Beta Lactum Antibiotics Question And Answers

Beta Lactum Antibiotics Important Notes

1. Beta lactam antibiotics are

• Penicillins
• Cephalosporins
• Monbactem
• Carbepenems

2. Penicillin

• Has a wide therapeutic range
• Is the safest drug
• Penicillin Classification
  • Natural – penicillin G, procaine penicillin, Benzathine penicillin
  • Acid resistance penicillin – penicillin V, phenoxy ethyl penicillin
  • Penicillinase resistance penicillin
    • Acid labile – methicillin, cloxacillin, nafcillin
    • Acid resistant – fucloxacillin
  • Broad spectrum penicillin – ampicillin, amoxicillin, talampicillin
  • Extended-spectrum penicillin – carbenicillin, ticarcillin
  • Beta-lactamase inhibitors – augmentin, sulbactam
• Penicillin Adverse effects
  • Anaphylaxis
  • Angioedema
  • Superinfection
  • JarischHerxheimer reaction
• Penicillin Uses
• • Syphilis
  • Actinomycosis
  • Gonorrhoea
  • Streptococcal infection
  • Abscess
  • Cellulitis

3. Carbenicillin

• It is neither Penicillinase resistance nor acid resistance
• It is inactive orally
• Rapidly excreted in urine
• It is active against pseudomonas aeruginosa and indole positive proteus

4. Benzathine penicillin

• It is a long-acting drug
• Given every 2-4 weeks
• Remains effective for prophylactic purposes for up to 4 weeks

5. Drugs and their route of administration

6. Cephalosporins

• They have a 7-amino cephalosporins acid nucleus which bears a close resemblance to the 6-APA nucleus of penicillin.
• They are effective against both gram +ve and gram -ve organisms
• They inhibit bacterial cell wall synthesis
• Doesn’t undergo any metabolism in the body except cefotaxime
• Excreted by kidneys except for cefoperazone
• Generations:.

Read And Learn More: Pharmacology Question and Answers

Beta Lactum Antibiotics Long Essays

Question 1. Define antibiotic. Classify penicillin. Explain their mechanism of action, toxicity, and uses of penicillin G or Benzylpenicillin.
Answer:

Antibiotics:

These are substances produced by micro-organisms that selectively suppress the growth or kill other micro-organisms at very low concentrations.

Penicillin:

Penicillin is a beta-lactam antibiotic.

Penicillin Classification:

1. Natural penicillin – penicillin G.

2. Semi-synthetic penicillin

• Acid resistant – penicillin V.
• Penicillinase-resistant penicillin.
  • Methicillin, cloxacillin.
• Extended-spectrum penicillin.
  1. Aminopenicillin – Ampicillin, Bacampicillin.
  2. Carboxypenicillin – Carbenicillin, Ticarcillin.
  3. Ureidopenicillin – peperacillin, mezlocillin.

Penicillin Mechanism of action:

• Bacterial cell walls consist of peptidoglycan chains.
• These require transpeptidase enzymes.

Penicillin Toxicity:

• Pain and sterile abscess at the site of injection.
• Thrombophlebitis on IV injections.
• Hypersensitivity reactions.
  • Frequently rashes, itching, urticaria, and fever occurs.
  • Rarely wheezing, angioneurotic edema, serum sickness, and exfoliative dermatitis occur.
• Topical use of penicillin causes contact dermatitis.
• CNS effects – include confusion, muscle twitchings, convulsions, and coma.
• Suprainfections – occur rarely due to the narrow spectrum of activity of penicillin.
• Jarisch – Herxheimer reaction.
• When penicillin is injected into a syphilitic patient; there is sudden destruction of spirochaetes and release of its toxic products known as the Jarisch herxcheimer reaction.
• It is characterized by fever, myalgia, shivering, exacerbation of syphilitic lesions, and vascular collapse.

Penicillin Uses:

1. Therapeutic uses

• CO Orodental infections – caused by aerobic and anaerobic micro-organisms.
• Pneumococcal infections – like pneumonia, meningitis, and osteomyelitis.
• Streptococcal infections – like pharyngitis, sinusitis, pneumonia, meningitis.
• Meningococcal infections.
• Staphylococcal infections.
• Syphilis.
• Diphtheria.
• Anaerobic infections – like pulmonary, periodontal, and brain abscesses.
• Actinomycosis.
• Tetanus, gas gangrene, anthrax, trench mouth, rat-bite fever.

