Cardiac arrhythmias, seizures, and delirium are possible after deliberate overdoses. Caffeine is a mild diuretic. Polyuria can occur. In 1992, a distinct caffeine withdrawal syndrome was described. Patients who consume or receive caffeine daily for several weeks experience notable physical and psychiatric responses including lethargy, anxiety, dizziness, or headache.
Caffeine occurs naturally in tea, coffee, cocoa, and chocolate, and is added to many soft drinks.
Generic forms of caffeine are available, and can be obtained without a prescription. Take caffeine tablets or caplets by mouth. Follow the directions on the prescription label. If you are taking an extended- release form of caffeine, swallow whole, do not crush or chew. If you are taking chewable tablets, chew well and swallow.