Disclaimer
Allopathy medicine awareness article for doctors & hospitals.
Can't cover everything in this small article
Won't cover antivirals, Antifungals, Anthelminthic drugs here
Lots will remain unanswered
Not everyone will be happy
But everyone will take something home
All we can do is initiate a curiosity of research and understand what is wrong/right
Wordplay
Antibiotics
Antibacterial
Antimicrobial
Antiviral
Anthelminthic
Antifungal
Antibacterial
Case Discussion 1 -
A 55 year lady, was operated for hysterectomy 5 days back. She went home, started having fever 2 days back and now brought with altered sensorium, Low urine Output. On Examination, HR=130, Pulse Feeble BP=80/50 RR=38 SPO2 - 92% on air CVS - cold extremities CNS - Confused, drowsy
What do you think could have happened?
What is septicemia / Bacteremia?
What is sepsis?
What will you do?
Give Antibiotics?
Which one??
Likely Pathogens - Seek information from local Pathologist/Microbiologist Life is a constant fight against infection
Bacteria are all around us
Skin, Gut, Air, Soil, ….
But Bacteria is not always Bad
Gut bacteria
Problems with antibiotics
Harmful bacteria grow
Probiotics
Daralac, Sporolac, Curd, Vitamin B, etc.,
Normal vs C-Section babies exposure to mother's bacteria is different.
Why does infection occur?
Weakened defenses or hygiene problem
Pathogenic bacteria enter from other locations
Salmonella
Back to case discussion on Septicemic Shock
How Bacteria enters the body? - Portal of Entry
Skin
Upper Respiratory Tract
GI Tract
Urogenital Tract
Tubes and Punctures - including bites
Skin and Soft Tissue Infection SSTI
Skin, subcutaneous tissue, fascia, and muscle
Impetigo
Folliculitis
Furuncle
Carbuncle
Erysipelas
Cellulitis
Necrotizing Fascitis
Organisms causing skin and soft tissue infection
Gram Positive Cocci - Staphylococcus aureus
Streptococcus pyogens
Site specific - gram negative bacilli in Perianal abscess
Immunocompromised - pseudomonas, enterococcus
Classification of Bacteria
Cocci (ball) & Bacilli (rod)
Gram Positive (Changes to Purple) & Negative (Pink)
Aerobic (w/ O2) & Anaerobic (w/o O2)
Skin infections are usually Gram Positive Cocci
Empiric Therapy
There are hundreds of antibiotics
Why so many antibiotics needed?
Resistance, side effects, many new bacteria growth
How antibiotics work?
Most drugs act on patient, his organs, receptors
Antibiotic should be toxic to the bacteria but not to humans
Cell wall and Ribosome 70S are two things that differentiate bacteria from us.
Antibiotics that inhibit Cell Wall Synthesis
More than 60% antibiotics act by inhibiting cell wall synthesis
Beta Lactam Antibiotics
Glycopeptides
Penicillin
General structure of Penicillins
Beta-Lactam Ring -> Beta Lactamase -> enzymes -> Bacterias shared those enzymes
Doctors started Beta Lactamase Inhibitors
Amoxicillin + Clavulanic acid is used to treat certain infections caused by bacteria, including infections of the ears, lungs, sinus, skin, and urinary tract. Amoxicillin is in a class of medications called penicillin-like antibiotics. It works by stopping the growth of bacteria.
Piperacillin + tazobactam, sold under the brand name Zosyn among others, is a combination medication containing the antibiotic piperacillin and the β-lactamase inhibitor tazobactam. The combination has activity against many Gram-positive and Gram-negative bacteria including Pseudomonas aeruginosa
Unasyn (Ampicillin + Sulbactam) is a combination antibiotic medication containing ampicillin and sulbactam. It is used to treat a wide variety of bacterial infections -
meningococcal meningitis.
bacterial meningitis caused by Streptococcus.
infection of the biliary tract.
pneumonia caused by bacteria.
diverticulitis.
E. coli bacteria infection of abdominal cavity lining.
Klebsiella pneumoniae infection of abdominal cavity lining.
