Codeine is a mild opioid (narcotic) pain killer, which has less of an addiction potential of butorphanol, described in the previous post, or most other opioid drugs. However, it definitely can cause addiction and can be a “gateway drug” leading to the abuse of stronger prescription and illicit drugs. Some countries allow codeine to be sold without a doctor’s prescription, but it is always in a combination with other drugs. In Canada, codeine has to be mixed with two other drugs, usually with acetaminophen and caffeine and it is sold without a prescription, but from behind the counter rather than from open shelves.
A combination of codeine with caffeine, butalbital and either acetaminophen or aspirin (Fioricet with codeine and Fiorinal with codeine) is particularly problematic because caffeine can also cause medication overuse headache and butalbital is also addictive.
The main problem with codeine is that just like other opioid drugs it is not very effective and can cause or worsen nausea. If taken regularly (more than once a week) opioids can also cause medication overuse (or rebound) headache even in the absence of addiction. Codeine with acetaminophen is worth considering if triptans (sumatriptan or Imitrex and similar drugs) and NSAIDs (Advil or ibuprofen, Aleve or naproxen, and other) are ineffective or contraindicated.
I do have patients taking Fioricet or Fiorinal with codeine or codeine with acetaminophen with good relief and few side effects, but I can count those patients on the fingers of one hand.