2. Prophylactic uses

• To prevent recurrence of rheumatic fever.
• Prevent sexually transmitted diseases like gonorrhea and syphilis.
• Surgical prophylaxis.
• To protect against agranulocytosis.

Question 2. Describe the antibacterial spectrum and therapeutic uses of ampicillin.
Answer:

Ampicillin:

It is semisynthetic aminopenicillin.

Antibacterial spectrum:

1. Cocci-strep viridians, enterococci, penumococci, gonococci, meningococci.
2. Gram negative bacilli – H.influenza, E.coli, proteus, salmonella, shigella.

Ampicillin Uses:

• Urinary tract infections.
• Respiratory tract infections like bronchitis, sinusitis, and otitis media.
• Meningitis.
• Gonorrhoea.
• Bacillary dysentery.
• Typhoid fever.
• Cholecystitis.
• Subacute bacterial endocarditis.
• Septicaemia.
• Orodental infections.

Question 3. Write the treatment of penicillin in anaphylactic shock.
Answer:

Treatment of Anaphylactic Shock:

• Penicillin causes anaphylactic reactions.
• It is more common following parenteral administration than oral.
• So the history of penicillin allergy must be elicited before injection.
• A scratch test or intradermal test with 2-10 units may be performed first
• Treatment of anaphylactic shock is as follows.
• Put the patient in a reclining position.
• Administer oxygen.
• Perform cardiopulmonary resuscitation.
• Inject adrenaline 0.5 mg IM, repeat every 5-10 min or adrenaline diluted 1:10000 or 1:1,00,000 IV.
• Administer chlorpheniramine 10 – 20 mg IM.
• IV hydrocortisone succinate 100 – 200 mg.

Question 4. Define chemotherapeutic agents. Describe newer penicillins.
Answer:

Chemotherapeutic agents:

A chemical of natural or synthetic origin used for its specific action against disease, usually against infection is called a chemotherapeutic agent.

Newer penicillins:

It includes:

1. Acid-resistant penicillin – phenoxymethyl penicillin – penicillin V.

2. Penicillinase-resistant penicillin – methicillin, cloxacillin.

3. Extended-spectrum penicillins

• Aminopenicillin – Ampicillm, Bicampicillin.
• Carboxypenidllm – carbenicillin, ticarcillin.
• UreidopenidlJin – piperacillin.

4. P-Lactamase inhibitors

Clavulanic acid, sulbactam.

Newer penicillins AIMS:

• To overcome the disadvantages of penicillin G like.
• Poor oral efficacy.
• Susceptibility to penidllanse
• Narrow spectrum
• Hypersensitivity reactions.
• p-lactamase inhibitors.

Question 5. Classify Penicillins. Write the spectrum of action, mechanism of action, therapeutic uses, and adverse effects of Amoxicillin.
Answer:

Penicillin Classification:

• Natural – penicillin G, procaine penicillin, Benzathine penicillin.
• Acid resistance penicillin – penicillin V, phenoxy ethyl penicillin
• Penicillinase resistance penicillin
  • Acid labile – methicillin, cloxacillin, nafcillin
  • Acid resistant – fucloxacillin
• Broad spectrum penicillin – ampicillin, amoxicillin, talampicillin
• Extended-spectrum penicillin – carbenicillin, ticarcillin
• Beta-lactamase inhibitors – augmentin, sulbactam

Amoxicillin:

It is aminopenicillin

Amoxicillin Spectrum Of Action:

• Cocci – streptococcus viridians, enterococci, pneumococci, gonococci, meningococci
• Gram negative bacteria – E.coli, proteus, salmonella

Amoxicillin Mechanism Of Action:

• The bacterial cell wall consists of peptidoglycan chains
• These require transpeptidase enzymes
• Penicillin inhibits transpeptidase → which inhibits the synthesis of peptidoglycan → results in the formation of cell wall deficient bacteria → causes lysis bacteriocidal

Amoxicillin Uses:

• Typhoid
• Respiratory infections
• Urinary tract infection
• Gonorrhoea
• Subacute bacterial endocarditis
• The most commonly used antibiotics for dental use
• Drug of choice for prophylaxis for endocarditis

Amoxicillin Adverse Effects:

• Adverse effects are rare
• Diarrhea – due to irritation of the lower part of the intestine and alteration of bacterial flora
• Skin rashes

Beta Lactum Antibiotics Short Essays

Question 1. Adverse effects of penicillin.
Answer:

1. Penicillin Hypersensitivity reactions

• It is the more common adverse effect of penicillin.
• Frequent manifestations are – rashes, itching, urti- cariaand fever.
• Rarely wheezing, angioneurotic edema, serum sickness, and exfoliative dermatitis occur rarely.
• An anaphylactic reaction may rarely occur but may create a serious problem.
• Adrenaline injection is kept loaded to treat anaphylaxis.
• It is more common with parenteral administration than oral.
• To prevent it, a history of penicillin allergy is elicited.
• A scratch test or intradermal test with 2-10 units is done before the use of penicillin.

