One of the most common sleep disorders is insomnia. When one has difficulty sleeping, staying asleep or waking too early and then not being able to go back to sleep are common symptoms of insomnia.

There are many causes and types of insomnia. One may suffer insomnia for a few nights due to stress (transient insomnia), or suffer insomnia for a few weeks, could be due to some illness (short-term insomnia) and insomnia that lasts for more than a month (chronic insomnia).

Chronic insomnia can decrease the ability to concentrate, cause memory loss and fatigue. Many studies also suggest that insomnia is associated with many serious medical conditions, and may increase the risk of developing certain psychiatric disorders, particularly depression and anxiety.

Sanofi launched Ambien in US in 1993. Since then it has been the top selling drug in this category. More than 26 million prescriptions for Ambien were dispensed in US last year, an increase of 53 percent since 2001.

Ambien is the brand name used in the United States for the drug Zolpidem. Ambien is sold in some countries under the brand names Stilnox and Stilnocht. Ambien is the biggest seller among a group of similar prescription sleeping pills that include Lunesta and Sonata.

Ambien drug is worth $2.2 billion in annual sales in the United States. This has largely been due to the aggressive advertising and marketing by Sanofi-Aventis. According to reports the pharma major spent $130 million to advertise the product in 2005, more than double the $61 million it spent in 2004.

Ambien is used as a short term treatment for insomnia. Ambien side effects are drowsiness, dizziness and diarrhea. Ambien when taken for the first time, caution should be taken while engaging in morning activities until one gets used to the medication.

Prescription sleep aids are often not taken for more than 7 to 10 days. It can be taken for longer periods too if advised by the doctor. All people taking sleep medicines have some risk of becoming dependent on the medicine

Ambien should be taken as advised by the doctor. It should be taken only before going to bed. Ambient should not be taken unless the patient is able to get a full night's sleep. Ambien should not be taken with alcohol.