Common

• Common side effects include marked drowsiness that will be increased if taken in combination with alcohol. It also causes vomiting and difficulty urinating, stomach pain, or a rash.
  
  

Allergies

• If you experience swelling anywhere on the body, fainting, or shortness of breath, you could be allergic to the medicine. If you are allergic to codeine you should not take levophanol.
  
  

Interactions

• You must tell your doctor if you are taking any other over-the-counter, herbal, or prescription pain relievers to avoid potentially dangerous interactions. If you are having surgery of any kind, you must tell the doctor you are taking this medication.
  
  

Severe

• If any of the side effects including, dizziness, headaches, stomach pain, or problems urinating do not subside or get worse, you need to seek medical attention.
  
  

Warning

• Take this medication only as prescribed. Tell your doctor if you taken this prescription other than as prescribed as it can be habit forming and may require medical assistance to quit taking it.