abtics by dr san
Post on 03-Jun-2015
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Dr STSA
Antibiotics - chemical substances originally produced
by various species of micro-organisms (bacteria, fungi,
actinomycetes) that in high dilution suppress the
growth or cause death of other microorganisms
Objective of Rx- For curative - eradication by lethal
effect,inhibit growth & multiplication,phagocytosis
For preventive
Antimicrobial agents 3
Bacteria
Bacteriostatic• inhibiting the growth or multiplication of bacteria
Bactericidal• lethal effect on mature bacteria /kill the bacteria
Antibacterial spectrum
• list of bacteria which are normally susceptible to
antibacterial action of a particular agent (group or
particular organisms)
Antimicrobial agents 5
Antimicrobial agents 6
Antimicrobial agents 7
C
Classification based on their Mechanism of Actions
1. Drugs that inhibit the synthesis of bacterial cell walls
eg.Penicillins, Cephalosporins, Vancomycin Clotrimazole
2. Agents that act directly on the cell membrane eg‘.Nystatin, Amphotericin
Antimicrobial agents 8
Cont-
3. Drugs inhibiting microbial protein synthesis by their effect on bacterial ribosomes
(A) disrupt the function of 30S or 50S ribosomal subunits to reversibly inhibit
protein synthesis (mainly bacteriostatic)
eg – Chloramphenicol, Tetracyclines, Macrolides,
Clindamycin, Lincomycins
(B) agents that bind irreversibly to 30s ribosomal subunit (mainly
bactericidal)
– Aminoglycosides eg. GentamicinAntimicrobial agents 9
4. Drugs that affect nucleic acid metabolism
eg.Rifampicin,Fluoroquinolones,Griseofulvin Metronidazole
5. The antimetabolites - Drugs affecting the intermediary metabolism which are essential to micro-organisms Sulfonamides Competitive
antagonist of Para-aminosalicylic acid PABA
(PAS) Trimethoprim
inhibit DHFA-reductase enzyme Pyrimethamine
• MOA
-inhibit the bact:cell wall syn by binding to protein,inhibit crosslinking enz ∆ autolysis
Classification of Penicillins
1. Penicillin G - Benzyl penicillins
(a) Penicillin G- Crystalline I.V (Aqueous Pen G as K+ salt and Na+ salt) (2,50000 to 10,00000 units IM, IV)
(b) Penicillin G -Procaine suspension (3,00000 to 6,00000 units IM)
(c) Penicillin G -Benzathine suspension (0.6 to 1.2 mega units IM)
2. Penicillins V (oral) Phenoxymethyl penicillin(250-500mg)
3. Penicillinase-resistant penicillins (Anti-staph) Cloxacillin – orally,IM, IV
Flucloxacillin
Dicloxacillin, Oxacillin
Antimicrobial agents 12
• Methicillin - use as a laboratory tool for identification of
methicillin - resistant - Staphylococcus aureus (MRSA)
(MRSA = resistance to all the penicillinase-resistant penicillins and
cephalosporins) (Vancomycin is a drug of choice in MRSA)
4. Broad spectrum penicillins
Ampicillin
Amoxicillin
5. Antipseudomonal penicillins
Carboxypenicillins - Carbenicillin Indanyl (oral), Ticarcillin
Ureidopenicillins - Piperacillin
6. Penicillin β-lactamase inhibitor combination
Co-amoxiclav (Amoxicillin + clavulanic acid)
Pen GOrganisms Usage Dosage/Route
gram(+)ve cocci (except penicillanase producing )staph -pneumococci -Streptococci
gram (-) cocci - meningococci, gonococci
Infections caused by-non-β-lactamase-producing staphylococci, -pneumococci-Streptococcal pneumo:
-Prophylatic Tx:*
- meningococci, gonococci
Crystalline- IV 30 mg/kg6H (1mg=1667u)Severe inf:50 mg/kg 6H (max 2G)12 H/6HProcaine-IM 25-50 mg/kg 12H/OD(Max 1.2-2.4G)Benzathine –IM25mg/kg OD,3-4wkly
non-β-lactamase-producing anaerobes
non-β-lactamase-producing anaerobes
Organisms Usage Dosage/Route
gram (+) bacilli – C. diphtheriae, B. anthracis, Clostridium, Actinomyces
DiphtheriaInfection due toBacillus anthracisClostridium species-Actinomyces* and other gram-positive rods
C/pen 30-50mg/kg 6H
spirochetes Treponema pallidum (syphilis) and many other spirochetesProphylatic Tx