Cephalosporin
Skin infections - Gram +ve - Amoxicillin + Clavulanic acid (Gen 1, 2)
Intra abdominal / cepsis - Gram -ve - Piperacillin + tazobactam (Gen 3,4)
Upper Respiratory Tract
Nasopharyngeal infection
Sinusitis
Otitis media
Epiglottitis
Laryngitis
Tracheobronchitis
Pneumonia
Organisms causing URTI
Rhinoviruses
Coronaviruses
Adenoviruses
Coxsackieviruses
In general adult URTI is by these viruses, So don't give antibiotics. Administer steam, decongestant, anti-inflammatory, etc.,
8-10-12 age kids can get Gram Positive Cocci bacteria - Streptococcus. If not treated well it can turn into Rheumatic fever & Rheumatic heart disease. Amoxicillin / Co-amoxiclav / Ampicillin can be administered.
Non typeable H influenzae, and Moraxella catarrhalis
Lower Respiratory Tract
Pneumonia
Community acquired
Pneumonaiae, H.influenzae, Legionnella, E.coli, Klebsiella sp., S.aureus
Levofloxacin 500 OD (7 days)
Amoxycillin 500 - 1gm TDS
IV Mox-clav 1.2 gm TDS or Ceftriaxone 2 gm OD
Upgrade - (Escalate quickly, deescalate slowly)
Piperacillin Tazobactam
Meropenem
Cefoperazone sulbactam
MRSA is a doubt
Linezolid 600 IV / Oral BD
Atypical - Doxycline 100 BD or Azithromycin 500 OD
Hospital acquired
Entero-bacteriaceae, Pseudomonas spp., Acinetobacter spp. (Gram -ve)
Treatment
Piperacillin-tazobactam 4.5g IV q6h or Cefoperazone-sulbactam 3g IV q8h
Upgrade -
Imipenem 1g IV q8h or meropenem
Modify based on culture of lower respiratory secretions.
Antibiotics that inhibit Ribosome 50s Macrolides
More effective in Lung infections because they concentrate in Lung macrophages
Thromycin
Erythromycin
Azithromycin
Roxithromycin
Cidal and Static
Those antibiotics which kill the bacteria are bactericidal. E.g., Beta lactams, Floxacin
Those which inhibit the growth of bacteria without killing it are termed bacteriostatic
E.g., Doxycline, Macrolides
If patient has taken antibiotics in past 90 days, then we don't give static antibiotics.
GI Tract
Diarrhea
Intraabdominal infection
Parasitic infection
Salmonella
Acute Gastroenteritis
Viral
Enterotoxigenic E Coli
Treatment
Rehydration
No Antibiotics (unless Dysentery)
If Dysentery - Metronidazole, Nitazoxamide, Diloxanide Furate (for amoebic)
Ciprofloxacin 500 BD for bacillary dysentery
Enteric Fever / Typhoid
Cephalosporin
Oral - Cefixime 200 BD 14 days / Azithromycin 500 BC x 7 days
IV - Ceftriaxone 2 gm IV BD
Intra abdominal infections
Biliary tract infections (cholangitis, cholecystitis)
Spontaneous bacterial Peritonitis
Secondary peritonitis, Intra-abdominal abscess / GI perforation
Post necrotizing pancreatitis: infected pseudocyst; pancreatic abscess
Sick Patient, upgrade to -
Piperacillin/tazobactam 4.5 gm IV 8 Hrly
Addition of cover for yeast (fluconazole IV 800 mg loading dose day 1, followed by 400 mg 2nd day onwards)
Enterococcus (vancomycin / teicoplanin) may be contemplated
Gram Negative Bacteria (Bacilli - rods)
Enterobacteriaceae
E Coli
Klebsiella
Proteus
Shigella / Salmonella
Pseudomonas (It’s a monster. Administer: Piperacillin Tazobactam)
Severe
Meropenem 1 gm IV 8 hrly
Or
Imlpenem Cilastatin 500 mg IV 6 hourly
To cover Anaerobic - Metronidazole 400 8hrly IV
Antibiotics for Enterobacteriaceae
Third Generation Cephalosporins
Ceftriaxone 2gm IV OD
Cefoperazone Sulbactam
Fluoroquinolones
Floxacins
Anaerobic Bacteria
Clostridium
Peptostreptococcus
Bacteroids
Anaerobic Bacteria - Classification
Gram-negative bacilli (curved, spirals & spirochete forms) - Bacteroids, Borrelia, Butyrivibrio, Capnocytophaga, Campylobacter, Fusobacterium, Leptotrichia, Porphyromonas, Prevotella, Treponema, etc.,
Gram-positive cocci - Anaerococcus, Coprococcus, Micromonas, Peptococcus, Peptostreptococcus, Streptococcus, Gemella, etc.,
Nonsporing Gram-positive bacilli - Actinomyces, Arcanobacterium, Bifidobacterium, Eubacterium, Lactobacillus, Methanobacterium, Mobiluncus, Propionibacterium, etc.,
Gram-negative cocci - Acidaminococcus, Anaeroglobus, Veillonella
Anaerobic Bacteria coverage
Metronidazole / Tinidazole tab 400 mg / IV
For groin, vagina, belly region (abdomen and Genito-urinary tract) coverage
Clindamycin - C 150 mg
Any other region coverage than groin, belly region said for Metronidazole.
