Antimicrobial Drugs Flashcards
Egs of diaminopyrimidines (2)
Trimethoprim
Pyrimethamine
Egs of nitrobenzene
Chloramphenicol
Egs of lincosamide (2)
Lincomycin
Clindamycin
Egs of glycopeptide (2)
Vancomycin
Teicoplanin
Nicotinic acid derivatives (3)
Isoniazid
Pyrizinamide
Ethambutol
Oxazolidinone eg
Eg of polypeptide (3)
Linezolide
Polymixin B
Colistin
Bacitracin
Eg of polyene (2)
Nystatin
Amphotericin B
Antibiotics obtained from fungi (3)
Penicillin, cephalosporin, griseofulvin
Antibiotics obtained from bacteria (3)
Polymixin B , Colistin, Bacitracin
Antibiotics obtained from actinomycetes (4)
Aminoglycosides
Tetracyclines
Macrolide
Chloramphenicol
Antibiotics with narrow spectrum of activity (3)
Penicillin G, streptomycin, erythromycin
Antibiotics with broad spectrum of activity (2)
Tetracycline
Chloramphenicol
What are the gram + cocci? (3)
Staphylococcus
Streptococcus
Enterococci
Gram -ve cocci (2)
Neisseria
Moraxella
What are the gram +ve rods ?
Actinomycetes
Bacillus
Clostridium
Diphtheria
Listeria monocytogenes
Antibiotics that become bactericidal at high concentrations (2)
Erythromycin
Nitrofurantoin
Antibiotics that inhibit cell wall synthesis are all ……
Another one that is bactericidal
Bactericidal
Those that cause leakage from cell membrane : polypeptides
Polyenes
Azoles
Those that inhibit protein synthesis are all ……except ……
Bacteriostatic
Except: aminoglycosides , streptogramin
Bactericidal
Short acting sulfonamides (4)
Diazine
Methizole
Oxaxole
Cysteine
Intermediate acting sulfonamide
Long acting sulfonamides
Sulfamethoxazole
Doxine
Methopyrazine
Topical sulfonamides
Sulfaacetamide sodium
Silver sulfadiazine
Mefetide
For RA and UC
Sulfasalazine
MOA of cotrimoxazole
PABA ——-> DHFA———THFA
FS. DHFR
Sulfonamide. Trimethoprim
Sulfonamide is a ……..inhibitor of PABA
Competitive inhibitor
Uses of sulfonamides
When combined with pyrimethamine
—resistant malaria, toxoplasma
When combined with cotrimoxazole
—SEPTRAN
STD: chanchroid, LGV
Enteritis: ecoli, shigella
P.carini, P.jejuni
Typhoid
Respiratory tract infection
Acute UTI
Nocardia
Adverse effects of sulfonamides
ABC of RASH
Aplastic anemia
Bilirubin displacement
Crystalluria
Rash
Acetylation
SLE
Hemolysis in G6PD
Adverse effects of trimethoprim
- N/V/ stomatitis
2 megaloblastic anemia - Pancytopenia
- Hyperkalemia
- Teratogenicity
MOA of dapsone
Structurally related to sulfonamides
Inhibits dihydroopeterate synthase
Prevents folic acid synthesis
First drug of nalidixic acid
Fluoroquinolones
Benefits of FQ (5)
- Highest potency
- Expanded spectrum
- Slow resistance
- Better toleratibilty
- Better tissue penetration
Classification of FQ
1st generation: gram -ve activity
nalidixic acid, oxalidinic acid
2nd generation: extended gram -ve activity
Norflox, lomeflox, ciproflox, oflox
3rd generation: gram -ve,gram+ve
Levoflox, spatiflox,gatiflox,peflox
Temaflox, tosiflox, moxiflox
4th generation: gram -ve,gram +ve, anerobes
Trova, sita, clina, gami,pruli, flero
Uses of FQ
4G SPECTRUM CT
4G: gonorrhoea,gynecological,gram -ve,,GI
S: septicemia
P: prophylaxis
E: enterocolitis
C: chanchroid
T: typhoid
R: resp tract
U: UTI
M: meningitis
C: conjunctivitis
T: Tb
Adverse effects of FQ (6)
- GIT: n/v/stomatitis
- CNS: due to GABA antagonist
Sleep disturbance,mood disturbances, headaches,seizures - CVS: Torsades de pointes: long Qt prolongation
Sparflox, gati,moxiflox - Phototoxic: lome >spar>peflox
- Bone and soft tissue:
Tendinitis, tendon rupture - Teratogenic
Most potent FQ
Least potent FQ
Ciprofloxacin
Norflox
Ciplox should not be taken with ….
FQ have low……
Food- as it delays absorption
CSF and aqueous level
FQ is ……
Peflox-use
Less active at acidic Ph
Meningeal infection- good CSF permiability
FQ with highest oral bioavailability
FQ with lowest oral bioavailability
Levoflox
Norflox
Drug with max plasma protein binding
Drug with highest first pass metabolism
Sparflox
Peflox
Longest acting FQ
FQ most potent against T.b
Sparflox
Moxiflox
What drug should not be given with FQ?
Elimination of Sparflox
NSAIDS- enhance CNS toxicity
Theophylline- ciplox and peflox increase toxicity
50% renal, 50% liver
FQ metabolized in liver (5)
Trova
Moxi
Peflox
Grepo
Nalidixic acid
Withdrawn from market coz of :
1. Temafloxacin
2. Grepafloxacin
- Immune hemolytic anemia
- Cardiotoxic
Withdrawal from market
3. Trovafloxacin
- Clinafloxacin
- Hepatotoxicity
- Phototoxcity
Gatiflox removed from market coz of ….