C/pen “
Pen V
•gram (+)ve cocci (except penicillinase producing staphylococci)* narrow antibacterial spectrum
o minor infections (streptococcal pha-ryngitis)
o prophylaxis of streptococcal infection following rheumatic fever and pneumococcal infection (following splenectomy) fusospirochetel infection (gingivostomatitis)
oral 15 mg/kg 6H (125-250mg) 12.5 mg/kg 12 H
Organisms Usage Dosage/Route
Pen resistent pen
Org Usage Dosage
more effective against penicillinase producing - staphylococci
staphylococcal infections-skin,LRIT
Cloxacillin – orally,IM, IV15 mg/kg 6H25- 50mg/kg 12H,4-6H, Flucloxacillin12.5-25 mg/kg 6H25-50 mg/kg 8H,6H
less effective than pen. G and pen. V against Gram positive bacteria
Some strains of Gram negative bacteria
H. influenzae, E. coli,gonococci, Klebsiella
Aminopenicillins (Ampicillin, Amoxicillin)Org Usage Dosage
gram (-)ve, (+)ve bacteria(H. influenza, E.coli and Proteus mirabilis)
URTI (sinusitis, otitis media, acute exacerbations of chronic bronchitis & epiglottitis) Lower RTI, UTI, Biliary tract Meningitis,
Salmonella infection (Enteric fever) H. pylori
Oral/I.M/I.V 10-25 mg/kg 6H /8H severe -50mg/kg
‴Listeria monocytogen
sensitive against β-lactamase producingstrains of G (+)ve & G (–)vebacteria*.Staph,Gono,H. influenzae, E coli, Klebsiella, Proteus, Bacteroides fragalis, Moraxella catarrhalis
Penicillin - β-lactamase inhibitor combination (Clavulanic acid or Sulbactam)20-25 mg/kg IM,IV 6H
Antimicrobial agents 19
Vancomycin
Antimicrobial agents 20
Red man syndrome
Mechanism of Action• similar to penicillin , bactericidal, inhibit bacterial cell wall synthesis Classification of Cephalosporins I. The first generation cephalosporins Cefalexin Cefadroxil Cefazolin II. The secondgeneration cephalosporins Cefuroxime axetil ,Cefaclor (Oral) Cefuroxime Cefoxitin IV,IM• Cefotetan
III. Third generation Cefixime(oral)
Cefotaxime
Ceftriaxone IV,IM
Ceftazidime
IV. Fourth generation
Cefepime (I.V)
The First Gen:CephaloDrug Theraputic advantage Dosage
Gram- positive cocci (except MRSA)
upper and lower RTI Cefalexin- 7.5mg/kg 6h Cefadroxil 15-25mg/kg 12h Cefazolin
Gram-negative bacteriaEcoli,Kleb,ProteusOral cavity anaerobic cocci
urinary tract infection surgical prophylaxis
some β lactamase producing strains (e.g, Staphylococcus)
skin and soft tissue infections owing to S. aureus and S. pyogens
The second gen:cephaloGram + ve RTI (oral) Cefuroxime axetil 10-
15 mg/kg bdCefaclor 15mg/kg 8h
anaerobes (Bacteroids fragilis)
anaerobic infection -pelvic inflammatory disease,-Intra-abdominal inf,- diabetic foot
Cefuroxime iv25-50 mg/kg 8,12,6 hr
Gram-ve bacteria(< 3rdG) (Neisseria,H.influenzae, Enterobacter Proteus, E.coli, Klebsiella)
G (-)ve bacterial
The third gen:cephaloless active against G + ve DOC for serious
infn (Septicaemia,Pneumonia,Meningitis)
Cefotaxime iv25-50mg/kg-12 h 8 h/6 hCeftriaxone -iv,im25-50mg/kg 12h,8h
more active against G -ve
Oral-Cefixime 5mg/kg od Cefpodoxime ″ bd
much more active enterobacteriaceae &β-lactamase producing strainss/a (H. influenzae & Neisseria)
some - active against P.aerug Ceftaxidime iv,im15-25mg/kg 8h
Enteric feverSevere Lyme’s d/sGonococcal
The forth generation
• Cefepime (I.M ,IV)
25-50 mg/kg 12h
Antimicrobial agents 27
Untoward Effects
1.Hypersensitivity is most common
cross hypersensitivity & resistant < 10%
Caution – Penicillin allergic patient
2. Nephrotoxicity - ↑ with aminoglcosides
3. Renal tubular necrosis (Cephaloridine, Cephalothin)
4. Intolerance to alcohol (disulfiram –like reaction)
28Antimicrobial agents
MACROLIDEAntibacterial Activity Therapeutic Uses Dosage
G +ve (same as Pen G) alternative to penicillins in strep pharyngitis, staph infections, tetanus, syphilis,Bacterial endocarditis ,Rheumatic feverDiphtheria, Pertussis,
