Antibiotic; Types, Indications/Uses , Side Effects, Interactions

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Article Summary

Antibiotic also called an antibacterial is a type of antimicrobial drug used in the treatment and prevention of bacterial infections.They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity.Antibiotics are not effective against viruses such as the common cold or influenza; drugs which inhibit viruses are termed antiviral drugs or antivirals rather than antibiotics. Sometimes the term antibiotic (which means "opposing life") is used to refer to any substance used against microbes, synonymous with antimicrobial. Some sources distinguish between antibacterial and antibiotic; antibacterials are...

Key Takeaways

  • This article explains New Antibiotics in simple medical language.
  • This article explains Penicillins in simple medical language.
  • This article explains Cephalosporins in simple medical language.
  • This article explains Monobactams in simple medical language.
Educational health guideWritten for patient understanding and clinical awareness.
Reviewed content workflowUse writer and reviewer profiles for stronger trust.
Emergency safety firstUrgent warning signs are highlighted below.

Seek urgent medical care if you notice

These warning signs are general safety guidance. Local emergency numbers and clinical judgment should always come first.

  • Severe symptoms, breathing difficulty, fainting, confusion, or rapidly worsening illness.
  • New weakness, severe pain, high fever, or symptoms after a serious injury.
  • Any symptom that feels urgent, unusual, or unsafe for the patient.
1

Emergency now

Use emergency care for severe, sudden, rapidly worsening, or life-threatening symptoms.

2

See a doctor

Book a professional medical evaluation if symptoms persist, worsen, recur often, affect daily activities, or occur in a high-risk patient.

3

Learn safely

Use this article to understand possible causes, tests, treatment options, prevention, and questions to ask your clinician.

bacterial infections. সহজ বাংলা: ব্যাকটেরিয়ার সংক্রমণের ওষুধ।" data-rx-term="antibiotic" data-rx-definition="An antibiotic is a medicine used to treat bacterial infections. সহজ বাংলা: ব্যাকটেরিয়ার সংক্রমণের ওষুধ।">Antibiotic also called an antibacterial is a type of antimicrobial drug used in the treatment and prevention of bacterial infections.They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity.Antibiotics are not effective against viruses such as the common cold or influenza; drugs which inhibit viruses are termed antiviral drugs or antivirals rather than antibiotics.

Sometimes the term bacterial infections. সহজ বাংলা: ব্যাকটেরিয়ার সংক্রমণের ওষুধ।" data-rx-term="antibiotic" data-rx-definition="An antibiotic is a medicine used to treat bacterial infections. সহজ বাংলা: ব্যাকটেরিয়ার সংক্রমণের ওষুধ।">antibiotic (which means “opposing life”) is used to refer to any substance used against microbes, synonymous with antimicrobial. Some sources distinguish between antibacterial and bacterial infections. সহজ বাংলা: ব্যাকটেরিয়ার সংক্রমণের ওষুধ।" data-rx-term="antibiotic" data-rx-definition="An antibiotic is a medicine used to treat bacterial infections. সহজ বাংলা: ব্যাকটেরিয়ার সংক্রমণের ওষুধ।">antibiotic; antibacterials are used in soaps and disinfectants, while antibiotics are used as medicine

New Antibiotics

ClassGeneric/Brand
LipopeptidesDaptomycin (Cubicin®), 2003
FluoroquinoloneDelafloxacin (Baxdela®), 2017
LipoglycopeptidesTelavancin (Vibativ®), 2009
Cephalosporin
(5th generation)
Ceftaroline (Teflaro®), 2010
MacrocyclicsFidaxomicin (Dificid®), 2011

ß-Lactam Antibiotics

Beta-lactam class of antibiotics includes penicillins, cephalosporins, monobactams, and carbapenems, all of which contain a β-lactam ring.

Penicillins

Antibiotics of the penicillin class are bactericidal and work by inhibiting the synthesis of bacterial cell walls. Penicillins are among the safest antibiotics.

