Is Nyquil Addictive? Signs and Symptoms of Abuse

Authored by Granite Recovery Centers    Reviewed by James Gamache    Last Updated: August 27th, 2021

James Gamache Medical Reviewer
Jim is a Licensed Clinical Social Worker (LICSW) and Licensed Masters Level Addictions Counselor (MLADC). He has been working in the field of mental health/addiction treatment since 1995. Jim earned a Bachelor’s Degree in Human Services from Springfield College in 2000, and a Masters Degree in Social Work from Boston University in 2002. In 2002 Jim was hired by the Mental Health Center of Greater Manchester holding the position of Clinical Case Manager. From 2004-2019, Jim was employed at WestBridge Inc. During his time at WestBridge, Jim held the following positions; Clinician, Team Leader, Director, & Chief Operations Officer. In 2019 Jim transitioned employment to GateHouse Treatment Center as the Clinical Director for 10 months. In October of 2020 Jim transitioned to Granite Recovery Centers and is currently serving as the Senior VP of Clinical Services and Quality Assurance.

Nyquil is an over-the-counter drug used to treat symptoms caused by allergies, the common cold, the flu, and breathing illnesses like bronchitis and sinusitis. It contains three active ingredients:

  • Acetaminophen – A non-aspirin fever reducer and pain reliever
  • Dextromethorphan – A cough suppressant that alters part of the brain and thus reduces cough
  • Doxylamine succinate – An antihistamine that relieves runny nose, sneezing, itchy eyes, itchy throat and nose, and watery eyes

Do not use Nyquil to treat ongoing coughs from smoking, long-term breathing problems or asthma. It is also not effective on children younger than 6 years. Visit your doctor if you have a child with cold symptoms.

Like other over-the-counter drugs, continuous use of Nyquil may cause serious side effects, dependence and, in some cases, withdrawal symptoms. Follow dose instructions carefully to avoid these effects and symptoms.

How to Take Nyquil

Ensure that you read and follow all instructions on the packaging label. Use it as directed by your pharmacist or doctor. If you have any uncertainties, consult a professional first before you begin your dose.

Take Nyquil by mouth regardless of whether you have eaten or not. If you experience stomach upsets, make sure you take it with milk or food. Taking a lot of fluids is advisable because it helps loosen the mucus found in your lungs.

If you are taking Nyquil in liquid form, measure the dose using the given measuring spoon. Using a household spoon may increase your dosage. Shake the bottle before use. In the case of chewable tablets, chew them before you swallow.

Nyquil is also available as extended-release capsules. Swallow them whole. Do not crush them and then swallow because you can release all the dose at once. Consequently, this may increase the risk of severe side effects.

The dosage recommendation you get from your doctor is based on your response to treatment, age and medical condition. Avoid taking it more frequently, using it longer than prescribed or increasing your dose. Improper use may lead to abuse and harm like brain damage or seizure.

If your condition continues for more than one week or worsens, tell your doctor. You may be having an underlying medical condition.


One of the ingredients found in Nyquil is acetaminophen. If you consume too much acetaminophen, it can lead to liver disease. If you have liver problems, take only small amounts of acetaminophen. Children should also take fewer amounts. Consult with your doctor on how much acetaminophen you should take.

Do not combine Nyquil with other drugs unless under your doctor’s prescription. Since acetaminophen is found in many cough and cold medications, check all the labels on your medicine. If you find that it is present, ask your doctor or pharmacist for guidance.

Side Effects

Prolonged use of Nyquil can have adverse effects on your health. However, many people using this prescription do not experience serious side effects. Some of the side effects include:

  • Dizziness
  • Dry mouth, throat or nose
  • Blurred vision
  • Constipation
  • Upset stomach
  • Nervousness
  • Nausea

Doctors recommend this medication if they feel that the benefits outweigh the risks of side effects. If you experience the above side effects, consult with your doctor. They will adjust your dose accordingly.

