Unisom as a single drug (not part of a combination) is used as a short-term treatment for sleep problems (insomnia).
Take this medicine with food or milk if it upsets your stomach.
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat. Call your doctor at once if you have any of these serious side effects: 
Dizziness; drowsiness; dry mouth, throat, and nose; thickening of mucus in nose or throat. Seek medical attention right away if any of these SEVERE side effects occur: Severe allergic reactions (rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); convulsions; decreased alertness; excitability; fast heartbeat; hallucinations; tightness or pounding in the chest; tremor; wheezing. 
Seek medical attention right away if any of these SEVERE side effects occur: 
Severe allergic reactions (rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); convulsions; decreased alertness; excitability; fast heartbeat; hallucinations; tightness or pounding in the chest; tremor; wheezing. 
If you miss a dose, take it as soon as you remember. It is better to take Unisom only when you can devote several hours to sleep. If it is almost your normal waking hour, skip the missed dose and wait until you are ready for bed again. Do not take extra medicine to make up the missed dose. 
Store Unisom at room temperature away from moisture and heat.