•Fast heartbeat, changes in heart's electrical activity
•Chest pain
•Diarrhea, constipation
•Skin rash
•Trouble emptying bladder
•Delayed ejaculation, less sexual power in men
•Thirst, chills, more sweating
RARE
•Thoughts of harming yourself or trying to do so
•Muscle pain, cramps, or weakness that cannot be explained; in very rare cases, severe muscle breakdown that can harm kidneys or lead to death
•Fewer blood platelets (makes you bleed more easily), swollen lymph glands
•Cold sores (oral herpes), athlete's foot
•Seeing or hearing things that are not there (hallucinations), confusion, depression, thinking strange thoughts (paranoia), not knowing where you are or what time it is, nightmares, feeling very restless, changes in sex drive, unusual dreams
•Shaking (tremor), feeling sleepy
•Blurry vision, irritated eyes, sensitive to light, swollen or painful eyes, eye strain
•Ear discomfort, ear pain, ringing in ears (tinnitus)
•Changes in blood pressure, flushing (red face and neck)
•Stuffy nose, uncomfortable feeling in nose, runny nose, sneezing, sore throat, more mucus, sinus problems, trouble breathing, changes in voice, cough, yawning
•Gas, hemorrhoids, sores (ulcers), dry mouth
•Liver problems, higher levels of bilirubin (a substance in the blood), liver inflammation
•Oily skin, itching, acne, hair loss, red skin rash
•Groin pain, needing to urinate often, painful or hard urination
•More appetite, losing or gaining weight, fever, general pain, cold hands and feet, feeling hot
•Feeling very happy (euphoria)
•Speech problems
Important Warnings
Do not take if you are allergic to naltrexone or any other ingredient in this medicine.
Do not take if you are using or have recently used opioid medicines (like strong painkillers) or are dependent on opioids.
Tell your doctor if you have severe liver disease, hepatitis (liver inflammation), or severe kidney disease.
Do not take this medicine with methadone.
If you use opioids while taking this medicine, or soon after stopping it, you could have a dangerous overdose or severe withdrawal.
Show 3 more warnings
Always tell your doctor or pharmacist about all other medicines you are taking, especially any that contain opioids, as they may not work as well.
If you are pregnant, planning to become pregnant, or breastfeeding, talk to your doctor or pharmacist before taking this medicine.
This medicine might make it harder to drive or use machines safely. Be careful until you know how it affects you.