Major health concerns: hypersensitivity reactions.

GenericBrand Name
AmoxicillinAmoxil, Polymox, Trimox, Wymox
AmpicillinOmnipen, Polycillin, Polycillin-N, Principen, Totacillin
BacampicillinSpectrobid
CarbenicillinGeocillin, Geopen
CloxacillinCloxapen
DicloxacillinDynapen, Dycill, Pathocil
FlucloxacillinFlopen, Floxapen, Staphcillin
MezlocillinMezlin
NafcillinNafcil, Nallpen, Unipen
OxacillinBactocill, Prostaphlin
Penicillin GBicillin L-A,
Crysticillin 300 A.S., Pentids, Permapen, Pfizerpen, Pfizerpen-AS, Wycillin
Penicillin VBeepen-VK, Betapen-VK, Ledercillin VK, V-Cillin K
PiperacillinPipracil
Pivampicillin
Pivmecillinam
TicarcillinTicar

Cephalosporins

Cephalosporins are mainly bactericidal and act by inhibiting the synthesis of the peptidoglycan layer of bacterial cell walls. Besides true cephalosporins (which are derived from cephalosporin C) this class includes oxacephems and carbacephems.

Major health concerns: platelet function abnormalities (rare).

GenericBrand Name
First Generation
Cefacetrile (cephacetrile)Celospor, Celtol, Cristacef
Cefadroxil (cefadroxyl)Duricef, Ultracef
Cefalexin (cephalexin)Keflex, Keftab
Cefaloglycin (cephaloglycin)Kefglycin
Cefalonium (cephalonium)
Cefaloridine (cephaloradine)
Cefalotin (cephalothin)Keflin
Cefapirin (cephapirin)Cefadyl
Cefatrizine
Cefazaflur
Cefazedone
Cefazolin (cephazolin)Ancef, Kefzol
Cefradine (cephradine)Velosef
Cefroxadine
Ceftezole
Second Generation
CefaclorCeclor, Ceclor CD, Distaclor, Keflor, Ranicor
CefamandoleMandol
Cefmetazole
CefonicidMonocid
CefotetanCefotan
CefoxitinMefoxin
Cefprozil (cefproxil)Cefzil
CefuroximeCeftin, Kefurox, Zinacef, Zinnat
Cefuzonam
Third Generation
Cefcapene
Cefdaloxime
CefdinirOmnicef, Cefdiel
CefditorenSpectracef
Cefetamet
CefiximeSuprax
CefmenoximeCefmax
Cefodizime
CefotaximeClaforan
Cefpimizole
CefpodoximeVantin
Cefteram
CeftibutenCedax
CeftiofurExcede
Ceftiolene
CeftizoximeCefizox
CeftriaxoneRocephin
CefoperazoneCefobid
CeftazidimeCeptaz, Fortum, Fortaz, Tazicef, Tazidime
Fourth Generation
Cefclidine
CefepimeMaxipime
Cefluprenam
Cefoselis
Cefozopran
CefpiromeCefrom
Cefquinome
Fifth Generation
CeftobiproleZeftera
CeftarolineTeflaro
Not Classified
Cefaclomezine
Cefaloram
Cefaparole
Cefcanel
Cefedrolor
Cefempidone
Cefetrizole
Cefivitril
Cefmatilen
Cefmepidium
Cefovecin
Cefoxazole
Cefrotil
Cefsumide
Cefuracetime
Ceftioxide
Combinations
Ceftazidime/AvibactamAvycaz
Ceftolozane/TazobactamZerbaxa

Monobactams

GenericBrand Name
AztreonamAzactam, Cayston

Carbapenems

Carbapenems have incredibly broad spectrum of antimicrobial activity. Today these agents are among the most powerful antibiotics.

