Results Three states (California, Oregon, and Washington) had medical cannabis laws effective prior to 1999. Ten states (Alaska, Colorado, Hawaii, Maine, Michigan, Montana, Nevada, New Mexico, Rhode Island, and Vermont) enacted medical cannabis laws between 1999 and 2010. States with medical cannabis laws had a % lower mean annual opioid overdose mortality rate (95% CI, −% to −%; P = .003) compared with states without medical cannabis laws. Examination of the association between medical cannabis laws and opioid analgesic overdose mortality in each year after implementation of the law showed that such laws were associated with a lower rate of overdose mortality that generally strengthened over time: year 1 (−%; 95% CI, −% to −%; P = .002), year 2 (−%; 95% CI, −% to −%; P = .01), year 3 (−%; 95% CI, −% to −%; P = .04), year 4 (−%; 95% CI, −% to −%; P = .02), year 5 (−%; 95% CI, −% to −%; P = .008), and year 6 (−%; 95% CI, −% to −%; P < .001). In secondary analyses, the findings remained similar.
Topical analgesia is generally recommended to avoid systemic side-effects. Painful joints, for example, may be treated with an ibuprofen - or diclofenac -containing gel (The labeling for topical diclofenac has been updated to warn about drug-induced hepatotoxicity.  ); capsaicin also is used topically . Lidocaine , an anesthetic , and steroids may be injected into painful joints for longer-term pain relief. Lidocaine is also used for painful mouth sores and to numb areas for dental work and minor medical procedures. In February 2007 the FDA notified consumers and healthcare professionals of the potential hazards of topical anesthetics entering the blood stream when applied in large doses to the skin without medical supervision. These topical anesthetics contain anesthetic drugs such as lidocaine, tetracaine, benzocaine, and prilocaine in a cream, ointment, or gel.