Types of Analgesic Drugs with Mechanism and Examples
Analgesics are substances that reduce the effect of pain without causing any mental confusion, paralysis, or any other disturbance to the nervous system. That way, your nervous system does not become imbalanced and you actually eliminate the pain. In contrast to anesthesia, analgesics do not remove the sensation of pain as anesthetics do.
Various types of analgesics
The two main categories of analgesics are:
Non-narcotic (non-addictive) analgesics
The skeleton pain that can arise due to arthritis may be relieved with this type of medication. The most commonly prescribed drugs, in this case, are aspirin and paracetamol. To stop the production of prostaglandins by chemical reactions, aspirin inhibits the absorption of a substance known as prostaglandin. As a result, pain is felt in the tissues.
Helps in reducing fever, these drugs also help prevent the coagulation of platelets. In order to prevent heart attacks, aspirin works by preventing blood clotting.
Narcotic analgesics
A prescription analgesic drug relieves pain in a patient and produces sleep at the same time. It is possible for this drug to cause coma, convulsions, and finally death when taken in excessive amounts.
Since they are derived from the opium poppy, narcotic analgesics such as Morphine are also known as opiates. Painkillers commonly used in the treatment of postoperative pain, cardiac pain, and cancer pain are called narcotic analgesics.
Further Classification Of Analgesics Based On Their “Mechanism Of Action.”
Paracetamol (acetaminophen)
NSAIDs
COX-2 inhibitors
Opioids
Alcohol
Medical cannabis
Combinations
Alternative medicine
Adjuvants
Other drugs
Below are a few of them
Paracetamol (acetaminophen): Paracetamol is an analgesic that is also known as acetaminophen. The medication treats pain and fever.
Opioids: These substances have similar effects to opium. Various derivatives of the narcotic analgesic morphine are used.
Alcohol: Alcohol is an organic compound containing a hydroxyl functional group (-OH) such as ethanol. The impacts of using alcohol for pain are diverse, including biological, mental, and social effects.
Side Effects Of Various Analgesics
Euphoria, dysphoria, agitation, seizures, hallucinations.
Lowered blood pressure and heart rate.
Muscular rigidity and contractions.
Nausea and vomiting. Non-allergic itching.
Sexual dysfunction.
Urinary retention.
Sedation.
Dizziness.
Nausea.
Vomiting.
Constipation.
Physical dependence.
Tolerance.
Respiratory depression.
Points to Remember Before Consuming Analgesic Drugs
Non-narcotic drugs such as aspirin are important. However, they should not be taken in excessive amounts.
Even though aspirin is popular, it is supposed to be toxic to the liver. Salicylic acid is formed when the peptide gets hydrolyzed in the stomach, which sometimes causes stomach bleeding. Therefore, overdosing and using it on an empty stomach should be avoided.
It is more soluble and less harmful to take aspirin salts like calcium and sodium.
It is also important to consider the type of pain when selecting an analgesic. Typical analgesics are less effective in treating neuropathic pain, whereas tricyclic antidepressants and anticonvulsants, which are not typically considered analgesics, are usually beneficial.
The World Health Organization (WHO) specifies mild analgesics as the first step in its pain ladder. The choice of analgesic is based partially on severity and interactions with other medications.
Conclusion
It is important to understand the difference between narcotic and non-narcotic drugs, its various side effects, and also the important points to consider before consuming such medicines. For a simple and interesting way to learn about other topics of chemistry, please register at vedantu.com or download our app.
FAQs on Classification of Analgesic Drugs in Chemistry
1. What are analgesic drugs?
Analgesic drugs are medications that relieve pain without causing loss of consciousness. They act by reducing the production of pain-causing chemicals or by blocking pain signals in the nervous system.
- They are commonly used to treat headache, toothache, muscle pain, and inflammation.
- Examples include aspirin (C9H8O4), paracetamol (C8H9NO2), and morphine (C17H19NO3).
- In chemistry, analgesics are classified based on their chemical structure and mechanism of action.