GenericBrand Name
Imipenem,
Imipenem/cilastatin
Primaxin
DoripenemDoribax
ErtapenemInvanz
MeropenemMerrem
Meropenem/vaborbactamVabomere

Macrolide Antibiotics

Macrolides are bacteriostatic drugs that inhibit protein synthesis by targeting the 50S subunit.

Major health concerns: erythromycin estolate is hepatotoxic.

GenericBrand Name
AzithromycinZithromax
Erythromycin
ClarithromycinBiaxin
DirithromycinDynabac
RoxithromycinRulid, Surlid
Ketolides
TelithromycinKetek

Lincosamides

GenericBrand Name
ClindamycinCleocin
LincomycinLincocin

Streptogramins

GenericBrand Name
PristinamycinPyostacine
Quinupristin/dalfopristinSynercid

Aminoglycoside Antibiotics

Aminoglycosides are rapidly bactericidal antibiotics which inhibit protein synthesis. These agents mainly interfere with proofreading process. Aminoglycosides are the only bactericidal class among protein synthesis inhibitors.

Major health concerns: ototoxicity, nephrotoxicity.

GenericBrand Name
AmikacinAmikin
GentamicinGaramycin, G-Mycin, Jenamicin
KanamycinKantrex
NeomycinMycifradin, Myciguent
NetilmicinNetromycin
Paromomycin
Streptomycin
TobramycinNebcin

Quinolone Antibiotics

Fluoroquinolones directly inhibit the bacterial nucleic acid synthesis.

Major health concerns: QTc prolongation and/or torsade de pointes, tendonitis, tendon rupture, joint arthropathies.

GenericBrand Name
First Generation
FlumequineFlubactin
Nalidixic acidNegGam, Wintomylon
Oxolinic acidUroxin
Piromidic acidPanacid
Pipemidic acidDolcol
RosoxacinEradacil
Second Generation
CiprofloxacinCipro, Cipro XR, Ciprobay, Ciproxin
EnoxacinEnroxil, Penetrex
LomefloxacinMaxaquin
NadifloxacinAcuatim, Nadoxin, Nadixa
NorfloxacinLexinor, Noroxin, Quinabic, Janacin
OfloxacinFloxin, Oxaldin, Tarivid
PefloxacinPeflacine
RufloxacinUroflox
Third Generation
BalofloxacinBaloxin
GatifloxacinTequin, Zymar
GrepafloxacinRaxar
LevofloxacinCravit, Levaquin
MoxifloxacinAvelox, Vigamox
PazufloxacinPasil, Pazucross
SparfloxacinZagam
TemafloxacinOmniflox
TosufloxacinOzex, Tosacin
Fourth Generation
BesifloxacinBesivance
DelafloxacinBaxdela®
Clinafloxacin
GemifloxacinFactive
PrulifloxacinQuisnon
SitafloxacinGracevit
TrovafloxacinTrovan

Sulfonamides

Sulfonamides act by inhibiting the pathway that bacteria use to synthesize folic acid. Sulfonamides with trimethoprim produce synergistic antibacterial activity.

Major health concerns: hypersensitivity reactions, renal damage, crystal nephropathy.

GenericBrand Name
SulfamethizoleThiosulfil Forte
SulfamethoxazoleGantanol, Urobak
SulfisoxazoleGantrisin
Trimethoprim-SulfamethoxazoleBactrim, Bactrim DS, Cotrim, Cotrim DS, Septra, Septra DS, Sulfatrim, Sulfatrim-DS

Tetracycline Antibiotics

Tetracyclines are protein synthesis inhibitors primary targeting the 30S ribosome. They are essentially bacteriostatic.

Major health concerns: photosensitivity, deposition in developing bones and teeth.

