Tranquilizers can help reduce painful muscle tension and assist with sleep, and generally, they have been found to be helpful in fibromyalgia. However, they can be addictive if used for long periods of time. Use of tranquilizers should be carefully monitored by your physician. These drugs act on the brain thalamus and hypothalamus and exert a calming effect. Generally, tranquilizers are not used in fibromyalgia. Occasionally, a sedative like zolpidem tartrate (Ambien) may be prescribed if sleep is the major problem and other approaches to sleep management have not helped.
(Source: Your Personal Guide to Living Well with Fibromyalgia – An Official Publication of the Arthritis Foundation.)