15.3: Analgesics
- Page ID
- 341989
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)
\( \newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\)
( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\)
\( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)
\( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\)
\( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)
\( \newcommand{\Span}{\mathrm{span}}\)
\( \newcommand{\id}{\mathrm{id}}\)
\( \newcommand{\Span}{\mathrm{span}}\)
\( \newcommand{\kernel}{\mathrm{null}\,}\)
\( \newcommand{\range}{\mathrm{range}\,}\)
\( \newcommand{\RealPart}{\mathrm{Re}}\)
\( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)
\( \newcommand{\Argument}{\mathrm{Arg}}\)
\( \newcommand{\norm}[1]{\| #1 \|}\)
\( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)
\( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\AA}{\unicode[.8,0]{x212B}}\)
\( \newcommand{\vectorA}[1]{\vec{#1}} % arrow\)
\( \newcommand{\vectorAt}[1]{\vec{\text{#1}}} % arrow\)
\( \newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\( \newcommand{\vectorC}[1]{\textbf{#1}} \)
\( \newcommand{\vectorD}[1]{\overrightarrow{#1}} \)
\( \newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}} \)
\( \newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}} \)
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)
\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)- Define the term "analgesic."
- Compare and contrast OTC analgesics with Narcotic analgesics.
- Relate the four common OTC analgesic's generic names to chemical and Brand names.
- Know side effects of taking each of the four OTC analgesics.
- Explain what buffering does to a medication.
- Detect analgesics in a combination medication.
- Determine what the different drugs in a combination medicine do (when provided a label)
- Compare and contrast opiates with opioids.
- Determine which mg amount corresponds to the opioid when provided a label of a narcotic analgesic.
- Know the medical purposes and side effects of taking a narcotic.
- Provide the name for the strongest narcotic on this page.
- Understand how Oxycontin differs from oxycodone.
- Provide a list of medications/substances that should not be combined with narcotics.
- Name one antidote for opioid/opiate overdose.
- Describe the history of the early opiates.
- Explain what "doctor shopping" is.
Analgesics are medications that relieve pain. Many of these medications can be purchased without a prescription and are labeled as being over the counter (OTC). All of these OTC formulations have generic counterparts that are chemically equivalent to the brand name. When purchasing these substances, be sure to note the price difference between generic and name-brand analgesics. Also, you should be aware that countries outside the United States use different names for their analgesics and dosages per unit.
Selecting an OTC Analgesic
For general and occasional pain, consumers have the option of taking one of four OTC pain killers. All of these medications act as antipyretics. Of the four drugs, only one of these analgesics cannot alleviate pain due to inflammation.
Acetaminophen (Tylenol®, Paracetamol®)
American formulations of this OTC pain killer are available in regular strength (325 mg of acetaminophen per tablet) or extra strength (500 mg of acetaminophen per tablet). Dosages should be extended to 4-6 hour increments when treating fever. Acetaminophen reduces general pain but is not a nonsteroidal anti-inflammatory drug (NSAID). It does not demonstrate anticoagulant effects and is the safest to use on pregnant women and pediatric patients. Of the four OTC analgesics, this molecule does not contain an organic acid functional group (COOH). Being a somewhat pH-neutral molecule, acetaminophen is milder on the stomach than the other analgesics listed below.
Organic and biochemists are both employed in the making of pharmaceuticals. The reaction pathways drawn to describe the steps of synthesis are called mechanisms. Click on the short video below to visualize the reaction mechanism utilized to produce acetaminophen.
Acetylsalicylic Acid (Bayer Aspirin®, Goody's®, Ecotrin®)
In 1853, French chemist, Charles Gerhardt, synthesized the organic molecule known today as acetylsalicylic acid. Medical applications of this molecule did not occur until the later part of the 1890s. German chemist, Felix Hoffman, produced the first pure sample of acetylsalicylic acid. In hopes to alleviate the intense pain associated with rheumatoid arthritis, the Bayer Chemical Company's trademark Aspirin® was marketed to the European continent. Immediately after World War I, Bayer's Aspirin and Heroin trademark products were given to allied nations as part of the Treaty of Versailles agreement.
Aspirin, like Tylenol ®, can reduce fevers and general pain. This particular pharmaceutical is an anticoagulant and NSAID. The acetylsalicylic acid molecule does contain an organic acid functional group (COOH). As a result of this molecular structure, Aspirin products can be harsh on the stomach and gastrointestinal tract. At high doses Concentrations of the active ingredient acetylsalicylic acid, can be 81 mg (heart therapy), 325 mg (regular strength), and 500 mg (extra strength).
Due to its anticoagulant properties, aspirin products should be avoided by people who have bleeding diseases and who are undergoing surgery. For this reason, pregnant women should avoid aspirin therapy unless a physician notes otherwise. Pediatric patients could develop Reye's Syndrome if they use aspirin-based medications to reduce fevers. Individuals who take high doses of aspirin can experience tinnitus (ringing in the ears). This analgesic can also trigger respiratory events in asthmatic patients.
