Prescription drugs come in many forms. The prescription drugs most often misused include opioid painkillers, anti-anxiety medicines, sedatives and stimulants.

-Opioids

Constipation
Nausea
Feeling high
Slowed breathing rate
Drowsiness
Confusion
Poor coordination
Increased dose needed for pain relief
Worsening or increased sensitivity to pain with higher doses
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-Anti-anxiety medicines and sedatives

Drowsiness
Confusion
Unsteady walking
Slurred speech
Poor concentration
Dizziness
Problems with memory
Slowed breathing
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-Stimulants

Increased alertness
Feeling high
Irregular heartbeat
High blood pressure
High body temperature
Reduced appetite
Insomnia
Agitation
Anxiety
Paranoia
Other signs
Forging, stealing or selling prescriptions
Taking higher doses than prescribed
Being hostile or having mood swings
Sleeping less or more
Making poor decisions
Being unusually energetic, high or revved up
Being drowsy
Requesting early refills or continually "losing" prescriptions, so more prescriptions must be written
Trying to get prescriptions from more than one prescriber