Sleeping pills. Collection of Zimonvane sleeping pills. Zimovane contains the drug zopiclone & is prescribed for short-term treatment of insomnia, a patient's inability to fall asleep, or sleep long enough. Insomnia has many possible causes, including environmental factors such as noise and light, too much caffeine, lack of exercise, anxiety, depression and various psychiatric illnesses. Zopiclone promotes sleep by reducing the activity of nerve cells within the brain. Side effects include nausea, dizziness, depression and drowsiness the next day. Long-term use of sleeping pills can lead to tolerance and dependence.