Hyperglycemia in elderly
MOA of FQ
Direct nucleic acid inhibitor
Inhibit DNA gyrase ( A subunit) in gram -ve
Inhibit topoisomerase 4: in gram +ve
DOC for anthrax
Most commonly used drug for diarrhoea
Ciprofloxacin
Ciprofloxacin
What is nalidixic acid ?
Non fluorinated quinolone used to rx UTI
MOA of Nitrofurantoin
Blocks acetyl CoA synthesis in bacterial carbohydrate metabolism
Used as urinary antiseptic in UTI
Why are aminoglycosides called so?
Coz they have amino groups linked glycosidically to >_2 amino sugar
Classification of aminoglycosides
Systemic: TANGSS KP
Tobramycin
Amikacin
Netilmicin
Gentamicin
Streptomycin
Sisomycin
Kanamycin
Paromomycin
Topical aminoglycosides
Neomycin
Framycetin
Egs of Ototoxic drugs (5)
- Aminoglycosides
- Furosemide
- Vancomycin
- Cisplatin
- Amphotericin B
Egs of nephrotoxic drugs (4)
Aminoglycosides
Amphotericin B
Cisplatin
Cyclosporine
MOA of aminoglycosides
Inihibition of initiation of protein synthesis and misreading of mRNA code
Spectrum of activity of Aminoglycosides
Only gram -ve bacteria.
Need oxygen for penetration, so not active in anerobes.
Aminoglycosides useful in bowel surgery
Neomycin
Dosage of aminoglycosides
Gentamycin , tobramycin ,siso,netilmycin
3- 5mg/kg/day
Streptomycin, amikacin : 7.5-25mg/kg/day
Aminoglycosides given for intestinal amibiasis and tapeworm
Paromycin
Most commonly used aminoglycosides
Sisomycin is similar to ….
Gentamycin
Gentamycin
Max activity of tobramycin is against …..org
……is no longer used due to toxicity
Pseudomonas
Kanamycin
Aminoglycosides useful against MRSA
Use of spectinomycin
Arbekacin
Rx of gonorrhoea in penicillin allergy patients
Aminoglycosides with widest spectrum
Topical ointments
Amikacin
Neomycin
Framycetin
Uses of paromycin (5)
Protozoal parasites:
Entameoba histolytica
Trichomonas vaginalis
Giardia lamblia
Cryptosporidium
Leishmania
Side effects of aminoglycosides
ONN HT
Ototoxicity
Nephrotoxicity
Neurotoxicity
Hypersensitivity
Teratogenic
Most vestibulotoxic AG
Most cochleotoxic
Streptomycin
Amikacin
Most nephrotoxic aminoglycosides
Least nephrotoxic aminoglycosides
Neomycin
Streptomycin
Maximum neuromuscular blockade
Streptomycin
Dosing sequence of AG
3 equal parts ( slowly over 60 mins) iv , every 8 hours
Dosing of Gentamycin as per renal clearance
> 70ml/min: 70% daily
50ml/min: 50% daily
30ml/min: 30% daily
20- 30ml/min: 80% on alternate days
10-20ml/min: 60% on alternate days
<10ml/min: 40% on alternate days
Why are macrolides called so?
Coz they have a big macro ring with attached sugars
Egs of macrolides
SET CAR
Spiramycin
Erythromycin
Tacrolimus
Clarithromycin
Azithromycin
Roxithromycin
Erythromycin is acid …….. hence given in …..form
Erythromycin undergoes …….circulation
Labile
Enteric coated form
Enterohepatic circulation and is excreted in bile
Erythromycin obtained from ……
Antibacterial spectrum of erythromycin
Streptomycetes erythreus
Gram +cocci
Gram -ve cocci
Gram + bacilli
MOA of erythromycin
Inhibit protein synthesis by inhibiting transfer of amino acids from A site to P site in 50S ribosome
It is bacteriostatic
Erythromycin can cause Qt prolongation if given along with: (3)
Astemizole
Terfenadine
Cisapride
Adverse effects of erythromycin
MACRO
Motilin receptor agonist
Allergy
Cholestasis
RO : Reversible ototoxicity
Cholestasis jaundice occurs …..days after Rx with erythromycin
Sms of cholestatic jaundice
10-20 days after therapy
Nausea,vomiting, abdominal cramps, jaundice, fever
Incidence of cholestatic jaundice is higher in ……
Uses of erythromycin
Pregnant women
C3LAW
Chancroid
Campylobacter
Corynebacterium
Legionella
Atypical pneumonia
Whooping cough -Bordetella pertusis
Erythromycin is DOC for ….(2)
Mycoplasma atypical pneumonia
Whooping cough
Azithromycin is DOC for ….(2)
Legionella
Chlamydia trachomatis
Clarithromycin is first line drug for ….
MAC
……, and ……macrolide inhibit CYP3A4 enzyme
This increases serum concentration of …… and ……
Erythromycin
Clarithromycin
Theophylline
Oral coagulants
MOA of lincosamides
What are the lincosamides ?
Similar to macrolides
Lincomycin
Clindamycin
Uses of clindamycin
- DOC for topical acne Rx
- DOC for bacteroids fragilis
- Clindamycin-pyrimethamine: T gondi
- Clindamycin + primaquine= P. Jejuni
S/e of clindamycin
Diarrhea
Pseudomembraneous colitis
Eg of ketolides what are they?