2. Penicillin Local effects

• Pain – at the site of injection
• Nausea – on oral ingestion.
• Thrombophlebitis – on IV injection occurs.

3. Penicillin CNS effects

• Large doses cause mental confusion, muscular twitching convulsions, and coma, especially in patients with renal insufficiency IV infections.

4. Penicillin Jarlsch – Herxheimer miction

• It occurs when penicillin is injected into a syphilitic patient
• It is due to the release of endotoxins from dead organisms.
• It is due to the release of endotoxins from dead organisms.
• It is characterized by shivering, fever, myalgia, exacerbation of lesions, and vascular collapse.
• It lasts for 12 – 72 hours.
• Aspirin and corticosteroids provide symptomatic relief.

5. Penicillin Superinfections

It occurs rarely due to a narrow spectrum of activity.

Question 2. Uses of benzylpenicillin (PnG).
Answer:

1. Orodental infections

• Parenteral penicillin is more effective.
• It is given at ordinary doses of 0.5 – 2 MU IM-6 hourly in cases of periodontal abscess, periapical abscess, pericoronitis, ANUG, oral cellulitis, etc.

2. Streptococcal infections

• 0.5 – 5 MU IV 8 hourly for 7-10 days given for pharyngitis, otitis media, scarlet fever, and rheumatic fever.
• High doses of 10 – 20 MU IV daily for 2 – 6 weeks are used in subacute bacterial endocarditis.

3. Pneumococcal infections

If the organism is sensitive, PnG 3-6 MU IV every 6 hours is used.

4. Meningococcal infections

High doses are needed.

5. Gonorrhoea

6. Penicillin

• Early and latent syphilis – 1.2 MU of procaine penicillin daily for 10 days.
• Late syphilis – 2.4 MU of benzathine penicillin weekly for 4 weeks.

7. Diphtheria – 1 – 2 MU procaine penicillin daily for 10 days

8. Tetanus and gas gangrene – 6 – 12 MU dialy.

9. Anthrax – 4 MU 6 hourly for 2 weeks.

10. Actinomycosis – 2 – 4 MU IV 6 hourly for 4 weeks.

Benzylpenicillin Prophylactic use:

• Penicillin G is used «s prophylactic In.
  • Rheumatic fever
  • Gonorrhoea and syphilis
  • Valvular heart disease
  • Surgical procedures.
  • Agranulocytosis.

Question 3. Extended-spectrum penicillin.
Answer:

1. Amlnopenicillin – Amptclllln, Bacamplclllln, Amoxicillin
2. Carboxypenicillin – Carbenicillin, Ticarcillin
3. Ureidopenicillin -Piperacillin, Mezlocillin.

Extended-spectrum penicillin Uses:

Amlnopenicillin – Urinary tract Infection

• Respiratory tract infection
• Dental infections > Meningitis
• Typhoid
• Septicaemia
• Gonorrhoea
• Bacillary dysentery
• Cholecystitis
  • Carboxypenicillin – Used as sodium salt.
  • In serious infections like burns, septicemia
  • Ureidopenicillin – In gram-negative infections
  • caused in immunocompromised patients

Extended-spectrum penicillin Adverse effects:

• Aminopenicillin – Diarrhoea, skin rashes
• Carboxypenicillin – Edema, CLF, bleeding
• Ureidopenicillin – Relatively safe.

Question 4. Penicillins act as bacteriocidal agent.
Answer:

Penicillin inhibits the synthesis of bacterial cell walls.

It is more lethal in the phase of rapid multiplication when cell wall synthesis takes place.

Penicillins act as bacteriocidal agent Mechanism:

Penicillin also depresses bacterial autolysins which usually function during bacterial cell division.

Question 5. Cloxacillin and staphylococcal infections.
Answer:

Cloxacillin is penicillinase-resistant penicillin.

