A 64‐year‐old man with narcolepsy could not take stimulant drugs due to coronary heart disease. In the past he noted improvement in alertness when taking codeine for pain, but this was eventually discontinued. After he developed end‐stage renal disease, and because the use of stimulants in this setting may be difficult, treatment with codeine was again initiated. This resulted in dramatic improvement in alertness and substantial reduction of cataplexy. Because it is simple to use and familiar to most physicians, codeine may be the drug of choice for narcoleptic patients who are undergoing hemodialysis.