Telithromycin
Semisynthetic derivative of erythromycin having 3 keto group
Indication of telithromycin
Macrolide resistant community acquired pneumonia
MOA of linezolid
Spectrum of linezolid
Same as macrolides
Gram + pathogen only
Linezolid uses (3)
Rx for VRSA,MRSA
Diabetic foot
S/e of linezolid (3)
Myelosuppression
Optic neuropathy
Inhibit MAO- cheese reaction with tyrosine containing food
Streptogramins are in ratio :
Quintupristin: dalfopristin= 30:70
Adverse effect of streptogramin
Iv only
Arthralgia- myalgia syndrome
Polymixin B and colistin are given only topically why?
Asss with nephrotoxicity and neurotoxicity when given systemically
Mupirocin is obtained from: …..
Given….
Pseudomonas flutoscens
Topically
2% topical ointment for staph, strept- impetigo, folliculitis etc is …..
Retapamulin
Fusidic acid MOA, use
Inhibit protein synthesis
Use: topical
Non antibiotic use of erythromycin (2)
- Motilin receptor agonist : dm gastroparesis
- Anti I.F effect : arthritis
MOA of tetracycline
Inhibition of new amino acetyl tRNA at A site of 30S ribosomes
It is bacteriostatic
Why are tetracyclines called so?
Obtained from …..
Coz they have 4 benzene rings
Actinomycetes
Classification of tetracyclines
Gp1: t1/2: 6-10 hrs
Tetracycline, chlortetracycline,o a cyclone
Gp2: t1/2: 12-13 hrs
Demeclocycline, lymecycline
Gp3: t1/2: 18-20 hrs
Doxycycline, minocycline
Resistance to tetracycline (3)
- Decrease influx, increase efflux
- Creating ribosomal protein cover-to decrease entry
- Creating tetracycline inactivating enzyme.
Uses of tetracyclines
VACUM The BedRoom
Vibrio
Acne
Chlamydia
Ureaplasma
Mycoplasma
Typhoid
Borellia
Rickettsia
Food retards absorption of all tetracycline except (2)
Doxycycline and minocycline
All tetracycline should be reduced in renal failure except ……
Doxycycline
Use of demeclocycline
Use of minocycline (3)
Rx of SIADH
Swimming pool granuloma caused by M.marinum
Topically acne, periodontitis
Adverse effects of tetracyclines
LK ADVI is PT Teacher
Liver damage
Kidney damage - except doxycycline
Antianabolic effect
D.I - demeclocycline
Vestibular toxicity: minocycline
Increased ICP
Phototoxic: with demeclocycline and doxycycline
Teeth and bone discoloration
Teratogenic
How does tetracycline cause teeth discoloration?
Tetracycline not given below ……yrs of age
By forming calcium tetracycline chelates and gets deposited on teeth
-<8 yrs age
Do not mix injectable tetracycline with …..
Penicillin - inactivation occurs
Tetracyclines should not be given along with ……drug
Should not be given …..
Diuretics
Intrathecally
Chronic tetracycline use can cause …..(2)
What is Fanconi’s syndrome?
Esophageal and vaginal candidiasis
Tetracycline beyond expiry date
Tigecycline is a ……analogue. Use
Minocycline
It is 20 times more potent than tetracyclines
Tigecycline is given for …..(3)
It is eliminated through …..
MRSA
VRE
Complicated skin and soft tissue and intra abdominal infections
Bile
Chloramphenicol is obtained through …..
It is a ……ring moeity. It is bacterio….
Streptomyces venzuelae
Nitrobenzene ring moeity
Bacteriostatic
MOA of chloramphenicol
At higher doses it inhibits …..
Inhibit peptide bond formation from P window to A window
Mamalian mitochondrial protein synthesis as well. Bone marrow cells are susceptible
Adverse effects of chloramphenicol
BIG Super Hypersensitivity
Bone marrow suppression
Irritable sms: n/v if ingested, pain on iv
Gray baby syndrome
Superinfections
Hypersensitivity reaction
What is gray baby syndrome?
Premature infants lack liver UDP- glucoronyl transferase characterized by :
Cyanosis
Abdominal distension
Hypothermia
CVS collapse
Death
Chloramphenicol is a potent enzyme inhibitor and inhibits …..(3)
Morphine ( respiratory depression)
Chlorpropamide (hypoglycemia)
Warfarin ( bleeding)
Daily dosing of chloramphenicol
What should be kept in mind?
Should not exceed 2-3g daily. Rx course <2 weeks should not exceed <28 gram.
Daily CBC should be done and if seen anemia /TCP, drug should be stopped.
Uses of chloramphenicol
BARE TB
Bacterial meningitis/ pyogenic meningitis
Anerobic infection
Rickettsia
Ear and eye infection( conjunctivitis & endopthalmitis)
Typhoid
Brucellosis
Bacterial cell wall structure consist of ….
- N-acetyl muramic acid (NAM)
- N-acetyl glucosamine (NAG)
Only NAM consists of peptidoglycan residues to it, and cleavage of last chain of NAM releases energy that helps transpeptidase in crosslinking NAM forming stability to bacterial cell wall
Beta lactams are more susceptible to ……bacteria. Why?
Gram +ve bacteria- as they have more peptidoglycan to it.
Resistance of beta lactams
- Altered permiability: decrease influx, increase efflux
- Formation of betalactamases/penicillinase
- Alteration of penicillin binding protein (pbp) so that betalactams can’t destroy the transpeptidases.