• It is resistant to hydrolysis by penicillinase produced by bacteria.
• It is also acid resistant
• It is more active against penicillinase-producing staphylococci.
• It is incompletely absorbed from the oral route especially when taken on an empty stomach.
• It is more than 90% plasma bound.
• The plasma half-life is 1 hour.
• It is given in doses of 0.25 – 0.5 g orally 6 hourly.

Question 6. Cephalosporins.
Answer:

Cephalosporins are semisynthetic antibiotics with a beta-lactam ring.

They have a wider spectrum of activity.

Cephalosporins Classification:

1. Cephalosporins First generation

• Parenteral – cephalothin, cefazolin.
• Oral – cephalexin, cefadroxil.
  • They are very effective against gram-positive organisms and less against gram-negative.

2. Cephalosporins Second generation

• Parenteral – cefamandole, cefuroxime.
• Oral-cefachlor.
  • They are more active against gram-negative or, paganism and some are active against anaerobes

3. Cephalosporins Third generation

• Parenteral – cefotaxime, ceftriaxone.
• Oral – cefixime.
  • They are highly resistant to beta-lactamase.
  • Have good activity against gram-negative organisms.
  • They are rarely used in dentistry.

4. Cephalosporins Fourth generation

• Parenteral – cefepime, cefpriome.
• Active against gram-positive and gram-negative organisms.
• More resistant to b-lactamases.
• Used in septicemia, nosocomial, and in infections in immune-compromised patients.

Cephalosporins  Adverse reactions

• Pain at the site of injection.
• Hypersensitivity reactions.
• Nephrotoxicity.
• Bleeding diarrhoea
• Neutropenia – low WBC count
• Disulfiram-like reaction with alcohol.

Cephalosporins Uses:

• Dental infections.
• Used as an alternative to penicillin.
• Urinary, respiratory, and soft tissue infections.
• Surgical prophylaxis.
• Gonorrhoea
• Meningitis
• Septicaemia.
• Typhoid.
• Mixed aerobic – anaerobic infections.
• Nosocomial or hospital-acquired infections
• Prophylaxis and treatment of infections in neutropenic patients.

Question 7. Semi-synthetic penicillin.
Answer:

Semi-synthetic penicillin Classification:

1. Acid-resistant penicillin – Penicillin V

2. Penicillinase-resistant penicillin – methicillin, clock- oxacillin.

3. Extended-spectrum penicillin.

• Aminopenicillin – ampicillin, amoxicillin.
• Carboxypenicillin – carbenicillin, ticarcillin.
• Ureidopenicillin – peracillin.

4. p-lactamase inhibitors.

• Clavulanic acid, sulbactam.

Semi-synthetic penicillin Advantages over natural penicillin:

• Effective orally.
• Have a wider spectrum of activity
• Resistance to b-lactamases
• Hypersensitivity reactions are less.

Question 8. Compare amoxicillin and ampicillin.
Answer:

Question 9. 3r^d generation cephalosporins.
Answer:

• They are highly resistant to beta-lactamase
• Active against Gram-negative and pseudomonas
• Less active against Gram-positive and anaerobes

3r^d generation cephalosporins Example

Question 10. Amoxicillin.
Answer:

It is aminopenicillin

Amoxicillin Spectrum of Action:

• Cocci – streptococcus viridians, enterococci, pneumococci, gonococci, meningococci
• Gram negative bacteria – E.coli, proteus, salmonella

Amoxicillin Mechanism of Action:

• The bacterial cell wall consists of peptidoglycan chains
• These require transpeptidase enzymes
• Penicillin inhibits transpeptidase → which inhibits the synthesis of peptidoglycan → results in the formation of cell wall deficient bacteria → causes lysis → bacteriocidal

Amoxicillin Uses:

• Typhoid
• Respiratory infections
• Urinary tract infection
• Gonorrhoea
• Subacute bacterial endocarditis
• The most commonly used antibiotics for dental use
• Drug of choice for prophylaxis for endocarditis

Amoxicillin Adverse Effects:

• Adverse effects are rare
• Diarrhea – due to irritation of the lower part of the intestine and alteration of bacterial flora
• Skin rashes

Beta Lactum Antibiotics Short Question And Answers

Question 1. Probenecid and penicillin are used in chemotherapy.
Answer:

Probenecid is combined with penicillin because.

• Probenecid competes with penicillin for active tubular secretion.
• Retards their excretion.
• Increases plasma concentration of penicillin.
• Increases duration of action of penicillin. Thus, this combination is used in.
  • Treatment of bacterial endocarditis.
  • Gonococcal infections.