ErythromycinOral 10-15mg/kg 6h 25 mg/kg 6h
Chlamydia trachomatis,Mycoplasma, Legionella,
luminal amoebicide
Chlamydial infections, Mycoplasma p’nia,Legionnaires’ diseaseCampylobacter infections Intestinal amoebiasis
Mycobacterium Mycobacterial infection Azithromycin 15mg/kg D17.5mg/kg D2-5
more potent than erythromycinstrept, staph,ChlamydiaMycoplsma and H.pylori
Eradication of H.pylori in peptic ulcer
Chlarithromycin
Untoward Effects- not common• cholestatic hepatitis is common with erythromycin
estolate (esp. in pregnancy)• allergy, GI disturbances, arrhythmia*• reversible hearing lossContraindication• liver disease, pregnancy
Drug Interaction
Erythromycin and clarithromycin inhibit CYP3A4
potentiate the effects of digoxin, theophylline & valproate
LINCOSAMINES (Lincomycin and Clindamycin)
Antibacterial Activity Therapeutic Uses Dosage
Anaerobic bacteria (Bacteroides species, Clostridium)
peritonitis, pelvic inflammation
Lincomycin 10mg/kg 8h oralIM or IV (over 1h)10 -20mg/kg (over 2h)6h
Gram +ve bacteria –more effective(Staph. aureus)
Bony infections - osteomyelitis, sinusitis, periosteitis, periodontitis Aspiration pneumonia, Lung abscess
Clindamycin6mg/kg 6h oralIV over 30min,IM 12h10 -20mg/kg 8h
Gram - ve bacteriaLess effective
Untoward Effects of Lincosamines
• Diarrhoea (superinfection)
• Pseudomembranous colitis due to Clostridium difficile
which produces enterotoxin(Tx –metronidazole)
• Hypersensitivity (rare);
• Granulocytopenia, thrombocytopenia,
• Stevens -Johnson Syndrome
(can occur, but not common)
Antibact Rx Dose& Route
a wide range of G(+)& (-) Salmonella Shigella, V . cholerae H.influenza Bordetella pertussis Brucella, Rickettsia, anaerobic bacteria
Enteric fever Bacterial meningitis H.influenza,N.meningitidis Strep. Pneumoniae Anaerobic infectionsRickettsial infection(typhus fever, Q fever
Brucellosis
IV 1g every 6 hours for 4 weeks in enteric fever Chloramphenicol sodium succinate (1g vial) I.M, I.V
Orally - Chloramphenicol 25mg/kg/D(250 - 500 mg) 6 - 8 hourly
less effect on Staphylococcus
Ophthalmic infection Ear
Eye drop- 2-6 HEar drop- 6H
Untoward Effects
less selective toxicity; may inhibit protein synthesis of
mammalian tissues
1. Haematological toxicity - bone marrow depression
(a) true toxic reaction - dose related, common with prolong therapy
or large dose
- anaemia, leucopenia, thrombocytopenia
(b) Idiosyncratic manifestation - not dose related (occurs in
genetically susceptible patients)
- aplastic anaemia --- can be fatal
2. Grey (gray) syndrome (Gray baby Syndrome)• in premature and newborn infants• due to ineffective conjugation & poor renal excretion with dose above 50 mg/kg/day• dose should be limited to 50 mg/kg/day in full term
infants and 25 mg/kg/day in premature infants
3. Superinfection (oral or vaginal candidiasis) due to alteration of normal microbial flora
4. Haemolysis in G6PD deficient patients (dose-related)
Antimicrobial spectrum Theraputic advantage Dosage
Mainly active against Gram - ve bacteria
(Pseudomonas, Shigella, E.coli, Proteus, H.influ,
Brucella, Klebsiella)active against some
Gram +ve
Mycobacteria (Streptomycin, Amikacin, Netilmicin, Kanamycin)Anaerobic bacteria are
resistant to aminoglycosides
UTI G -ve bacillary infect:GonorrhoeaBowel sterilizationTopical –wounds,burns,dermatitisIntestinal amoebiasisTB
Genta IV,IM 7-8 mg/kg/D1,then 5mg/kg 12H Neonate5-7.5mg/kg/d 24H Streptomycin IM 20-30mg/kg (max:1G)ODAmikacin IV,IM Prem -15mg/kg/D D17.5mg/kg OD Term-15mg/kg/D OD 1 wk to 10yr -15 mg/kgNetilmicin IV,IM 1wk-10yr= 8mg/kg/D1 then 6mg/kgOD ,>10yr = 7 in D1 then 5mg/kg Neonate5 mg/kg/D OD
Unwanted effects1. Ototoxicity• irreversible results from progressive destruction of vestibular or