MRSA is by this mechanism
Uses of penicillin G
LAST MAN DP
leptospirosis
Actinomycetes
Staph,strept
Treponema, tetanus
Meningococcus
ANthrax
Diphtheria
Pneumococcus
What are the extended spectrum penicillin?
A CT MAP
Amino gp: Amoxicillin, ampicillin
Carboxy gp: carbenicillin, ticarcillin
Ureido gp: Mezlocillin,Azlocillin,Piperacillin
Ureido group has the broadest spectrum
Why are beta lactam antibiotics called so?
What are the egs?
Coz they have beta lactam rings next to thiazolidine ring
They are:
Penicillin
Cephalosporin
Carbapenems
Monobactams
Who discovered penicillin?
Penicillin is obtained from….
Alexander Flemming
Fungus: penicillinium notatum, penicillium chrysogenum
MOA of beta lactams
Bind to penicillin binding protein and block transpeptidase. Cell wall becomes unstable—> cell wall deficient bacteria, water gets in osmotically, bacteria swell and lysis.
Thus all beta lactams are bactericidal
Natural penicillin was ……
3 problems with it
Penicillin G - benzyl penicillin
3 problems:
1. Acid labile
2. Penicillinase suseptible
3. Narrow spectrum- only gram +ve.
Which is the acid resistant penicillin ?
Phenoxymethyl penicillin- penicillin V
Depot IM formulation of penicillin G (2)
- Procaine penicillin G
- Benzathine penicillin G
Penicillin G is excreted by …..
Prophylactic uses of penicillin G (3)
Kidneys
- Rheumatic fever
- Bacterial endocarditis
- Agranulocytosis
DOC for treponema pallidum
What are the penicillinase resistant penicillin?
Benzathine penicillin
CONDoM
Cloxacillin
Oxacillin
Nafcillin
Methicillin
Methicillin causes …..s/e
Interstitial nephritis
Amoxicillin is better than ampicillin by :
(3)
- Oral bioavailability- doesn’t interfere with food absorption
- Incidence of diarrhoea is lower
- Preferred over ampicillin for bronchitis,
UTI,
SABE,
Gonorrhoea
The disadvantage: it is less effective than ampicillin for shigella and H influenza.
Adverse effects of penicillin G (3)
- Local reaction
- Hypersensitivity reaction
- Jarisch Heixermer reaction
Antipseudomonal penicillin are
CT MAP
Carbenicillin
Ticarcillin
Mezlocillin
Azlocillin
Piperacillin
What are the beta lactamase inhibitors?
What are they?
They are suicide drugs, given along with penicillin to prevent its degradation by betalactamases.
They inhibit beta lactamases first , so that beta lactams can now perform their action.
They are:
Clavulonic acid - with amoxicillin
Sulbactam with ampicillin
Tazobactam with piperacillin
They are combined like this as combinations are due to similar t1/2.
Extended spectrum penicillinase inhibit all except ….
Beta lactam that resemble aminoglycosides s
Carbapenems
Monobactams
Use of Monobactams (3)
- Only gram -ve orgs, no effect on gram +ve.
- Can be used for penicillin/cephalosporin allergy -esp ceftazidime allergy
- For those with renal insufficiency who can’t use aminoglycosides
Carbapenems are DOC for …..
Imipenem is always given with …..
Enterobacteria
Cilastatin-as imipenem is degraded by renal dihydropeptidase 1. Vikas Yatin is inhibitor of this enzyme.
S/e of carbapenems
Seizures at high levels - imipenem only.
Others are stable to renal dihydropeptidase, and do not cause seizures
Main side effect reactions with
Methicillin:
Oxacillin
Cross reactivity of penicillin and cephalosporin is ….% of patients
Interstitial nephritis
Hepatitis
6-10%
MOA of vancomycin
It is bacteri….
Inhibit mucopeptide cell wall formation by binding to D-ala D ala portion of cell wall precursors
Bactericidal
Resistance of vancomycin
D-ala d-ala is changed to d-ala d-lac
vancomycin is DOC for (2)
- MRSA
- Clostridium difficult
Gram +ve aerobic bacteria
S/e of vancomycin (4)
Nephro toxicity
Ototoxicity
Thrombophlebitis
Diffuse red man syndrome - diffuse flushing
Rx: prerx of antihistamine, slow infusion rate.
Drug more active against enterococci than vancomycin is ….
Use of teicoplanin (2)
S/e of teicoplanin
Teicoplanin
Endocarditis prophylaxis
Pseudomembranous colitis
Bronchi spasm-rarely
Those betalactams that interfere with coagulation test (3)
Telavancin
Dalbevancin
Ortivancin
Daptomycin is inactivated by …..
S/e of daptomycin (2)
Pulmonary surfactant
Myopathy
Eosinophilic pneumonia
Bacitracin is mainly …..
Active against (3)
Topical
Staph,strept,clostridium difficle
Use of fosfomycin
Use of cycloserine
Single 3gm to rx uncomplicated UTI in women
Safe in pregnancy
Used as second line drug in TB
Cephalosporin are beta lactamase…..
Resistant , except first gen
Broader spectrum of activity
Cephalosporin active against MRSA
5th generation
How to remember cephalosporin generation?
Cef “a” — first gen except : cefaclor
Cef (pi)—- 4th generation
Cef (me,one,ten)—-3rd generation , moxilactam cefuroxime: 2nd generation
Cef (rol) ——5th generation
Rest all are second gen.
