ABSTRACT
Introduction 175
Antinociceptive Properties of Caffeine 175
Efficacy of Caffeine in the Treatment of Tension-Type Headaches 176
Efficacy of Caffeine in the Treatment of Migraine Headaches 177
Caffeine Withdrawal Headaches 178
Vascular Changes during Various Types of Headaches 178
Cerebral Vasoconstrictive Properties of Caffeine 179
Conclusion 179
References 180
INTRODUCTION
Caffeine is the most widely used psychoactive substance in the world. Most of the caffeine consumed comes from dietary sources such as coffee, tea, cola drinks, and chocolate. The consumption of caffeine is most often correlated with the positive effects following its ingestion, namely increased alertness, energy, and ability to concentrate (Benowitz, 1990; Fredholm et al., 1999; Nawrot et al., 2003). In addition to its dietary use, caffeine can also be found in a number of medications, mainly in over-the-counter and prescription preparations for weight loss and pain relief. The use of caffeine as an adjunctive constituent of analgesic medications can be dated back to 1875 when caffeine was first isolated and characterized structurally (Arnaud, 1987). The first clinical trials concerning the possible contribution of caffeine to the analgesic properties of aspirin and acetaminophen were only performed at the beginning of the second part of the 20th century. However, the interpretation of these studies is rendered difficult by their methodological limitations (Beaver, 1966, 1981).
