When the FDA approved modafinil (Provigil) in 1999, night shift workers and international travelers lined up for prescriptions. Soon, reports came in that modafinil, while living up to its promise of increased alertness, caused side effects of irritability, edginess and weight loss, symptoms similar to those of amphetamine and related sympathomimetic amines. Suspicions of its potential for abuse were sparked early on. In addition to its effects on the psyche, modafinil was also found to rarely caused increased blood eosinophil counts, hypertension, and severe allergic reactions.

A new pilot study of ten subjects confirms that modafinil increases blood dopamine levels, changing brain chemistry in a way that can invite addiction. By increasing dopamine, users of Provigil can experience increased feelings of well being and more focused, despite feeling somewhat wired. These reasons have led to modafinil’s wide acceptance among college students and academics. It’s no wonder that sales of Provigil exceeded $850 million in 2008. As an approved treatment for narcolepsy, modafinil has the ability to keep narcolepsy sufferers awake throughout the day. Night shift workers who use the drug report being able to stay awake throughout the day after working all night when necessary. Students call it a smart drug because of its reported ability to improve attention span. Off label, modafinil has been used to treat attention deficit syndrome, depression, and lethargy. A longer-acting formulation of modafinil called armodafinil (Nuvigil), is scheduled for release in the third quarter of 2009.
As a night shift worker, I was one of the first to line up for a modafinil prescription when it first hit the market. The first time I tried it after working the graveyard shift, I was able to stay awake all day. The problem was that I was plagued by insomnia and couldn’t take a nap when the opportunity arose. For me, modafinil worked better as a remedy for staying alert at night on the days I got little sleep. Although I noticed feeling more irritable, I probably would have kept on using the drug had I not developed eosinophilia. Not realizing the cause, my eosinophil count rose to 28 percent, baffling my doctors until they noticed in the literature that eosinophilia was a rare, potentially serious, side effect. Normally, the eosinophil count rarely rises above 6 percent. The white blood cells known as eosinophils produce toxic granules that can cause serious adverse effects.
The new reports of modafinil’s potential for addiction aren’t surprising. Like other drugs of this class, modafinil has been suspected of having this potential since it was first developed. It’s the other side effects of modafinil that should be a cause for concern, particularly its effects on the immune system.