GenericBrand Name
DemeclocyclineDeclomycin
DoxycyclineDoryx, Vibramycin
MinocyclineDynacin, Minocin, Monodox
OxytetracyclineTerramycin
TetracyclineAchromycin
Glycylcyclines
TigecyclineTygacil

Other Antibiotics

GenericBrand Name
ChloramphenicolChloromycetin
MetronidazoleFlagyl, Helidac, Metizol, Metric 21, Neo-Metric, Noritate, Novonidazol
TinidazoleTindamax
NitrofurantoinFuradantin, Macrobid, Macrodantin
Glycopeptides
VancomycinVancocin
TeicoplaninTargocid
Lipoglycopeptides
TelavancinVibativ
Oxazolidinones
LinezolidZyvox
CycloserineSeromycin
Rifamycins
RifampinRifadin
RifabutinMycobutin
RifapentinePriftin
Rifalazil
Polypeptides
BacitracinBaciguent
Polymyxin B
Tuberactinomycins
Viomycin
Capreomycin

Mechanism of Action of Antibiotics

Antibiotics like the penicillins, is a beta-lactam bacterial infections. সহজ বাংলা: ব্যাকটেরিয়ার সংক্রমণের ওষুধ।" data-rx-term="antibiotic" data-rx-definition="An antibiotic is a medicine used to treat bacterial infections. সহজ বাংলা: ব্যাকটেরিয়ার সংক্রমণের ওষুধ।">antibiotic. By binding to specific penicillin-binding proteins (PBPs) located inside the bacterial cell wall, it inhibits the third and last stage of bacterial cell wall synthesis. Cell lysis is then mediated by bacterial cell wall autolytic enzymes such as autolysins; it is possible that antibiotic interferes with an autolysin inhibitor.

bacterial infections. সহজ বাংলা: ব্যাকটেরিয়ার সংক্রমণের ওষুধ।" data-rx-term="antibiotic" data-rx-definition="An antibiotic is a medicine used to treat bacterial infections. সহজ বাংলা: ব্যাকটেরিয়ার সংক্রমণের ওষুধ।">Antibiotic a beta-lactam antibiotic similar to penicillins, inhibits the third and final stage of bacterial cell wall synthesis by preferentially binding to specific penicillin-binding proteins (PBPs) that are located inside the bacterial cell wall. Penicillin-binding proteins are responsible for several steps in the synthesis of the cell wall and are found in quantities of several hundred to several thousand molecules per bacterial cell. Penicillin-binding proteins vary among different bacterial species. Thus, the intrinsic activity of  antibiotic as well as the other cephalosporins and penicillins against a particular organism depends on their ability to gain access to and bind with the necessary PBP. Like all beta-lactam antibiotics, it ability to interfere with PBP-mediated cell wall synthesis ultimately leads to cell lysis. Lysis is mediated by bacterial cell wall autolytic enzymes (i.e., autolysins). The relationship between PBPs and autolysins is unclear, but it is possible that the beta-lactam antibiotic interferes with an autolysin inhibitor.      Antibiotic possesses activity against both Gram-positive and Gram-negative bacteria. The drug retains antibacterial activity in the presence of certain beta-lactamases, both penicillinase and cephalosporinase; however hydrolysis by other beta-lactamases, alteration of the PBP, and decreases permeability results in resistance to cefuroxime.

Indication of Antibiotics

For the treatment of many different types of bacterial infections such as bronchitis, sinusitis, tonsillitis, ear infections, skin infections, gonorrhea, and urinary tract infections.

