The Effects of Painkiller Use

Table of Contents

A painkiller can be any one of a number of drugs, from over-the-counter (OTC) medications like Tylenol, ibuprofen, and aspirin, to prescribed drugs like oxycodone, codeine, morphine, Vicodin, and hydrocodone. All painkillers carry risks—even OTC medications—but the tolerance and dependence that can develop with opioid painkillers—which have the potential to be highly addictive—may lead to misuse and even death.1,2,3

Heroin and painkiller infographic
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The Food and Drug Administration (FDA) regulates painkillers, also known as analgesics.10 Certain analgesics, including opioid analgesics, act on the central nervous systems to block or decrease pain sensitivity.10 Others inhibit the formation of certain chemicals in the body.10 The three main painkillers are acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs)—which are available as OTC pain relievers—and opioids—which are prescription only.10,11

Painkillers Effects question 1

Painkiller Characteristics

Acetaminophen is found in over 600 OTC and prescription medicines.10,11 It helps with all types of pain—including headache, muscle aches, sore throats, and fever—and is often used for mild to moderate pain.11 Acetaminophen poses a threat to those who drink more than 3 drinks per day or have liver disease.11,13 Side effects may include rash, hives, swelling of the body, and difficulty breathing or swallowing.13 NSAIDs include aspirin, naproxen, and ibuprofen.11,12 They are commonly used for the treatment of chronic health problems—including arthritis and lupus—as they can decrease inflammation, as well as reduce fever.12 Long-term use of certain NSAIDs can lead to side effects including stomach problems, kidney problems, high blood pressure, fluid retention, and other allergic reactions.11,12Opioids (also known as narcotics) treat moderate to severe pain and must be prescribed by a doctor.11 They pose a danger when mixed with alcohol or certain other drugs.11 Opioids pose a high risk of being habit forming.11

Painkillers Effects question 2

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Are Painkillers Harmful?

Painkillers can be harmful, especially when taken incorrectly. Overdose, either intentional or accidental, poses a very real risk when taking any OTC or prescription pain medication.

Taking a higher dose than recommended of acetaminophen can be dangerous and lead to acetaminophen toxicity, which can lead to liver damage and even death.10 Approximately half of the 56,000 emergency room visits and 500 deaths that occur each year due to acetaminophen overdose are unintentional.14 With NSAIDs, too much can lead to stomach bleeding and kidney damage.10

But it is opioids that pose the largest threat. In the United States, more than 130 people die every day from opioid overdose.4 In 2017, 1.7 million people suffered from substance use disorders (SUDs) related to prescription opioid painkillers.4 Misuse of and addiction to opioids has become a national crisis that effects the country in terms of health as well as social and economic welfare.4

Because of their reinforcing properties, even consistent prescription use of opioids can lead to significant tolerance and physical dependence, leading to higher and higher doses required to achieve pain reduction.

Opioid painkillers remain a front-line defense against pain, and this means they're routinely prescribed after major surgeries.2,5 They may also be prescribed for severe pain from certain health conditions like cancer and for chronic pain.5 Because of their reinforcing properties, even consistent prescription use of opioids can lead to significant tolerance and physical dependence, leading to higher and higher doses required to achieve pain reduction. This lays the groundwork for misuse of and addiction to the drug.

Painkillers Effects question 3

Opioid Short-Term Effects

Many painkillers that are typically abused fall under the opioid category. The effects are broadly the same and, in addition to reducing pain, opioids also activate the body’s reward system by  increasing dopamine activity, which may make users feel relaxed, happy, or high.3 Opioids can also impact the user’s ability to breathe when taken at a high dose.3

Painkillers Effects question 4

Opioid Side Effects


Because opioids and their analogs interact at the various opioid receptors in the brain, they have a wide range of side effects.

Possible side effects connected to the use of opioid painkillers include the following:2

    • Drowsiness.
    • Mental fog.
    • Nausea.
    • Constipation.
    • Dizziness.
    • Respiratory depression.

Opioids affect the part of the brain responsible for breathing, and one of the big threats opioid painkillers pose is the risk of slowed or restricted breathing. 2,5 When opioids are taken in high doses, a possible overdose can lead to the slowing or stopping of breathing—and even death.5

Painkillers Effects question 5

Opioid Dependence, Addiction, and Abuse

With continued use, people may develop tolerance to opioids. Tolerance is when a person must increase the number and size of doses in order to achieve the same effects as experienced previously.3,8

Higher and more frequent doses of opioid painkillers increases the risk of developing physiological dependence. This means that a person’s body has adjusted to the presence of the drug so well that it starts to need it in order to feel normal. When a person dependent on a drug stops taking it, they will experience withdrawal symptoms.2,9

Addiction is a chronic brain disease the causes people to compulsively seek and use drugs—despite harmful consequences.3,9 It is distinguished by the user’s inability to stop using the drug and failure to meet responsibilities.9

Tolerance, dependence, and addiction can cooccur independently or simultaneously. With all three, there is a risk of experiencing withdrawal symptoms when opioid use is stopped. Withdrawal symptoms may include the following:10

    • Agitation.
    • Anxiety.
    • Fever.
    • Insomnia.
    • Sweating.
    • Muscle aches and pains.
    • Abdominal cramping.
    • Diarrhea.
    • Nausea.
    • Vomiting.

These opioid painkiller withdrawal symptoms are uncomfortable but not life threatening.10

Painkillers Effects question 6


  1. United States Drug Enforcement Administration. (n.d.). Narcotics (Opioids).
  2. U.S. National Library of Medicine. (2019). MedlinePlus: Opioid Abuse and Addiction.
  3. Johns Hopkins Medicine. (n.d.). Opioid Addiction: What Are Opioids?
  4. National Institute on Drug Abuse. (2019). Opioid Overdose Crisis.
  5. U.S. National Library. (2018). MedlinePlus: Opioid Overdose.
  6. National Institute on Drug Abuse. (2007). The Neurobiology of Drug Addiction: 4: Opiates binding to opiate receptors in the nucleus accumbens: increased dopamine release.
  7. Benyamin, R., Trescot, A.M., Datta, S., Buenaventura, R., Adlaka, R., Sehgal, N., Glaser, S.E., Vallejo, R. (2008). Opioid complications and side effects. Pain Physician, 11(2 suppl), S105-120.
  8. National Institute on Drug Abuse. (2007). The Neurobiology of Drug Addiction: 6: Definition of tolerance.
  9. National Institute on Drug Abuse. (2018). Principles of Drug Addiction Treatment: A Research-Based Guide (Third Edition): Is there a difference between physical dependence and addiction.
  10. S. Food & Drug Administration. (2009). A Guide to Safe Use of Pain Medicine.
  11. National Institute on Aging. (2018). Pain: You Can Get Help.
  12. American College of Rheumatology. (2019). NSAIDs (nonsteroidal anti-inflammatory drugs).
  13. S. National Library of Medicine. (2017). MedlinePlus: Acetaminophen.
  14. Agrawal, S., Khazaeni, B. (2018). Acetaminophen Toxicity. Treasure Island (FL): StatPearls Publishing.

Last updated on November 4, 2019
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