Buffered Aspirin
This type of aspirin contains an antacid ingredient, various carbonates CO32-, and/or weak hydroxides OH-, that will minimize the acidic effects of this analgesic. The normal pH of stomach acid is around 1. Regular (or non-buffered) aspirin-based products can reduce this value even more. A buffered analgesic will keep the stomach pH value stable and will reduce the likelihood of developing stomach ulcers and reflux. Generics and the trade brand Bufferin® are available as OTC options.
_chart.svg.png?revision=1&size=bestfit&width=490&height=414)
Ibuprofen (Advil® and Motrin®)
In the 1950s, British chemist, Stewart Adams, focused his research on developing a new drug that would minimize the effects of rheumatoid arthritis. For years, aspirin products were used, but several adverse reactions had been reported. Favorable clinical trials led to a patient that was granted to Adams's employer, Boots UK. By 1969, ibuprofen was available as a prescription medication in the UK. Prescription availability in the United States occurred in 1974. Both the UK and the United States converted the statues of ibuprofen from prescription to over-the-counter in the early to mid-1980s.
Ibuprofen does contain the acidic COOH group. For this reason, it is best for patients with stomach issues to avoid or minimize the use of this analgesic. Being an antipyretic and NSAID, this medication is safe for use for those who do not have bleeding disorders (anticoagulant). OTC regular-strength tablets or capsules contain 200 mg of the active ingredient. Like Tylenol, it is recommended that patients should wait between 4-6 hours between dosages. Some asthmatics have experienced mild to severe reactions while taking this drug. Of the four OTC analgesics shown on this page, acetaminophen and ibuprofen are safe to use on pediatric patients provided they are not asthmatic or have gastrointestinal problems.
Ibuprofen is extremely effective in treating dysmenorrhea. With the addition of caffeine, the painkilling effect can be intensified with analgesics like acetaminophen, aspirin, and ibuprofen.
Naproxen (Aleve®)
This analgesic possesses the longest chemical half-live (12 hours) than the previously mentioned medications. For this reason, it is recommended to extend dosage to 8-12 hours (other analgesics are dosed between 4-6 hours).
The naproxen sodium formulation of this NSAID is more rapidly absorbed than the naproxen version. Both versions are NSAIDS and act as antipyretics. Once again, the acidic COOH group is present and will cause adverse reactions in individuals who suffer from gastrointestinal issues. Sold in 220 mg tablets, naproxen has anticoagulant properties which make it a risky option for many types of patients (pre-surgical and pregnant women). Lastly, naproxen products can trigger asthma symptoms.
If a patient has kidney or liver disease, it is best to avoid all analgesics. Liver damage is more common when combining alcohol with analgesics or if taking excessive amounts of these medications. If taken on a daily basis, tolerance to an analgesic can occur.
Combination Products
When taking combination products for allergies, colds, flu, or other illnesses, it is important to note all the active ingredients listed in a product. For example, many cold and flu formulations contain an analgesic with antihistamines and/or decongestants. By analyzing the label, a consumer is less likely to double up on one of the listed ingredients. For example, the OTC flu medication displayed below contains an analgesic, cough suppressant, and a nasal decongestant. When taking Theraflu, there is no need to take an additional analgesic.
Pediatric formulations of analgesics or combination products that include analgesics will have different concentrations of active ingredients than medicine that has been designed for adults. By following the dosing directions on the packaging, adults can ensure that they are not under or over-dosing a child.
Look up the following combination products and determine the analgesics that are present. Also, indicate applications for each pharmaceutical.
a) Pamprin®
b) Excedrin®
c) Nyquil® and Dayquil®
d) Mucinex Sinus-Max®
Narcotic Analgesics
For intense pain and/or chronic pain, narcotics could be prescribed by a health care professional. These substances are very addictive and classified DEA schedule 2. The term "Opiate" implies that a narcotic-based pain killer could be derived from the opium poppy. In nature, the seed pod of the opium poppy plant excretes codeine and morphine.
Figure \(\PageIndex{9}\): This photo shows a seed head of Opium Poppy Papaver somniferum with white latex.
Opium poppies are commonly grown in many parts of the Middle East, Asia, and South America. Here, the sap is extracted and collected. Upon exposure to air, the sap turns brown and is then formed into a ball-like structure. Crude opium can enter the pharmaceutical industry legally if imported and processed correctly. Many countries do not allow opium-based poppies to be grown and extraction of the natural opiates to occur.
Even though opiates are natural products of a plant, they can also be synthesized in an organic chemistry laboratory. If morphine and are codeine are produced in a chemical laboratory, we now refer to these substances as being opioids. Both of these compounds can exist naturally and can be made by a chemist. Narcotics, like oxycodone, hydrocodone, and heroin are classified as being opioids as well. These three compounds along with others cannot be extracted from a plant and are made in a laboratory.