  • Acute bacterial exacerbation of chronic bronchitis
  • Bacterial infections
  • Bloodstream infections
  • Bone and joint infections
  • Gonorrhea
  • Impetigo
  • Pneumonia
  • Urinary tract infection
  • Skin or soft tissue infection
  • Skin and structure infection
  • Septicemia
  • Meningitis
  • Joint infection
  • Osteomyelitis
  • Surgical prophylaxis
  • Tonsillitis/pharyngitis
  • Sinusitis
  • Intra abdominal infection
  • Appendicitis
  • Wound infection
  • Lower respiratory tract infection maxillary sinusitis
  • Otitis media bacterial
  • Skin and subcutaneous tissue bacterial infections
  • Pharyngitis
  • Bladder infection
  • Epiglottitis
  • Kidney infections
  • Otitis media
  • Peritonitis
  • Sepsis
  • Skin and structure /soft tissue  infection
  • Bacterial Infection
  • Bladder Infection
  • Acne
  • Bronchitis
  • Brucellosis
  • Bullous Pemphigoid
  • Chlamydia Infection
  • Ehrlichiosis
  • Epididymitis, Sexually Transmitted
  • Gonococcal Infection, Uncomplicated
  • Helicobacter Pylori Infection
  • Lyme Disease, Arthritis
  • Lyme Disease, Erythema Chronicum Migrans
  • Lyme Disease, Neurologic
  • Lymphogranuloma Venereum
  • Nongonococcal Urethritis
  • Ocular Rosacea
  • Ornithosis
  • Pelvic Inflammatory Disease
  • Pemphigoid
  • Pemphigus
  • Pneumonia
  • Psittacosis
  • Rheumatoid Arthritis
  • Rickettsial Infection
  • Syphilis, Early
  • Syphilis, Latent
  • Tertiary Syphilis
  • Upper Respiratory Tract Infection

Contra Indications of Antibiotics

  • History of severe hypersensitivity (e.g. anaphylactic reaction) to any other type of betalactam antibacterial agent (penicillins, monobactams and carbapenems).
  • Hemolytic anemia
  • Liver problems
  • Interstitial nephritis
  • Subacute cutaneous lupus erythematosus
  • Systemic lupus erythematosus
  • Antibiotic use should be avoided in pregnant or lactating women, and in children with developing teeth because they may result in permanent staining (dark yellow-gray teeth with a darker horizontal band that goes across the top and bottom rows of teeth), and possibly affect the growth of teeth and bones.
  • Usage during the first 12 weeks of pregnancy does not appear to increase the risk of any major birth defects. There may be a small increased risk for minor birth defects such as an inguinal hernia, but the number of reports is too small to be sure if there actually is any risk.

Side Effects of Antibiotics

The most common side effects 

More common

Rare

Drug Interactions of Antibiotic

Antibiotic may interact with following drugs, suppliments, & may change the efficacy of drugs

References

Patient safety assistant

Check your symptom safely

Hi, I am RX Symptom Navigator. I can help you understand what to read next and what warning signs need care.
Warning: Do not use this in emergencies, pregnancy, severe illness, or as a substitute for a doctor. For children or teens, use with a parent/guardian and clinician.
A rural-friendly guide: warning signs, when to see a doctor, related articles, tests to discuss, and OTC safety education.
1 Symptom 2 Severity 3 Safe guidance
First safety question

Is there chest pain, breathing trouble, fainting, confusion, severe bleeding, stroke-like weakness, severe injury, or pregnancy danger sign?

Choose quickly

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Start here: Write or select a symptom. The guide will show warning signs, doctor guidance, diagnostic tests to discuss, OTC safety education, and related RX articles.

Important: This tool is educational only. It cannot diagnose, treat, or replace a doctor. OTC information is not a prescription. In an emergency, contact local emergency services or go to the nearest hospital.

Doctor visit helper

Prepare before seeing a doctor

A simple rural-patient checklist to help you explain symptoms clearly, ask better questions, and avoid unsafe self-treatment.

Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Start with a registered doctor or the nearest qualified health center.

What to tell the doctor

  • Write when the problem started and how it changed.
  • Bring old prescriptions, investigation reports, and current medicines.
  • Write allergies, pregnancy status, diabetes, kidney/liver disease, and major past illnesses.
  • Bring one family member if the patient is weak, elderly, confused, or a child.

Questions to ask

  • What is the most likely cause of my symptoms?
  • Which danger signs mean I should go to hospital quickly?
  • Which tests are necessary now, and which can wait?
  • How should I take medicines safely and what side effects should I watch for?
  • When should I come for follow-up?

