Interactions between chronic headache and analgesic drug overuse: clinical and toxicological aspects

Usually overuse of analgesic drugs in chronic headache sufferers is seen only as a secondary or accesssory event complicating headache. We instead believe that the two phenomena are closely interrelated, so to generate a "loop" from which important clinical and toxicologial implication can derive. On the basis of these considerations the aim of our research was to descrive the complex interactions between patient, chronic headache and analgesic drug. The combination of indomethacin plus caffeine plus prochlorperazine, and triptans were the medications most frequently overused by our patients; only a few patients overused ergot preparations. The majority of patients used the same type of drug daily. All patients referred they increased the frequency of self-medication because the headaches were getting worse. For most patients medication overuse made the headache more endurable, thus allowing them to work orfunction more or less normally in daily life. Only a minority experiencedwithdrawal symptoms after discontinuation of the medication overuse. After detoxification, antidepressants were the class of drugs most used for prophylaxis