A nurse is preparing to administer promethazine 25 mg IM to a client. Available is promethazine 50 mg/mL. How many mL should the nurse administer? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)

To calculate the correct dosage of promethazine for a client, the nurse needs to use the formula D/H x V, where D is the desired dose, H is the available dose, and V is the available volume. In this case, D is 25 mg, H is 50 mg, and V is 1 mL. Plugging these values into the formula, we get: 25/50 x 1 = 0.5 mL Therefore, the nurse should administer 0.5 mL of promethazine 50 mg/mL IM to the client.