain for about 2-10 seconds.