Skip to content

Difference between Antibiotic and Analgesic


Doctors often prescribe analgesics and antibiotics when probiotics fail to help your body. These drugs are used to treat different infections and diseases. Analgesics act on pain receptors to reduce pain in different body parts and are available on-the-counter. However, antibiotics are not OTC medicines and must only be taken when prescribed by a doctor.

Both medications are used for different ailments in the body. However, you should still take them with care to avoid unwanted effects. Let’s tell you about the differences between antibiotics and analgesics in detail.

Comparison Table

FunctionTreat infectionsManage pain
Date of
TypesPenicillin, cephalosporins,
macrolides, sulfonamides
Anti-migraines, NSAIDs,
COX-2 inhibitors, salicylates
IntakeProphylactic/after infectionOn sensation of pain
of Dose
FixedOnly per symptoms
Toxicitynausea, vomiting,
dizziness, anxiety
Over 2 mg a day
ExamplesAmoxicillin, cefaclor,
ciprofloxacin, gentamicin
Naproxen, NSAIDS,
ibuprofen, aspirin

What are Antibiotics?

The word antibiotic is a combination of “anti” and “biotic.” Anti means against, whereas biotic relates to life. Thus, antibiotic literally translates to ‘against life.’

Antibiotics are a group of drugs that help treat infections by killing or stopping the activity of microorganisms, especially bacteria.

It means antibiotics usually treat bacterial infections, but not the viral infections. However, drugs like antiviral are used for viral infections.

Antibiotics treat a wide range of diseases caused by bacteria. They are obtained from natural sources, prepared by altering natural antibiotics (semi-synthetic) or produced synthetically.

They may be administered by oral, IV, or topical routes. Commonly available forms of antibiotics include pills, IV infusion, and ointments.


History of Antibiotics

Alexander Fleming discovered the first antibiotic known to humankind, Penicillin, in 1928. However, prontosil (sulfonamide) was the first commercial antibiotic developed by German biochemist Gerhard Domagk.

In 1942, Penicillin was introduced to the public and used to treat streptococcal meningitis. Florey and Chain enabled the production of antibiotics safely on a large scale. Most other antibiotics were discovered and created till 1962, also known as the Golden Era of Antibiotics. Fleming, Florey, and Chain shared the 1945 Nobel Prize in Physiology or Medicine for this achievement.

Mechanism of Action

Different types of antibiotics follow a specific mechanism of action. Nevertheless, they act to inhibit the activity of the bacteria by killing the bacteria or altering its structure. Antibiotics are either bactericidal or bacteriostatic, depending on their nature.

All antibiotics act on one of the following targets to produce their action on microbes.

Types of Antibiotics

Antibiotics are categorized per different parameters. The most extensively applied classification divides antibiotics into seven classes.

  • Penicillins
  • Cephalosporins
  • Macrolides
  • Fluoroquinolones (broad-spectrum antibiotics)
  • Sulfonamides
  • Tetracycline
  • Other types of antibiotics


The dosage and frequency of antibiotics depend on the antibiotic class and duration of action. Typically the dose is 250 mg to 500 mg every 12 hours for a specified number of days. Make sure to take antibiotics per doctor’s prescription to avoid antibiotic resistance.

Antibiotic Toxicity

Toxicity is typically not associated with antibiotics as people develop resistance to them. However, fluoroquinolones have been seen to produce toxicity in some individuals. Researchers suggest that there is wide scope for antibiotic toxicity treatment that must not be overlooked. Experts have found out that they damage mitochondria in human cells. Moreover, antibiotics can also cause constipation.

Examples of Antibiotics

Some of the most commonly used antibiotics for bacterial infections include amoxicillin, doxycycline, ciprofloxacin, azithromycin, and metronidazole.

What are Analgesics?

Analgesics are generally known as painkillers and available as OTC medication though a few require prescriptions. They treat and relieve pain associated with general body pains, osteoarthritis and rheumatoid arthritis, post-surgery pain, etc. Now, various analgesics are available for relieving joint pain, migraine, and menstrual pain as well.

Analgesics are often confused with anesthetic medicines. Analgesics do not act on your nerves to turn off the sensation, instead they act on receptors to reduce pain. Analgesics are available in various dosage forms, including oral medicines, topical creams, and suppositories.


History of Analgesics 

Initially, people used different botanical elements, like herbs containing analgesic components, for pain management. By 1950, various morphine-like drugs had been developed as pain-relief medication. But, the breakthrough occurred following the discovery of potent naturally occurring analgesic pentapeptides. This discovery is attributed to neuroscientists John W. Hughes and Hans W. Kosterlitz at the University of Aberdeen in Scotland.

