Headaches and Nausea

• For some people, the common complaint of a side effect is the feeling of being light-headed or extreme dizziness, usually accompanied by a feeling of being nauseated.
  
  

Extreme Fatigue

• Some who take butalbital complain of feeling intoxicated or sedated and may feel extremely drowsy or fatigued after taking this medicine. Because butalbital causes drowsiness patients are instructed to consult a physician about possible drug interactions with medications that cause drowsiness such as sleeping medications, anti-anxiety drugs, psychiatric medications, muscle relaxers and tranquilizers.
  
  

Addiction

• Butalbital is an addictive medication, and in some cases the user may experience a form of euphoria after using the drug, which may account for the addiction.
  
  

Impaired Judgment

• One of the main side effects of butalbital is a severe impairment of judgment. Use of alcohol and other drugs have been known to mix with this drug to cause accidental death.
  
  

Gastrointestinal Problems

• Some people have also had complaints about gastrointestinal problems such as diarrhea and constipation.
  
  

Allergic Reactions

• Allergic reactions are another complaint of this medication, although this is rare, and may include itching, breathing problems and extreme facial swelling.