Suppresses protein synthesis by binding to 50S ribosomal subunits
Anaerobic Bacteria
Bite wounds
PID
Genitourinary Tract
Acute uncomplicated Cystitis
Acute uncomplicated Pyelonephritis
Enterobacteriaceae
Streptococcus saprophyticus
Choice of Antibiotics in Acute uncomplicated UTI
Levofloxacin 500 OD (not effective nowadays)
Nitrofurantoin 100 mg BD x 5 Days (old drug, sulpho based, first choice in US)
Bactrim DS (Cotrimoxazole)
Fosfomycin
Fosfomycin is a bactericidal, activity against several bacteria including multidrug resistant Gram-negative bacteria, by irreversibly inhibiting an early stage in cell wall synthesis.
Acute Cystitis
Multi-drug resistant UTI: 2-3 g PO every 2-3 days for 3 doses
Aminoglycosides - For Hospitalized UTI
Gentamycin
Amikacin
Piperacillin/tazobactam
Monitor renal function closely and rationalize according to culture report
Complete total duration of 14 days
Tubes and Punctures
Endocarditis
Vehicle borne diseases
If it is Tubes & Punctures, its Hospital related
Causative Organism - Pseudomonas (Gram-ve in immunocompromised patients, blue-green), Klebsiella, Enterococcus, MRSA
Piperacillin/tazobactam
Meropenem
Clindamycin
Vancomycin
Anti Pseudomonas
Antipseudomonal beta lactam
Piperacillin
Ceftazidime
Cefepime
Imipenem
Aztreonam
+
Aminoglycoside
Tobramycin
Gentamycin
Amikacin
or
Fluoroquinolones
Ciprofloxacin
Levofloxacin
MRSA (Gram +ve)
Antibiotics
Glycopeptides (Safegaurd these, as the bacteria can become sensitive to these kind)
Vancomycin
Gram +ve Cocci Staphylococcus, MRSA
Teicoplanin
Gram +ve Bacteria including Enterococcus, MRSA
Factors in choice of Antibiotics
Supposed causative organism
Spectrum of activity
Penetration in target tissues
Metabolism of antibiotic and interaction
Patient's overall condition
Route of administration
Timing of dosage - with food
Cidal or static
Bioavailability
Three types of antibiotic treatment
Prophylactic
The person is not infected yet but has high chances
HCQS
Pre operative Antibiotics
Cefazolin given before surgery to prevent a Staphylococcal skin infection of the surgical site
Empiric
Confirm or suspected infection but organism is not known. Culture takes time and money.
This is the most common type of treatment we do.
And this is what we learnt till now.
But then, you should know the causative organisms for common infections.
E.g.,
Levofloxacin initiated for a patient with presumed community-acquired pneumonia
Ceftriaxone given for the treatment of suspected pyelonephritis
Vancomycin, tobramycin, and meropenem for a patient with probable
Hospital-acquired pneumonia in the intensive care unit
Definitive
We know the organism and its sensitivity.
Choice is for safe, effective, cheap and narrowest spectrum possible
E.g.,
Transitioning from piperacillin/tazobactam to ampicillin in a patient with a wound infection caused by Enterococcus faecalis, which is susceptible to both drugs
Discontinuing ceftriaxone and initiating ciprofloxacin for a patient with a UTI caused by Klebsiella pneumoniae that is resistant to ceftriaxone but susceptible to ciprofloxacin
Take home messages
Not every infection needs antibiotics
If uncomplicated, start with narrowest spectrum
If very serious patient, start with maximum but slowly de-escalate
Overuse of Antibiotics is slowly making the world difficult to live…