Tests to discuss

  • Vital signs: temperature, pulse, blood pressure, oxygen saturation
  • Basic physical examination by a clinician
  • CBC, urine test, blood sugar, or imaging only when clinically needed

Avoid these mistakes

  • Do not use antibiotics, steroid tablets/injections, or strong painkillers without proper medical advice.
  • Do not hide pregnancy, kidney disease, ulcer, allergy, or blood thinner use.
  • Do not delay emergency care when danger signs are present.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

  • Avoid heavy lifting, sudden bending, and prolonged bed rest.
  • Use comfortable posture and gentle movement as tolerated.
  • Discuss physiotherapy, X-ray, or MRI only when clinically needed.

OTC medicine safety

  • For mild back pain, pain-relief medicine may be discussed with a doctor or pharmacist.
  • Avoid repeated painkiller use if you have kidney disease, stomach ulcer, uncontrolled blood pressure, or are taking blood thinners.

Avoid these mistakes

  • Do not start antibiotics without a proper medical decision.
  • Do not use steroid tablets or injections casually for quick relief.
  • Do not delay emergency care because of home remedies.

Get urgent help if

  • Back pain with leg weakness, numbness around private area, loss of urine/stool control, fever, cancer history, or major injury needs urgent care.
Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Orthopedic / spine specialist, physical medicine doctor, or qualified clinician
Tests to discuss with doctor
  • Neurological examination for leg power, sensation, reflexes, and straight leg raise
  • X-ray only if injury, deformity, long-lasting pain, or doctor suspects bone problem
  • MRI discussion if severe nerve symptoms, weakness, bladder/bowel problem, or persistent symptoms
Questions to ask
  • What is the most likely cause of my symptoms?
  • Which warning signs mean I should go to emergency care?
  • Which tests are really needed now?
  • Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?
  • Is physiotherapy, posture correction, or activity modification needed?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Safe pathway to proper treatment

Back pain care roadmap

Use this simple roadmap to understand the next safe steps. It is educational and does not replace examination by a doctor.

Go to emergency care if you notice:
  • New leg weakness, numbness around private area, or loss of bladder/bowel control
  • Back pain after major injury, fever, unexplained weight loss, cancer history, or severe night pain
Doctor / service to discuss: Orthopedic/spine specialist, physical medicine doctor, physiotherapist under guidance, or qualified clinician.
  1. Step 1

    Check danger signs first

    If danger signs are present, seek emergency care and do not wait for online information.

  2. Step 2

    Record the symptom story

    Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.

  3. Step 3

    Visit a qualified clinician

    A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.

  4. Step 4

    Do only useful tests

    Discuss neurological examination first. X-ray or MRI may be needed only when red flags, injury, nerve weakness, or persistent severe symptoms are present.

  5. Step 5

    Follow up and return early if worse

    If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips
  • Take a written symptom diary and all previous prescriptions/test reports.
  • Do not hide medicines already taken, even herbal or over-the-counter medicines.
  • Ask which warning signs mean urgent referral to hospital.
  • Avoid forceful massage or bone-setting when there is weakness, injury, fever, or nerve symptoms.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.

RX Patient Help

Ask a health question safely

Write your symptom story. A health professional or site editor can review it before any answer is prepared. This box is not for emergency care.

Emergency first: Severe chest pain, breathing trouble, unconsciousness, stroke signs, severe injury, heavy bleeding, or rapidly worsening symptoms need urgent local medical care now.

Frequently Asked Questions

Is this article a replacement for a doctor?

No. It is educational content only. Patients should consult a qualified clinician for diagnosis and treatment.

When should I seek urgent care?

Seek urgent care for severe symptoms, rapidly worsening condition, breathing difficulty, severe pain, neurological changes, or any emergency warning sign.

References

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