Headaches
71. M.K., a 32-year-old man, is complaining of severe headaches that occur at least once every 2 weeks. He takes two Excedrin extra-strength tablets (acetaminophen 250 mg, aspirin 250 mg, and caffeine 65 mg) every 2 hours until the headache starts to ease and sometimes requires a cumulative dose of up to 16 tablets. Migraine and vascular headaches have been ruled out in M.K. Would one of the nonsalicylate NSAIDs be more efficacious for M.K.? Are there any other considerations in managing M.K.'s headache? Is caffeine an effective analgesic for headaches?
Headaches are common, afflicting nearly everyone at some time during their life. The incidence of headache is higher in females and increases with age; 10% of headaches develop into chronic disabling conditions. For M.K., who self-medicates chronically with large doses of acetaminophen, the concern is toxicity from the analgesics. Chronic use of both NSAID analgesics and caffeine (either as single agents or in combination) can possibly precipitate withdrawal (“rebound”) headaches on discontinuation. Although NSAIDs are not considered habituating, accumulating evidence indicates that chronic intake of peripheral-acting analgesics can perpetuate the underlying pain syndrome. In the case of M.K., it is important to consider the possibility of caffeine withdrawal headache as well, because he is taking a caffeine-containing combination product. Other dietary sources of caffeine ingestion from coffee, tea, and other foods should be determined as well.
Caffeine is used in analgesic combination products because it has both a CNS stimulant and a vasoconstrictive effect, which may reverse some of the headache symptoms. The value of caffeine, especially in the small quantities found in most pain relievers, has been controversial. A meta-analysis and subsequent study conclude, however, that caffeine does add to the analgesic effect of aspirin and acetaminophen.235,236
Acute headache can be managed with parenteral ketorolac, but it is not a viable alternative for chronic headache management.237 M.K.'s headaches may resolve on gradual withdrawal of NSAID analgesics and caffeine, but this process is slow and requires the clinician's as well as the patient's determination to stay with the treatment plan. (Also see Chapter 53, Headache.)
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