Some of the most popular sleep medications available by prescription today are the “Z-Drugs” (the non-benzodiazapines). It appears as though these are now the "go-to" drugs for doctors when confronted with an insomnia issue:
The Z drugs are a slightly different (molecularly) version of the popular benzodiapines – with trade names like Xanax, Zoloft, Ativan, Halcion, Valium and dozens of others. The Z-drugs and the "benzos" (as they’re often called) act basically the same way on the same receptors in your brain.
The Big Difference Between Z-Drugs and Benzos
As we said. the Z-Drugs are molecularly different than the benzodiazapines, but they both act on your brain’s GABAA receptors. The Z drugs are just more selective in their targeting of certain GABAA receptors.
In a nutshell, there are four specific areas of your brain where benzodiazapine type drugs act. They have been given specific names, and we know how they act:
alpha 1 – the hypnotic and anticonvulsant action
alpha 2 – primarily muscle relaxation, but some anxiety and anticonvulsant action too
alpha 3 – anxiety and anticonvulsant actions
alpha 5 – memory/amnesia actions (makes you forget you were awake)
The Drugs Act on Different Parts
The old style benzodiazapines (Xanax, Valium et al) act on all four receptors about the same. That's why they have all these side effects if taken only for sleep.
Zopiclone and Eszopiclone (Imovane and Lunesta) act on all the benzodiazapine receptors (alpha 1,2,3,5) as well - so except for their slightly shorter half-life, they basically act the same. That's why you'll not see them used all that often for sleep.
Zaleplon and Zolpidem (Sonata and Ambien) have a high affinity for the alpha-1 receptor (hypnotic), a low/moderate affinity for the alpha 2/3 receptors (muscle relaxation and anxiety) and almost no affinity for the alpha-5 receptor (memory/amnesia). This is the reason that the two drugs are now the most frequently prescribed sleeping meds - they promote the hypnotic effect, and not much else.
Withdrawal From the Z Drugs
Withdrawal from the Z Drugs is something your doctor will probably never bring up with you - but it's a big deal!
These drugs have another major difference with the old benzos in that they have a very short half life (the time it takes to eliminate them from your body).
While benzodiazapines can half half lives of 2-200 hours (depending on the specific drug), the Z Drugs have a range of 2-6 hours - with Sonata and Ambien leading the pack with a 2 hour half life (note that only one benzodiazaine - Halcion, has a 2 hour half life).
So this means that, if you're taking Ambien or Sonata, you could be withdrawing from the drug every day!
The withdrawal symptoms could include anxiety, muscle spasms, nausea, headaches, and other symptoms very similar to benzo withdrawal.
The way to withdraw from a Z-Drug, then, is the same way you would withdraw from a benzodiazapine.
The switching to diazepam (Valium) is recommended because it has a long half life (up to 100 hours), and it's easy to taper to a progressively smaller dose.
And that's how it's done ... you switch to a longer acting (but similar) drug and slowly (weeks and months, not days) reduce the dose until you're down to a small amount a couple of times a week. Then you go to zero drug, hopefully with zero side effects.