In some cases, you may experience the following more serious side effects:

  • Trouble urinating
  • Shaking
  • Mood changes
  • Confusion
  • Hallucinations
  • Irregular heartbeat
  • Seizure

Tell your doctor so that they may take appropriate action. Some patients report significant allergic reactions when they take Nyquil. However, it is rare. Seek medical attention if you experience allergic reactions like:

  • Breathing trouble
  • Rashes
  • Swelling or itching of the throat, tongue or face
  • Severe dizziness

The following are some precautions you should take concerning this medication:

  • If you have existing health problems, inform your doctor before taking Nyquil. Health problems like high blood pressure, seizures, kidney problems, overactive thyroid, asthma, diabetes, heart problems, glaucoma and constipation may lead to serious side effects.
  • Do not take Nyquil if you have any form of allergies. Nyquil contains inactive ingredients that can lead to allergic reactions. Consult your doctor for more information.
  • Nyquil contains ingredients that contain aspartame, alcohol or sugar. If you have liver disease, phenylketonuria, alcohol dependence, diabetes or a condition that requires you to limit the use of these substances, proceed with caution and seek your doctor’s advice.
  • Older individuals tend to be more sensitive to Nyquil’s side effects. Low blood pressure, constipation, dizziness and drowsiness increase the chances of falling.
  • Before getting into surgery, tell your doctor that you are using Nyquil.
  • Nyquil use may cause blurred vision and drowsiness. Do not drive, operate machinery or engage in something that requires alertness if you experience these side effects. Avoid alcohol at all costs. Seek the guidance of your doctor if you are using marijuana.
  • Nyquil can pass into breast milk and lead to undesirable effects in an infant, so talk to your doctor before breastfeeding.

Interaction With Other Drugs

Drug interaction can alter how your prescription works, and in some cases, it may increase the risk of significant side effects. Ensure that you record all your medications and show them to your doctor when acquiring a Nyquil prescription. Do not stop or change the dosage without your doctor’s approval.

Some MAO inhibitors lead to serious drug interaction when taken alongside Nyquil. They include:

  • Methylene blue
  • Selegiline
  • Isocarboxazid
  • Moclobemide
  • Procarbazine
  • Safinamide
  • Phenelzine
  • Rasagiline
  • Tranylcypromine

Do not take these MAO inhibitors for two weeks before your Nyquil prescription. Follow your doctor’s directives.

Some other products that may cause interaction include:

  • Alcohol
  • Marijuana
  • Sleeping and anxiety drugs such as zolpidem and lorazepam
  • Muscle relaxants like carisoprodol and cyclobenzaprine
  • Antihistamines like cetirizine and diphenhydramine
  • Opioids like codeine and hydrocodone
  • Ketoconazole
  • Rolapitant

Nyquil contains medications found in other products, so using such products alongside Nyquil may increase the overall side effects. Check all medication labels before using them and seek the intervention of your pharmacist.

Nyquil may also interfere with your lab tests, leading to false results. Before undertaking a lab test, make sure your doctor knows that you use Nyquil.

Nyquil Signs and Symptoms of Abuse

The consistent use of Nyquil over a long period may lead to dependency and addiction, especially if you are using it contrary to your doctor’s advice. Addiction cases may result when you use any drug more often than is recommended to achieve the desired effect.

Recommended Daily Dose

Take Nyquil as directed by your pharmacist or doctor only. Do not take more than four doses per day. For adults and children over 12 years, take one dose alongside water after every six hours. For children under 12 years, ask your doctor. Do not give this medication to children under 4 years old. Read each label to guarantee correct dosing.

Signs and Symptoms of Abuse

When this medication is used alone, the chances of getting Nyquil addiction are low. However, when combined with other drugs such as alcohol and marijuana, you may experience dangerous health complications such as:

  • Confusion
  • High blood pressure
  • Impaired motor control
  • Seizures
  • Hallucinations

Individuals who have Nyquil use disorder can develop liver and kidney damage. In some cases, they also experience memory problems. By the time you realize that you are addicted to Nyquil, it may be much more difficult to quit using it. The sudden stop of Nyquil use might lead to significant withdrawal symptoms, so before stopping, seek the advice of your doctor.

