Smoked medicinal cannabis for neuropathic pain in HIV

It was reportedly effective when used in addition to pain treatment in patients with medically refractory pain due to HIV.

But as Paul Harvey said, “Now, the rest of the story.”

First, the details.

• 34 HIV patients with unresponsive neuropathic pain (pain that originates in the nerve, usually due to injury or disease) were recruited.
• Pain treatment was continued and they were assigned to both of the following treatments in random order.
  • Placebo
  • Active cannabis (1% to 8% Delta-9-tetrahydrocannabinol) 4 times daily for 5 consecutive days.
• The cannabis dose was increased by nurses based on pain response and side effects.
• Changes in pain intensity as measured by the Descriptor Differential Scale (DDS) was compared before the study to the end of each treatment.
• The patients smoked under direct observation in a hospital setting.
• Neither the patients nor researchers knew the treatment given — double-blind.
  • More about this later.

And, the results.

• 28 patients completed both treatments.
• Among those who completed the study, pain relief was significantly greater with cannabis.
  • 46% achieved at least 30% greater pain relief with cannabis vs 18% with placebo.
• Mood and daily functioning improved to a similar extent during both treatment periods.
• Side effects were mild and self-limited, but 2 participants experienced treatment-limiting toxicities.
  • Cannabis-related psychosis
  • Intractable coughing during cannabis treatment

The bottom line?
Any reduction in neuropathic pain is worthwhile, but it’s unfortunate that there was no difference in mood nor improvement in daily functioning between the cannabis and placebo treatments.

And it must be considered that the benefits came at the expense of significant side effects in about 7% of users.

There’s lots to criticize about the study design, which make the results suspect.

Most importantly, how does one go about concealing from patients that they’re smoking marijuana? In this study the participants were asked to “guess” which treatment that received. And 92% guess correctly by the second treatment. So, it’s really not a double-blind study as stated in the article.

Also, the results are based on those who completed the study not the original “intent-to-treat” population. Results based on all those recruited is preferred.

Another flawed study designed to advance the use of marijuana to treat neuropathic pain was published less than

3/31/09 19:24 JR