2. How are analgesic drugs classified?
Analgesic drugs are mainly classified into non-narcotic (non-opioid) and narcotic (opioid) analgesics based on their chemical nature and action on the central nervous system.
- Non-narcotic analgesics: Relieve mild to moderate pain and reduce inflammation (e.g., aspirin, ibuprofen).
- Narcotic analgesics: Act on opioid receptors in the brain and are used for severe pain (e.g., morphine, codeine).
- Some classifications also include NSAIDs and COX-2 inhibitors under non-opioid analgesics.
3. What are non-narcotic analgesics?
Non-narcotic analgesics are pain-relieving drugs that do not cause addiction and are effective for mild to moderate pain. They mainly inhibit the enzyme cyclooxygenase (COX), reducing prostaglandin synthesis.
- Examples: aspirin (C9H8O4), paracetamol (C8H9NO2), ibuprofen (C13H18O2).
- They are often called NSAIDs (Non-Steroidal Anti-Inflammatory Drugs).
- They also reduce fever (antipyretic action).
4. What are narcotic analgesics?
Narcotic analgesics are opioid drugs that relieve severe pain by acting on opioid receptors in the central nervous system. They can produce sedation and may cause dependence.
- Examples: morphine (C17H19NO3), codeine (C18H21NO3).
- They are derived from opium or synthesized chemically.
- Used in post-surgical pain and cancer pain management.
5. What is the difference between narcotic and non-narcotic analgesics?
The main difference is that narcotic analgesics act on the central nervous system and may cause addiction, whereas non-narcotic analgesics act mainly at the site of pain and do not cause dependence.
- Narcotic: Strong pain relief, CNS action, risk of addiction (e.g., morphine).
- Non-narcotic: Mild to moderate pain relief, anti-inflammatory effect, no addiction (e.g., aspirin).
- Narcotics are used for severe pain; non-narcotics for common aches and inflammation.
6. What are NSAIDs in analgesic drug classification?
NSAIDs are Non-Steroidal Anti-Inflammatory Drugs that relieve pain, reduce inflammation, and lower fever by inhibiting COX enzymes. They block the synthesis of prostaglandins responsible for pain and swelling.
- Examples: ibuprofen (C13H18O2), diclofenac (C14H11Cl2NO2), aspirin.
- They are widely used for arthritis, muscle pain, and headache.
- They are non-opioid analgesics.
7. How does aspirin work as an analgesic?
Aspirin works as an analgesic by irreversibly inhibiting the cyclooxygenase (COX) enzyme, thereby reducing prostaglandin synthesis responsible for pain and inflammation. Its chemical name is acetylsalicylic acid (C9H8O4).
- It acetylates the COX enzyme, blocking its activity.
- Decreased prostaglandins lead to reduced pain and fever.
- It also has antipyretic and anti-inflammatory properties.
8. Is paracetamol a narcotic analgesic?
Paracetamol is not a narcotic analgesic; it is a non-narcotic (non-opioid) analgesic and antipyretic. Its chemical formula is C8H9NO2.
- It relieves mild to moderate pain.
- It reduces fever but has very weak anti-inflammatory action.
- It does not cause addiction or dependence like opioids.
9. What are examples of opioid analgesics?
Common examples of opioid analgesics are morphine, codeine, heroin, and fentanyl, which act on opioid receptors in the brain to relieve severe pain.
- Morphine: C17H19NO3
- Codeine: C18H21NO3
- They are used in post-operative and cancer pain management.
- They may cause tolerance, dependence, and respiratory depression.
10. Why are analgesics important in medicinal chemistry?
Analgesics are important in medicinal chemistry because they help in designing and synthesizing drugs that selectively relieve pain with minimal side effects. Their study involves structure–activity relationship (SAR) analysis and mechanism-based drug design.
- Understanding opioid receptor binding improves safer opioid development.
- Modification of NSAID structure reduces gastric side effects.
- They are widely used in clinical therapy and pharmaceutical research.
