Central nervous system

• Drowsiness
• Disorientation
• Delirium

Cardiovascular & Respiratory

• Bradycardia
• Hypotension
• Hypoventilation
• Shallow breathing
• Respiratory depression

Eyes, Ears, mouth, and nose

• Dry mouth (Xerostomia)
• Miosis, or pupil constriction (”pinpoint pupils”)

Gastrointestinal

• Nausea
• Vomiting (protracted)
• Constipation
• Dyspepsia

Urinary System

• Urinary retention

Musculoskeletal

• Analgesia
• Ataxia
• Muscle spasticity

Neurological

• Analgesia
• Physical dependence

Psychological

• Anxiolysis
• Confusion
• Euphoria
• Psychological dependence
• Somnolence

Skin

• Itching
• Flushing/Rash