Cephalosporins have ……group
Methylthiotetrazole
Cephalosporin can cause _______s/e (2)
Hypoprothrombinemia
Disulfiram like reaction
S/e of ceftriaxone
Cholelithiasis
Cephalosporin used for
1. Gonorrhoea
2. Typhoid
3. Surgical prophylaxis
- Ceftriazone
- Ceftriazone
Cefoperazone - First generation
Moa of echinocandins
Egs
Inhibit 1-3 beta glycan- a component of fungal cell wall.
Caspofungin
Micofungin
Echinocandins can be used for …..fever
Neutropenic fever not responding to antibiotics
Echinocandin that requires
Loading dose
That which do not require loading dose
Loading dose: caspofungin
No loading dose: micafungin
Ciclopirox MOA use.
Moa: inhibit DNA rna synthesis
Use : shampoo for seborrheic dermatitis
MOA of polyene group
Ampho B and nystatin
Creates pores in bacterial cell membranes and increase in efflux of membrane ion
Thus causing fungicidal action
How is amphoB given in iv?
How is amphoB given in rx?
Dilute with 5% glucose/ dextrose
Saline makes it very coarse
Ampho B + flucytosine = synergistic action.
Adverse effects of ampho B (2)
- Mc infusion reaction : hypotension, fever, chills.( shake and bake syndrome)
- Nephrotoxicity: type 1 RTA: decrease K+, mg2+.
Thus ampho B is given as liposomal ampho b
Source of amphoB
Source of nystatin
Streptomycetes Nodosum
Streptomycetes noceri
MOA of Azoles
Inhibit new protein synthesis by inhibiting dimethylase .
(Lanosterol —x——> ergosterol
They are fungistatic
S/e of imidazoles
Only oral azoles
Enzyme inhibitor
Adrenal suppression
Ketoconazole
Itraconazole
Antifungal with longest t1/2, shortest t1/2
Longest: isavuconazole
Shortest: voriconazole
Antifungal with both anti I.f and antipruritic action
Itraconazole is DOC for …(3)
Sertaconazole
Histioplasmosis
Sporotrichosis
Blastomycosis
Antifungal effective on both dermatophytes and systemic
DOC for dermatophytes
Ketoconazole
Terbinafine
Protein synthesis inhibitor of anti fungal
Inhibits dna and rna synthesis
Tavaborole
Flucytosine, ciclopirox
Flucytosine useful for …..(2)
Candida
Cryptococcal
S/e of flucytisine
Antifungals with renal elimination
BMS, hepatotoxic
Fluconazole
Flucytosine
Voriconazole given for ….
Azole with no CNS penetration
Aspergillosis
Itraconazole
S/e of griseofulvin
Important feature of griseofulvin
Disulfiram reaction
Can be taken with fatty meals
S/e of voriconazole
Micafungin increase levels of ….(2)
Visual disturbances
Nifedipine
Cyclosporin
Azole used for mucormycosis
Drug used as shampoo (2)
Posaconazole
Ketoconazole
Ciclopirox
Ampho B is active against all except ..(2)
- Paracoccidiomycosis
- Chromomycosis
Terbinafine is given …..
Butenafine is given ….
Both topical and oral
Topical
Anti fungal to be avoided in ventricular dysfunction
Antifungal with widespread resistance
Use to rx……
Itraconazole
Griseofulvin
Only dermatophytes
MOA of terbinafine
Doc for onychomycosis
Inhibit squalene epoxide, squalene increases, fungicidal action.
Terbinafine
Finger nail: 6weeks
Toe nail: 12 weeks
Drug with relatively drug drug interaction
Micafungin
Hyphal distortion is by …..
Tolnaftate
MOA of human influenza virus
Human influenza virus has hemagluttinin and neuraminidase proteins on it, along with M2protein ion channels.
1. Uncoating:
Influenza binds to sialic acid on the host cell with HA and is pushed into the cell.
In the cell, matrix protein opens the ion channels and viral mrna is pushed out.
- Endonuclease:
Viral mRNA goes to nucleus and the endonuclease enzyme takes host 5’ cap of host mrna and fixes it on viral mrna.
Viral mrna goes to ribosomes and forms structural and functional proteins.
These proteins goes to Golgi apparatus; gets packaged into vesicles and ready for exocytosis.
- Exocytosis
When the vesicle reaches the cell membrane, it fuses with the cell membrane, and is still stuck to the sialic acid of the host cell with HA of virus.
Neuraminidase of this virus comes and cleaves the HA-sialic acid bond and virus buds off and released.
Antiinfluenza Drugs that inhibit M2 ion channels
Uncoating inhibitors: Amantadine
Rimantadine
Which influenza does it uncoating inhibitors cover?
What are the adverse effects? (3)
Only influenza A
Ataxia
Livedo reticularis
Prolonged Qt interval—>TdP
What are the drugs that inhibit endonuclease?
Which influenza does it cover? Importance ?
Baloxavir
Covers both influenza A&B
If given <48 hrs of sm onset.
What antiinfluenza inhibit neuraminidase enzyme? Importance
Oseltamivir
Zanamivir
Works only when given less than 48 hrs of symptom onset and prophylaxis in adults and children > 5yrs.
MOA of HBV
HbV is a partially ds DNA, binds to NCTP protein of human cell and gets into the cell.
Partially dsDNA is taken into the nucleus and forms complete ds DNA and can replicate consistently.
Some of the dna gets converted via transcription to
1. mrna and goes to ribosomes to make proteins that goes to Golgi apparatus.
2. Pregenomic mrna
Reverse transcriptase converts pregenomic rna to dna and together with structural proteins in Golgi apparatus, gets packaged into vesicles and exocytosed.
