Norco Side Effects

All drugs, including Norco, have the potential to cause side effects. Many people experience no, or minor, side effects while taking Norco. Most adverse are not serious and decrease in severity or disappear completely after using Norco as directed for a few days. Some side effects are serious and require the attention of a doctor.

The side effects associated with Norco are typical of any opioids. The most serious side effect is respiratory problems potentially leading to stopped breathing, circulation problems, severely low blood pressure and shock.

Side effects are more likely after using high doses of Norco or using this drug for a long time.

Whenever you take any opioid including Norco, you are at risk for the serious breathing condition, respiratory depression. During respiratory depression, your lungs do not adequately exchange oxygen, carbon dioxide and other blood gases. Symptoms of respiratory depression include slow or shallow breathing, unusual breathing patterns, gasping or wheezing, and a bluish tint around your eyes, mouth and fingertips.

Most Frequently Observed Side Effects

The most frequently observed Norco side effects include lightheadedness, dizziness, sedation, nausea and vomiting. People who are able to walk around are more likely to experience these side effects than is someone confined to a bed or wheelchair. If you experience any of these symptoms, lie down for a while.

Non-Serious Side Effects

The most common side effects associated with this medication are not serious and disappear after taking this drug for a few days. Continue taking this medication but contact the prescribing physician if the following side effects become intolerable or if they do not go away on their own:

  • Anxiety
  • Blurred Vision
  • Constipation
  • Dizziness
  • Drowsiness
  • Dry Mouth
  • Headache
  • Mild Nausea
  • Mood Changes
  • Ringing in Your Ears
  • Upset Stomach
  • Vomiting

Serious Side Effects

Some side effects are serious, requiring immediate medical attention. Stop taking Norco immediately and contact a doctor if you experience serious side effects, including:

  • Clay-Colored Stools
  • Confusion
  • Dark Urine
  • Fainting
  • Fear
  • Feeling Light-Headed
  • Itching
  • Loss Of Appetite
  • Nausea
  • Problems With Urination
  • Seizure
  • Shallow Breathing
  • Slow Heartbeat
  • Unusual Thoughts Or Behavior
  • Upper Stomach Pain
  • Yellowing of the Skin or Eyes

Abuse, Dependence and Withdrawal

Potential for abuse, physical dependence or addiction are possible side effects associated with Norco. The U.S. Drug Enforcement Agency, or DEA, classifies substances according to the potential for abuse. The DEA has classified Norco as a Schedule II narcotic, which means it carries a high potential for abuse and mental or physical dependence.

Anyone who uses Norco for a long time can become dependent upon it. An opioid-dependent person will feel withdrawal symptoms if the level of opioids suddenly drops. This drop can be caused by a missed dose, insufficient dose or because the person used a medicine that reduces opioid levels. Withdrawal symptoms include:

  • Abdominal Cramps
  • Agitation
  • Anxiety
  • Blurred Vision
  • Insomnia
  • Restlessness
  • Sweating
  • Tremor
  • Vomiting

Allergic Reaction

You may suffer an allergic reaction after taking Norco or any other medication. If you suffer an allergic reaction after taking Norco, seek help immediately - an allergic reaction is a serious medical emergency. Bring your bottle of Norco along with all your medications to help the emergency department doctor understand which medication caused the reactions.

Symptoms of an allergic reaction include:

  • Difficulty Breathing
  • Hives
  • Itching
  • Rash
  • Swelling of the Mouth, Face, Lips or Tongue
  • Tightness in the Chest


Rarely, patients have reported hypersensitivity to the acetaminophen in Norco. Hypersensitivity may lead to shock or anaphylaxis, a severe form of an allergic reaction. Anaphylaxis usually occurs within moments of exposure to Norco but may happen as long as a half an hour or longer after you take this medication. Seek help immediately if you think you or someone you know is suffering anaphylaxis.

Symptoms of anaphylaxis include hives, itching, flushed or pale skin. You might have a sensation of warmth. You might also feel like your tongue is swelling up, you have a lump in your throat, or that your throat is closing. These problems can lead to wheezing and trouble breathing. You might have a weak and rapid pulse, nausea, vomiting, dizziness or fainting. You may have a terrible feeling of impending doom.

By body system


The side effects associated with the hydrocodone in Norco are similar to other opioids. People generally tolerate the acetaminophen component of Norco well when used in therapeutic doses.

The morphine sulfate in Norco works primarily in the central nervous system, or CNS, to relieve pain and cause euphoria, so many of the side effects associated with Norco involve the nervous system. However, Norco also causes side effects in other body systems.

Nervous system

Norco works directly on the part of the brain responsible for breathing, increasing the risk for respiratory depression, which can be fatal. Doctors treat respiratory depression with naloxone.

Nervous system side effects associated with hydrocodone include mental depression, dizziness, lightheadedness, stupor, delirium, excessive sleepiness, agitation and feelings of sadness.

Acetaminophen is not associated with nervous system side effects.


You may become dependent on Norco and experience withdrawal symptoms if you take this medication for a long time and suddenly stop. Physical withdrawal symptoms can last five or more days; psychological symptoms can last much longer, especially if left untreated or undertreated.


Alcoholic patients may develop liver damage after even modest doses of acetaminophen, like those in Norco.

Acetaminophen overdose may result in temporary liver damage.

Side effects associated with hydrocodone may be more likely and more severe in individuals with liver disease.

Alcoholic patients may experience hepatic side effects including severe and sometimes fatal dose dependent hepatitis. Liver damage is worsened by fasting. Several people have suffered liver damage after receiving long-term acetaminophen therapy, even though they lacked other risk factors for toxicity.


Gastrointestinal side effects associated with the acetaminophen component of Norco are rare except in alcoholics and after overdose. Rarely, patients have suffered acute pancreatitis after using acetaminophen like that in Norco.

Acetaminophen may cause acute biliary pain, affecting the liver, gall bladder and ducts connecting the two organs.

Gastrointestinal side effect including nausea, vomiting, constipation, and dry mouth are relatively common effects of all opioids including Norco.


Norco consumers may experience genitourinary side effects including spasms and urinary retention.


Norco users may suffer dermatologic side effects including narcotic-induced rashes.


Acetaminophen rarely affects the kidneys. Adverse renal effects are most often observed after overdose, from chronic abuse often with multiple analgesics, or in association with acetaminophen-related liver damage.

The adverse effects of the hydrocodone component of Norco may be more likely and more severe in patients with kidney problems.


The acetaminophen in Norco may rarely cause bleeding problems including clotting disorders.


Hypersensitivity side effects to acetaminophen are rare.


Norco and other opioids may cause respiratory depression.


Norco may cause rarely metabolic acidosis, a condition of too much acid in the system. Metabolic acidosis is more common after massive overdose of acetaminophen, often as the result of taking several products containing acetaminophen.