Withdrawal symptoms occur within a few hours after stopping, and they peak within three days. Some common Nyquil withdrawal symptoms include:

  • Insomnia
  • Seizures
  • Restlessness
  • Tremors
  • Vomiting and stomach cramps
  • Cold flashes
  • Weight loss
  • Depression
  • Anxiety
  • Cravings

The severity of these withdrawal symptoms depends on:

  • Metabolism, weight and age of the user
  • Duration of abuse
  • Amount of dosage an individual takes
  • Mental and physical health
  • Whether the individual uses Nyquil with other drugs

The good news is that Nyquil addiction is treatable if you follow all the recommended detox procedures. Professionals at a reliable rehabilitation center can help you with the next steps.


There is always a risk of an overdose when you use Nyquil other than prescribed by your doctor. The following symptoms are predominant in an individual who has overdosed:

  • Nausea
  • Seizures
  • Vomiting
  • Dark urine
  • Loss of appetite
  • Yellowing eyes or skin
  • Sweating
  • Hallucinations
  • Abdominal pain
  • Flushing
  • Extreme tiredness
  • Confusion
  • Agitation

Children may be excited at first, followed by loss of consciousness, drowsiness, seizures and coordination loss. If you come across an individual who has overdosed, call 911 or a poison control center fast.

Often, addiction leads to an overdose, knowingly or unknowingly. To prevent future cases of Nyquil overdose and other health complications, seek medical rehabilitation to help you quit using the drug. A rehabilitation facility like Granite Recovery Centers can guide you on your road to recovery.

Granite Recovery Centers

Your recovery journey starts at Granite Recovery Centers. We are a renowned rehabilitation facility, having worked in this sector for over a decade. We endeavor to transform the lives of adults with substance use disorders, including abuse of Nyquil.

We have a full continuum of care featuring primary residential treatment, sober living, medical detox, intensive outpatient counseling, extended care and much more. Our active and growing alumni community is evidence of our success, so you can trust us with your health. Granite Recovery Centers provides medical detoxification for people who do not need immediate medical intervention, are not a danger to themselves, and are capable of self-evacuation in the event of an emergency.

Here is a recap of our services:

  • Inpatient drug rehab – Our inpatient drug rehab centers offer intensive, round-the-clock monitored support in helping you get sober. We help you gain appropriate skills and insights to maintain your long-term sobriety. We have residential detox programs at Green Mountain Treatment Center, Granite House and New Freedom Academy, all in New Hampshire. Our caring medical staff can ease your withdrawal symptoms and motivate you to continue rehabilitation with therapy.
  • NFA Behavioral Health – Our counselors will use cognitive behavior therapy to help you overcome addiction. We offer clinical psychotherapeutic support that features process groups, motivational interviewing, grief and loss therapy, one-on-one individual therapy, dialectal behavior therapy and co-occurring mental disorders treatment. In addition, we provide nutritious meals at our gender-separate living accommodations.
  • Intensive outpatient program – Green Mountain Treatment Center offers a serene, secluded environment that allows our patients to live with their peers in scenic surroundings. We incorporate individualized treatment plans, a 12-step-centered curriculum, medical detox, clinical modalities and holistic therapies. You also get to enjoy an on-site gym, transport services, meditation and yoga, workshops and education programs, and gender-separate programs.
  • Sober living homes – These homes offer early recovery programs with ongoing support from our professionals. You get to interact with your peers as you all seek to enjoy a successful recovery journey.
  • Alumni program – After your recovery process, you get the unique opportunity to join our ever-growing alumni community. Regular meetings let you share your experiences with your peers and also engage in motivational programs. You are part of our tribe.

Granite Recovery Centers provides drug rehabilitation programs to help individuals who want to leave substance abuse and dependence behind them. Seek our services today if you need help to overcome substance use disorder. The journey may be difficult, but it is worth the effort.


Although it is rare to become addicted to Nyquil, there is always a chance when you use it with other drugs like alcohol or marijuana. Do not take Nyquil other than prescribed by your pharmacist or doctor. If you endure significant withdrawal symptoms after stopping its use, seek the intervention of your doctor.

At Granite Recovery Centers, we want to provide accurate information about health and addiction so that our readers can make informed decisions.

We have credentialed medical doctors & clinicians who specialize in addiction treatment review the information on our website before it is published. We use credible sources such as government websites and journal articles when citing statistics or other medically related topics.