AntiHBV drugs that inhibit reverse transcriptase?
NRTI: lamivudine, entecavir
NtRTI: adefovir, tenofovir
Which of the antiHBV drugs is responsible for fanconi syndrome ?
Which drug inhibit protein that forms MHC class 1 molecule?
Adefovir, tenofovir
Interferon alpha
Adverse effects of INF alpha (2).
Teratogenic
Pancytopenia
MOA of HCV
Virus gets into the human cell—> rna goes to RER—> forms big polyproteins:
NS3-NS4A-NS5A-NS5B
Enzyme NS3/4A protease cleaves these polyprotein into structural and functional proteins —> Golgi apparatus —> packaged into vesicles and exocytosed.
AntiHCV drugs that inhibit NS3/4A protease?
Protease inhibitors -previr
Drugs that inhibit NS5A protein
Drugs that inhibit NS5B protein
-asvir: daclatasvir, ledipasvir
-buvir: sofosbuvir,dasabuvir
Which antiHCV drugs inhibit inosine 5PDH preventing guanosine nucleotide thereby preventing RNA formation?
Indication and s/e of above
Ribavirin
Indication:
Refractory HCV, as triple therapy:
Ribavirin+INF+ sofosbuvir
S/e: teratogenic, hemolytic anemia
MOA of herpes
Viral DNA gets into the cell—> dna polymerase —> replication.
Some dna goes to nucleus, gets converted to RNA—> ribosomes—> proteins—Golgi apparatus —> exocytosis
Drugs which inhibit DNA polymerase in herpes rx?
Which one is pyrophosphate analogye?
Cidofovir, foscarnet
Foscarnet
Indication of DNA polymerase inhibitors of herpes rx?
Ganciclovir resistant CMV
Aciclovir resistant HSV
Which DNA polymerase inhibitor causes seizures?
Which one causes crystal Nephropathy? What should be done?
Foscarnet
Cidofovir
Give along with IV fluids and probenecid
Which anti herpetic drug is posphorylated ibto guanosine analogue?
Indications (3)
Aciclovir, valaciclovir
HSV esophagitis, meningitis, mucocutaneous lesions.
Which guanosine analogue in herpes rx causes Nephropathy?
Which one causes TTP?
Aciclovir-give with IVF.
Aciclovir,valaciclovir
Adverse effect of ganciclovir
Indications
A/e: BMS
Indication:
CMV: esophagitis, retinitis,
Pulmonary nodular amyloidosis
RNA polymerase inhibitor for RSV is..
Fusion inhibitor is ….
Ribavirin
Pavlizumab
Drug against Envelope proteins for HSV
Docosanol
Terminase inhibitor of CMV
Letermovir
Rx of human small pox. Viral target
Target: VP37 envelope wrapping protein
Drug: tecovirimat
MOA of NRTI and NNRTI
Both block reverse transcriptase preventing conversion of viral RNA to DNA .
NRTI: conpetitive inhibitor-binds to active site
NNRTI: non competitive inhibitor-binds to allosteric site and cause conformational change of the reverse transcriptase enzyme.
Egs of NRTI and NNRTI
NRTI: ZALES TD
Zidovudine
Abacavir
Lamivudine
Stavudine
Tenofovir
Didanosine
NNRTI:
-vir-
Nevirapine
Efavirenz
MOA of protease inhibitors egs
Inhibit the cleaving of viral polyprotein.
Those that end with -navir
MOA of entry inhibitors eg. (4)
- Blocks gp 41 to bind to CD4T cell- enfuvirtide
- Blocks CCR5 receptor : Maraviroc
- Blocks CD4 receptor: Ibalizumab
- Blocks binding of Gp120 to CD4: Fostemsavir
What are the integrase inhibitors ? Eg
Blocks the integration of viral DNA into host DNA.
Those that end with -gravir.
Integrase inhibitors are also called ……
Strand transfer inhibitors
Combined side effect of NRTI and NNRTI
NRTI: mitochondrial injury-
Myopathy
Peripheral neuropathy
Hepatic steatosis
Lactic acidosis
NNRTI: Rash
NRTI also effective against Hep B are :
(3)
Tenofovir
Emcitrabine
Lamivudine
Safest NRTI
Lamivudine
Emcitrabine
Lamivudine is a …..analog
Emtricitabine is a …….analog
Deoxycytidine analog
Fluorinated cytidine analog
Abacavir is a …..analog
S/e
Guanosine analog
Hypersensitivity especially in HLAB5701 pts. This is called pharmacogenetics
Only nucleotide in NRTI is ……s/e…(2)
Tenofovir
S/e: renal toxicity
Osteoporosis
Tenofovir not suitable for lactose intolerant patients why?
Coz tenofovir is formulated with lactose.
Toxicity of zidovudine
Other side effects (5)
Bone marrow suppression
Insomnia
Myopathy
Hyperpigmentation of skin and nails
Lactic acidosis
Hepatomegaly
S/e of didanosine
S/e of stavudine (3)
Pancreatitis
Peripheral neuropathy
Lactic acidosis
Highest risk for lipodystrophy
Toxicity of zalcitabine
Toxicity of nevirapine
Oral ulcer
Hepatotoxicity
S/e of efavirenz
One thing to note is …..
Neuropsychiatric symptoms: vivid dreams
Qt prolongation —>Tdp
Avoid taking it with fatty meals
Etavirine is given as …
Another drug given same is ….
Combination drug
Emcitrabine -also given as combination drug
Side effect of protease inhibitors (4)
Metabolic abnormalities: (4)
Dyslipidemia
Hyperglycaemia
Insulin resistance
Lipodystrophy
All Protease inhibitors are potent ….