Mechanism of Action

Analgesics stop the sensation of pain by inhibiting the transmission of impulses and changing the feeling of pain through the use of opioids. Furthermore, NSAIDs perform their analgesic action through peripheral inhibition of prostaglandin synthesis and other peripheral and central mechanisms. COX-1 and COX-2 inhibition to stop prostaglandin synthesis is the most likely mechanism of action to produce a pain-relief effect.

Types of Analgesics

Analgesics are categorized based on their mechanism of action and how they impact the pain receptors. The most common types of available antibiotics include:


The dose of analgesics also varies according to the type of analgesic you are taking. The typical dose of paracetamol is 325 to 500 mg orally every 4 hours or 500 to 1000 mg every 6 to 8 hours; the dose must not increase over 2 mg per day.

Analgesic Toxicity

Analgesic toxicity may result from high-dose single-drug or multiple-drug intake. Fentanyl, acetaminophen, and oxycodone are high-risk poisoning analgesics. Unmanaged high doses of analgesics may lead to analgesic nephropathy and need an antidote. The doctor may initially administer charcoal or naloxone in case of opioid poisoning.

Examples of Analgesics

Common analgesic examples include paracetamol, ibuprofen, NSAIDs, opioids, and morphine. They are used for different kinds of pain depending on the need.

Differences between Antibiotic and Analgesic



Antibiotics treat infections caused by various bacteria. Antifungal antibiotics help with fungal infections.


Analgesics are painkillers used to help with different forms of pain caused by local conditions or systemic diseases.



Alexander Fleming first discovered antibiotic Penicillin in 1928. It was first introduced commercially in 1942.


The development of morphine-like drugs in 1950 was the major breakthrough for analgesics. John W. Hughes and Hans W. Kosterlitz later discovered analgesic pentapeptides.



Antibiotics are classified as penicillins, cephalosporins, macrolides, fluoroquinolones (broad-spectrum antibiotics), sulfonamides, and tetracyclines.


Various analgesics are used in medical practice, including analgesic combinations, antimigraine agents, NSAIDs (Nonsteroidal anti-inflammatory drugs), COX-2 inhibitors, CGRP inhibitors, narcotic analgesic combinations, narcotic analgesics, and salicylates.



Antibiotics are typically taken after an infection. Yet, sometimes doctors may give patients antibiotics before surgery because of the high risk of infection.


Analgesics, on the contrary, are taken on the onset of pain in one or more parts of the body.

Dosage Duration


Antibiotics must be taken for a specific period to stop the bacteria’s activity or kill them. Not completing the course may lead to antibiotic resistance.


Analgesics are taken only when pain arises as they are used to treat symptomatic pain. They should not be used long-term unless advised by a doctor.



Examples of antibiotics include amoxicillin, tetracycline, ciprofloxacin, azithromycin, etc.


Examples of analgesics are paracetamol, NSAIDS, ibuprofen, etc.

The Bottom Line

Antibiotics and analgesics are widely utilized in the treatment of the signs and symptoms of different diseases. Antibiotics are taken pre or post-infection to stop bacterial activity, whereas analgesics are painkillers that help relieve pain. Despite their different mechanisms of action, they contribute to better healthcare for the patients against nutritional diseases, antigens and pathogens. The intake protocol of both kinds of medicines is a major difference between analgesics and antibiotics. Analgesics are available as OTC medicines, while antibiotics should only be taken on prescription from a doctor.


Can I take antibiotics and analgesics together?

Antibiotics and analgesics are widely taken together for different underlying conditions, and they are the same to take together. However, it is always better to consult your GP before taking medicines at the same time.

What is the difference between pain reliever and analgesic?

Analgesics and pain relievers are two names for the same type of medication. They are used to help patients manage pain. However, they differ from anesthesia used during surgery to reduce or avoid pain.

Is Tylenol considered an analgesic?

Tylenol is one of the most common analgesics. It is an acetaminophen widely used for pain relief and to alleviate fever.

Why do doctors recommend Tylenol over ibuprofen?

Ibuprofen is an NSAID (non-steroidal anti-inflammatory drug). Thus, it is usually used when the pain is due to inflammation. If the pain does not arise from inflammation, analgesics are preferred.

Is Penicillin an antibiotic or analgesic?

Penicillin is an antibiotic. In fact, it was the first ever antibiotic naturally discovered to treat bacterial infections. It treats a wide range of bacteria to treat infections orally or through IV.

Why do US doctors not prescribe antibiotics?

Antibiotics have a common use in some countries, but developed countries do not encourage the use of antibiotics. Too much antibiotics can lead to antibiotic resistance. Many infections do not require antibiotics and must not be treated with them.

Leave a Reply

Your email address will not be published. Required fields are marked *