Medical applications of opiates and opioids
Hospitals can dispense morphine or fentanyl for patients who are experiencing extreme pain. This could include pain resulting from surgery or trauma. Fentanyl is also applied in the palliative care field of medicine. Lesser potent opioids, like codeine, are used to suppress the cough reflex for flu patients. Over-the-counter cough syrups do not include codeine and therefore are not classified as controlled substances.
Figure \(\PageIndex{10}\): Promethazine-codeine cough syrup. (Copyright, https://commons.wikimedia.org/wiki/User:Stickpen)
When leaving the hospital, a patient might be prescribed narcotics that have relatively low doses of oxycodone or hydrocodone. Typically, these opioids are combined with an over-the-counter analgesic and have brand names like Lortab® (hydrocodone/acetaminophen), Percocet® (oxycodone/acetaminophen), or Percodan® (oxycodone/aspirin).
Figure \(\PageIndex{11}\): Vicodin prescription label. (Copyright, https://search.creativecommons.org/p...9-9d0cf0a2a430).
Often, narcotics are combined with over-the-counter analgesics. The label shown above is a combination medicine that can be prescribed for at-home pain management. Vicodin is a combination of hydrocodone and acetaminophen. The dosage on this label is 5-500mg. The first of these two values (5mg) will always coincide with the narcotic concentration. The second of these two numbers represents the acetaminophen concentration. If a medication already contains an OTC analgesic, then do not double up by taking an additional OTC drug or another narcotic-based pill.
If a patient is dispensed with pure oxycodone, then this drug is equivalent to Oxycontin®. This medication does not contain an over the counter analgesic. It is not available in generic form and uses an extended timed release mechanism. Legal concentrations for this particular opioid range from 5 to 80 mg. Within the past couple of years, the drug's manufacture (Purdue Pharma) has been investigated and sued regarding the marketing and use of this medication. Watch the clip below to see one perspective of how this medication has affected the opioid crisis.
Narcotics are extremely addictive and cause many different health issues. These medications should only be utilized to treat severe pain. Also, patients who are prescribed drugs that contain hydrocodone or oxycodone should attempt to transition from these controlled substances to an OTC analgesic as soon as possible. Common side effects of hydrocodone and oxycodone include euphoria, sedation, dizziness, nausea, vomiting, respiratory depression, severe constipation, and addiction.
Figure \(\PageIndex{12}\): National Drug-Involved Overdose Deaths by Specific Category—Number Among All Ages, 1999-2019. Overall, drug overdose deaths rose from 2018 to 2019 with 70,630 drug overdose deaths reported in 2019. Deaths involving other synthetic opioids other than methadone (primarily fentanyl) continued to rise with more than 36,359 overdose deaths reported in 2019. Those involving psychostimulants with abuse potential (primarily methamphetamine) also continued to increase (Source: CDC WONDER)." (Copyright, National Institute on Drug Abuse).
It is important to never mix narcotics with any other controlled substance or alcohol. Narcotics depress the respiratory system. Alcohol and antianxiety drugs, like Valium® and Xanax®, can affect breathing rate and the lung's ability to process oxygen. As a result, narcotic users could lose consciousness and die.
Heroin (diacetylmorphine)
.png?revision=1)
Figure \(\PageIndex{13}\): Structure of heroin. (Copyright, https://commons.wikimedia.org/wiki/User:NEUROtiker)
Unfortunately, prescription-based narcotics are known to be heavily abused. One may choose to "doctor shop" in order to obtain additional prescriptions for legal, narcotic analgesics. In order to acquire multiple prescriptions, a person might choose to solicit a physician who resides in a different town and/or state. If unsuccessful, a patient could focus their efforts in acquiring a DEA schedule I substance, Heroin.
Figure \(\PageIndex{14}\): Bayer heroin bottle, originally containing 5 grams of Heroin substance. The label on the back-references the 1924 US ban, and has a batch number stamp starting with 27, so it probably dates from the 1920s. (Copyright, https://en.Wikipedia.org/wiki/User:Mpv_51)
First synthesized around the mid-1870s as an alternative to morphine. At the time, Civil War veterans were heavily addicted to morphine . Before and during the Civil War, this narcotic was used to treat pain and dysentery. Regrettably, research reported that Heroin was more addictive and more powerful (3 to 5 times) than its precursor
Heroin is classified as being an opioid. This narcotic can be produced semisynthetically by extracting the morphine from an opium poppy. Then, an acid is added to produce the chemical structure that is shown above. Heroin can be obtained from pure synthetic means as well.
Naloxone (Narcan®)
Signs of a narcotic overdose include constricted pupils, loss of consciousness, chocking/gurgling sounds, clammy/discolored skin, and limp body. Emergency services (EMS) should be called immediately and attempt should be made to keep the person awake (while laying them on their side). Once EMS arrives they will administer naloxone via a nose spray or injection. This medication occupies the opiate/opioid receptor sites within the brain. Molecules like naloxone remove the narcotic effect and in most cases save lives.