CYP3A4 inhibitors -increase risk of bleeding in hemophiliacs
Protease inhibitor with least dyslipidemia
S/e (2)
Atazanavir
Hyperbilirubinemia
Nephrolithiasis
The rationale for giving lopinavir + Ritonavir is ….
Ritonavir is a potent CYP 3A4 inhibitor. In low dose , it boosts all other protease inhibitors.
Side effect of indinavir (2)
Indirect hyperbilirubinemia
Nephrolithiasis
Nelfinavir has ….s/e
……is used with nelfinavir
Hepatotoxic
Sweetner aspartame is used with nelfinavir as it contains phenylalanine
Least potent CYP3A4 inhibitor:
Prodrug of amprenavir
Saquinavir
Fosamprenavir
S/e of raltegravir (2)
S/e of dolutegravir (2)
Myopathy
Rhabdomyolysis
Insomnia
Headache
Why is carbotegravir always used with rilpivirine?
As it causes depression and hepatic dysfunction
Indication for use of cobicistat
Pharmacokinetic enhancer
Used in combination with darunavir/atazanavir
Increases the effectiveness of the HIV meds.
MOA of pyrantel palmoate
Direct depolarization blocker.
Binds to Nm receptor( where Ach normally binds); causes parasitic muscle contraction, but too much pyrantel palmoate desensitizes the Nm receptor—> muscle relaxation—>fecal excretion
Therefore pyrantel palmoate causes spastic paralysis in parasite
MOA of piperazine
GABA agonist
Opens chloride channels->chloride comes into the parasite cell->hyperpolarization->muscle relaxation->fecal excretion.
Thus piperazine causes flaccid paralysis in worms
MOA of ivermectin
Opens glutamate gated chloride channels->chloride gets in—>hyperpolarization—>muscle relaxation—>fecal excretion
MOA of DEC - diethylcarbamazepine
Changes Arachnidonic acid metabolites in the worms, immune system recognises this and phagocytosis by monocytes.
MOA of niclosamide
Inhibit glucose uptake—>no oxidative phosphorylation—>no energy —>worm die
MOA of praziquantel
Destroys voltage gated calcium channel—>calcium gets inside the worm cell unregulated—>excess calcium —>rapid contraction—>paralysis
MOA of mebendazole
Binds to beta tubulin —> inhibits polymerization—>inhibits mitotic spindle —>inhibits cell division —>cell death.
MOA of metrifonate
Organophosphorus
Similar action of pyrantel palmoate-direct depolarization blocker.
MOA of oxamniquine
MOA of bithionol
Blocks DNA synthesis in parasite
Blocks ATP synthesis in parasite
Drugs causing uncoupling of oxidative phosphorylation (2)
Bithinol
Niclosamide
DOC for trematodes
Egs (2)
Praziquantel
Blood fluke-schistosoma hematobium
Lung fluke-paragonimus westermani
DOC for liver fluke is ….
(Fasciola hepatica)
Triclabendazole >bithinol
DOC for cestodes is …..except…
Praziquantel
Except:
1. Neurocysticercosis: tenia solium(pork)
2. Hydatid disease ( echinococcus granulosus-dog tapeworm)
—DOC : albendazole
DOC for nematodes except: (4)
Albendazole
1. Pinworm: mebendazole
2. Threadworm: ivermectin
3. Filariasis (wucheria bancrofti): DEC
4. Onchocerca volvulus: ivermectin
DOC for guinea worm: dracunculosis
Metronidazole , niridazole
Albendazole is DOC for (5)
- Cutaneous larva migrans
- Visceral larva migrans
- Toxocariasis
- Hydatid disease: 6months Rx
- Neurocysticercosis: 1 month Rx
Drug given for neurocysticercosis
Albendazole + praziquantel
Praziquantel is c/i in ……
Ocular cysticercosis
Rx regimen for filariasis
Adverse effect (2)
Albendazole + DEC/ivermectin
Liver toxicity
Bone marrow toxicity
Important thing about benzimidazoles
C/I in first trimester
Can be given in second /third trimester
Uses of ivermectin (5)
- Onchocerciasis
- Lymphatic filariasis
- Scabies
- Head lice
- Strongyloides
Antibiotic useful in filariasis
Antihelminth with immunomodulatory action
Doxycycline
Levimazole
Drug with anti protozoal,antiviral,antihelminth activity
Nitazoxanide
MOA of amebiasis
Cysts in the lumen (quadrinucleate) forms tennis racquet shaped structure-trophozoites—> cyst and is excreted.
- Patient can be an asymptomatic carrier
- Trophozoites can invade the intestinal lumen and cause amebic colitis
- Trophozoites can via blood go to liver and other organs and infect them -extraintestinal amebiasis
Antiamebic drugs classification
- Patients with asm carrier :
Rx with luminal agents -cysts in intestine are killed- diloxanide furoate
Others : paramomycin, iodoquinol - Amebic colitis + extraintestinal amebiasis:
Start by killing Trophozoites:
a. Metronidazole
b. Emetine
c. Chloroquine
Then Rx with luminal agents to kill the remaining cysts.
S/e of emetine
Importance of chloroquine
Highly cardiotoxic
Kill liver amebiasis, not intestinal ones.
MOA of metronidazole
It’s is a nitro group that releases free radicals upon oxidation and damage the parasites
They are cidal drugs
S/e of metronidazole (3)
- Metallic taste -anorexia
- Pancreatitis -rare.