Question 2. Uses of benzylpenicillin or Penicillin G.
Answer:

1. Therapeutic uses:

• Orodental infections.
• Pneumococcal infections.
• Streptococcal infections.
• Meningococcal infections
• Staphylococcal infections
• Syphilis
• Diptheria
• Anaerobic infection
• Actinomycosis.
• Tetanus and gas gangrene.

2. Prophylactic uses.

• Rheumatic fever.
• Agranulocytosis
• Sexually transmitted diseases like syphilis and gonorrhea
• Surgical prophylaxis.

Question 3. The rationale for combining amoxicillin and clavulanic acid. Write one indication of this combination.
Answer:

Ciavulanic acid has a beta-lactam ring but no antibacterial activity.

• The combination of amoxicillin and clavulanic acid causes:
• Extension of the antibacterial spectrum.
• Inhibits beta-lactamase-producing organisms.
• After binding to the b-lactamase enzyme, clavulanic add itself gets inactivated, hence it is called a sudden inhibitor.

Amoxicillin and clavulanic acid Indications:

• Skin and soft tissue infections.
• Urinary tract infections.
• Respiratory tract infections.
• Orodental infections.
• Nosocomial infections.
• Gonorrhoea.

Question 4. D-penicillamine.
Answer:

D-penicillamine is a copper-chelating agent

D-penicillamine Uses:

• As chelating agent
• Use in rheumatoid arthritis.

D-penicillamine Adverse effects:

• Loss of taste.
• Systemic lupus erythematosus.
• Myasthenia gravis.

Question 5. Amoxicillin.
Answer:

Amoxicillin is a semi-synthetic penicillin.

Advantages over ampicillin:

• Good oral absorption.
• Food does not interfere with absorption.
• Diarrhea and skin rashes are less.

Amoxicillin Uses:

• Typhoid
• Respiratory tract infections.
• Urinary tract infections.
• Gonorrhoea.
• Subacute bacterial endocarditis.

Question 6. Adverse effects of penicillin.
Answer:

• Hypersensitivity reaction.
• Pain at the site of injection.
• Superinfection.
• CNS effects – hallucination, coma.
• Jewish Herxheimer reactions.

Question 7. β-lactamase inhibitors.
Answer:

Beta-lactamase inhibitors are the drugs that bind to inactive β-lactamases preventing the destruction of the β-lactam antibiotics.

Beta-lactamase inhibitors:

1. Clavulanic acid

• Competitively and irreversibly inhibits b-lactamases.
• It is a progressive inhibitor.
• It is combined with amoxicillin and ticarcillin.

2. Sulbactam

• It is combined with ampicillin.
• It is given parenterally for mixed aerobic-anaerobic infections.

3. Tazobactum

It is combined with piperacillin for parenteral administration.

Question 8. Why penicillin is not combined with sulphonamide?
Answer:

Penicillin is bacteriocidal while sulphonamide is bacteriostatic.

• Sulphonamide retards the multiplication of bacteria.
• Penicillin acts on actively multiplying bacteria.
• Thus combining penicillin and sulphonamide causes antagonism instead of synergism of both drugs.
• Hence, penicillin is not combined with sulphonamides.

Question 9. Amoxicillin.
Answer:

It is aminopenicillin

Cefixime Mechanism of Action:

• The bacterial cell wall consists of peptidoglycan chains
• These require transpeptidase enzymes
• Penicillin inhibits transpeptidase → which inhibits the synthesis of peptidoglycan → results in the formation of cell wall deficient bacteria → causes lysis → bacteriocidal

Cefixime Uses:

• Typhoid
• Respiratory infections
• Urinary tract infection
• Gonorrhoea
• Subacute bacterial endocarditis
• The most commonly used antibiotics for dental use
• Drug of choice for prophylaxis for endocarditis

Cefixime Adverse Effects:

• Adverse effects are rare
• Diarrhea – due to irritation of the lower part of the intestine and alteration of bacterial flora
• Skin rashes

Question 10. Cefixime.
Answer:

• It is third generation cephalosporin
• Highly resistant to beta-lactamase
• Have good activity against gram-negative organisms
• Less active against Gram-positive and anaerobes
• Rarely used in dentistry
• Given orally.
• Dose: 200-400 mg BD
• Plasma half-life – 3 hours

Cefixime Uses:

• Respiratory infections
• Biliary infections
• Urinary infections
• Adverse effects
• Stool changes
• Diarrhea