Shift workers can suffer from insomnia, excessive sleepiness or both, and may use various over-the-counter and prescription products to deal with these symptoms.
However, there is little evidence to support the efficacy of these drugs and some may have serious side effects, according to Juha Liira from the Finnish Institute of Occupational Health, Helsinki, and co-authors of an updated Cochrane review (online, 12 August 2014)
They found just 15 relevant trials involving 718 participants. There was low-quality evidence to support the efficacy of melatonin for improving sleep length and insufficient evidence relating to hypnotics (e.g., zopiclone). For increasing alertness, caffeine plus naps appears to work well, while modafinil and armodafinil are effective but have potentially serious adverse effects.
More trials and research of a higher quality is needed for all of these drugs, the researchers conclude.
 Liira J, Verbeek JH, Costa G et al. Pharmacological interventions for sleepiness and sleep disturbances caused by shift work. Cochrane Database of Systematic Reviews 2014 DOI: 10.1002/14651858.CD009776.pub2