- Disulfiram like reaction- due to accumulation of aldehyde dehydrogenase
Drugs causing disulfiram like reaction
C: chlorpropamide, cefoperazone
G: griseofulvin
M: metronidazole
P: Procarbazine
Uses of metronidazole (3)
A. Anti protozoal :
1. Amebiasis -amebic colitis and extraintestinal
2. Trichomonas vaginalis
3. Giardiasis
B. Antibacterial
1. Anerobic bacteria
Bacteroids fragilis
Pseudomembranous colitis
Acute necrotizing gingivitis-trench mouth.
- H.pylori- quadruple regimen
- Bacterial vaginosis
C. Antihelminth:
Guinea worm- dracunulosis
Advantages of tinidazole over metronidazole
Tinidazole- decrease metallic taste
Better safety profile
Longer t1/2 than metronidazole
Longest nitroimidazole drug
Secnidazole
Classification of antimalarials based on : (4)
- Preerythrocytic phase. Prophylaxis
- Exoerythrocytic phase: radical cure
- Erythrocytic phase: clinical cure
- Gametocytic phase: prevent human-mosquito transmission.
Infective form of parasite is ….
Sporozoite -present in the saliva of female anopheles mosquito.
Definitive and intermediate host of malaria
Definitive: female anopheles mosquito
Intermediate: man
Life cycle of plasmodium
Bite of mosquito —> sporozoites present in the saliva of mosquito gets into the human cell—>
1. Liver : preerythrocytic phase
Sporozoites—>merozoites
Exoerythrocytic phase:
Sporozoites—> hypnozoites
2. Blood:
Merozoites rupture the liver cells and gets into the blood.Erythrocytic phase.
Fever happens when the blood cells rupture ie, every 2nd-3rd day.
Merozoites can get converted to Trophozoites, schizonts and more merozoites.
Merozoites then can form gametocytes.
- Mosquito bite the infected person, the gametocytes goes to the intestine of the mosquito, fertilize and the zygote gets converted into sporozoites which gets to the saliva of the mosquito.
Rx for chloroquine sensitive P, falciparum
Chloroquine + primaquine
( although p falciparum doesn’t have an Exoerythrocytic phase, primaquine is given for the gametocidal action.
Rx for chloroquine resistant p falciparum
Artesunate + mefloquine
Artemether+ lemefantrine
Artesunate + sulfadioxime + pyrimethamine
Rx for Chloroquine sensitive p.vivax
Chloroquine + primaquine
Chloroquine resistant P.vivax (3)
- Artesunate + primaquine
- Quinine+ doxycycline
- Clinadamycin + primaquine
Falciparum malaria is mainly seen in …….area
Rx for uncomplicated p.falciparum in pregnancy
North eastern states
1st trimester: quinine salt
2nd/3rd: area specific ACT
DOC for p.vivax in pregnancy
Chloroquine
Full form of NVBDCP
National vector borne disease control program
MOA of chloroquine
Chloroquine gets taken up by infected RBC —> increased Ph in vesicle
Hb—>heme—>hemazoin
Inhibited by Cq
Heme increases—->toxic to the parasite.
Rupture of plasmodium membrane but not RBC.
Drugs with MOA similar to chloroquine (3)
Quinine
Mefloquine
Lumefontrine
Uses of chloroquine
REDLIP Mahatma Gandhi
Rheumatoid arthritis
Extraintestinal amoebiasis
DLE
Lepra reaction
Infectious mononucleosis
Photogenic reaction
Malaria
Giardiasis
Chloroquine has a high Vd (100L/kg)
Adverse effects of chloroquine
ROOP Depress my Heart
Rash
Ototoxic
Oculotoxic
Peripheral neuropathy
Depress-myocardial depression
H-hypotension
Drugs acting on Erythrocytic phase
Fast acting:
Mefloquine
Atorvaquine
Chloroquine
Halofantrine
Artemisin
ResQ (quinine)
Slow acting :
Proguanil
Tetracycline
Uses of mefloquine (2)
Cq sensitive and resistant P falciparum
Cq resistant p vivax
S/e of mefloquine
Sinus bradycardia
Neuropsychiatric sms: fuzzy thinking,nightmares
Oldest antimalarial is …..obtained from….
Quinine
Bark of the Cinchona tree
Define Cincchonism (5)
- Tinnitus
- High frequency hearing loss
- N/V
- Dysphoria
- Postural hypotension
What are the other side effects of quinine (2)
Qt prolongation
Hypoglycemia-infuse with 5% dextrose
How is pyrimethamine given? MOA?
MOA: DHFR inhibitor:
inhibits DHFA—->THFA
Infuse with 5% dextrose to prevent hypoglycemia
Given along with sulfonamide
S/e of primaquine
C/I of primaquine
- N/V -prevented by taking with high fatty meals .
- megaloblastic anemia at high doses.
C/I : Hemolytic anemia in G6PD patients
Pregnancy
MOA of primaquine
Contains reactive metabolite which desrupt ETC of parasite.
Hemolytic anemia is seen in ….places (4)
Jharkand
Madhya Pradesh
Andra Pradesh
Assam
Antimalarial given as single dose
Use.
Tafenoquine
Radical cure
S/e of artemesin (2)
Reticulocytopenia
Neutropenia
Artemesin obtained from ….
Artemesia-Chinese plant
Water soluble artemesin
Lipid soluble artemesin
Water soluble: Artesunate
Lipid soluble: artemether
Artemesin developed in india for IM use
Artemesin developed in india for oral use
Arteether
Arterolane