Caffeine citrate (Cafcit) is a citrate salt of caffeine, sometimes used in medical treatment, including short-term treatment of apnea of prematurity (lack of breathing in premature infants). Caffeine citrate functions in much the same capacity as does caffeine, but takes effect more quickly; its speed of dissociation is faster than that of caffeine. Like its sister compound, it can be used to dispel pain from a headache. However, caffeine citrate is typically only used to treat severe migraines.
The drug is prepared simply by combining anhydrous caffeine with citric acid monohydrate and sodium citrate dihydrate. In method of action, the preparation is exactly identical to that of caffeine base as the citrate counter ion dissociates in water. Doses of caffeine citrate, due to the added weight of the citrate moiety, are understandably higher than with caffeine base, i.e., it takes a larger dose to get the same amount of caffeine. The ratio of therapeutic doses of caffeine base to its citrate salt is typically 1:2. It is therefore generally recommended that caffeine is prescribed in terms of caffeine base, and not caffeine citrate.