NyQuil Side Effects

by on March 11, 2012


NyQuil is an over the counter medication and is typically safe for most people to use. However, some side effects of NyQuil, both serious and common, have been experienced. Most commonly, patients will experience drowsiness, dizziness, or loss of appetite. Information about these side effects and an explanation of what to look for and when to see a doctor is discussed below.

Common NyQuil Side Effects

NyQuil is an over the counter medication, so it is relatively safe for all people to use, as long as it is taken correctly and directions are followed. However, some patients do experience side effects when taking this medication. Some of the common side effects include:

  • Drowsiness in the morning (next day)
  • Dizziness
  • Loss of appetite
  • Nausea
  • Stomach pain
  • Vomiting
  • Strange, Disturbing or very vivid dreams and nightmares

nyquil Although these symptoms are not considered to be serious, patients should consult with their physician if they worsen or do not go away.

Serious NyQuil Side Effects

Some of the most frequently experienced serious side effects of NyQuil are due to an allergic reaction. If this occurs, it is important to seek medical attention immediately. Some of the most common serious side effects include:

  • Rash
  • Swelling of the skin
  • Hives
  • Swelling of the tongue, lips, face, and mouth
  • Tightness in the chest
  • Difficulty breathing

NyQuil and Treatment of Other Diseases

There are several diseases that are thought to have negative reactions when a person takes NyQuil. Some of these include:

  • Renal or liver disease
  • Gastrointestinal narrowing
  • Diabetes
  • Glaucoma
  • Asthma or COPD
  • Heart disease
  • Anticholinergic effects

Acetaminophen, which is one of the main ingredients in Nyquil, is primarily metabolized within the liver to inactive forms. However, small amounts are converted to metabolites by minor pathways, and this can cause hepatotoxicity. Patients with hepatic impairments can be at increased risk of toxicity due to increased activity in the minor metabolic pathways. Severe liver injury, including cases resulting in liver transplant or death due to acute liver failure, has been reported in some patients that have used acetaminophen.

Pregnant women and new mothers that are breast feeding should consult with their doctors before taking Nyquil. Breast feeding is not recommended while taking Nyquil, as there has not been research conducted on whether the chemicals found in the medication can be transferred to a baby through breast milk. A woman’s physician should be able to assist her in weighing the risks and benefits of taking NyQuil while pregnant.

NyQuil is a relatively safe over the counter medication that provides relief from symptoms of the common cold or flu. Although this medication cannot cure these conditions or speed up the recovery process, it can help to make them more livable. Despite its over the counter status, some side effects, both common and serious, may be experienced. It is especially important for patients to consult their doctor if they are taking another medication or have a pre-existing medical condition before they begin treating their symptoms with NyQuil or any other medication.