cochlear sensory cells(a) Vestibular dysfunction (Gentamicin, Streptomycin, Netilmicin)(b) Auditory dysfunction – Kanamycin , Amikacin (potent diuretics potentiate ototoxicity) 2. Nephrotoxicity • due to accumulation of aminoglycosides in the proximal tubular
cells
4. Others• rare - hypersensitive reactions• vague feelings of paraesthesia of the lips or circumoral region• prolong use -- superinfection, diarrhoea, malabsorption
can occur with neomycin
3. Neuromuscular blockade (reversible)due to inhibition of prejunctional release of ACh(Aminoglycosides potentiate d-tubocurarine)
I. First Generation Quinolones• Nalidixic acid II. Second Generation Quinolones• Norfloxacin• CiprofloxacinIII. New fluoroquinolones• Gatifloxacin• Moxifloxacin
• MOA• Bactericidal• Block bact synthesis by inhibiting bact DNA gyrase and
topoisomerase• Antibact spectrum--
E.coli,Salmonella,Shigella,Enterobacter,Campylo-bacter,Neisseria
Pseudomonas(Ciprofloxacin)
Staph( not MRSA)
Strep,Chlamydia,Mycoplasma,Legionella,Mycobact
Clinical Uses of Fluoroquinolones1. Urinary tract infections (Norfloxacin)2. Prostatitis (Norfloxacin, Ciprofloxacin, Ofloxacin)3. Sexually transmitted diseases
(Not for Treponema pallidum )4. Gastrointestinal & abdominal infections
– Traveller’s diarrhoea– Shigellosis (Norfloxacin, Ciprofloxacin, Ofloxacin)– Enteric fever (Ciprofloxacin, Ofloxacin)
5. Bone, Joint & soft tissue infections( osteomyelitis caused by Staph &G-ve rods)
6.Others
M.avium complex (in AIDS)
MDR TB
7. Meningococcal Prophylaxis
• Dosage
Ciprofloxacin- oral= 5-10 mg/kg 12H
IV = 4-7 mg/kg 12 H
Norflox = 10 mg/kg 12H
Prophylaxis
15 mg/kg oral single
Side effects
Generally well tolerated• nausea, abdominal discomfort, diarrhoea, headache,
dizziness, allergy, photosensitivity• cartilaginous erosion in foetus and children (arthropathy)
and tendonitis --- limited used in children age <14 years and pregnancy
• Increse BUSE• Transient ↑ in Liver enzymes,Bilirubin• Disturbance in vision,taste and smell• Risk of haemolysis in G6PD def;
• Drug interaction- Cipro,Ofloxa ,Peflox inhibit the metabolism of Theophylline
• Bacteriostatic• Competitive inhibitor of dihydropteroate
synthase which is responsible for the incorporation of PABA (para-aminobenzoic acid) which is essential for the formation of folic acid (pteroylglutamic acid)
Antibact spectrum Theraputic application
G+ve and –ve except pseudo,proteus
Chlamydia trachomatisToxoplasma
1.Urinary tract infection
2.Other Gram-positive and Gram-negative infections (in penicillin allergic patients)Trachoma & conjunctivitis (Sulfacetamide)Ulcerative colitis -SulfasalazineLocal infections: Dermatitis – Sulfapyridine Burns - Sulfamylon, Silver Sulfadiazine
Pneumocystis carinni Prophylaxis for HIV associated opportunistic infection
Malaria parasites Chloroquine resistant malaria (Pyrexine = Sulfadoxine + Pyrimethamine)
Untoward Effects
1. Renal toxicity• a local reaction with short-acting sulfonamides (high doses)• may precipitate in the urine(obstruction,haematuria)2. Haemopoietic reactions Anaemia-haemolytic/aplastic,granulocytopenia H’lysis in G6PD def: Neonatal jaundice in new-born babies(especially in last trimester—Haemolytic jaundice)
47antimicrobial agents III
3. Allergic reactions --- skin rashes, exfoliative dermatitis, photosensitivity --- more severe with long acting sulfonamides
• Stevens-Johnson Syndrome- mucosal, dermal, genital and occular lesions; joint pain, high fever, oedema, ulcerations of the lips and tongue- erythema multiforme on skin of hands and thighs- severe urethritis and balanitis in males
48antimicrobial agents III
Untoward Effects
• Synergists of Sulfonamides1. Trimethoprim 80mg + Sulfamethoxazole 400 mg
MOA of Cotrimoxazole• Sulfonamides are the competitive antagonist of PABA. They
inhibit the incorporation of paraaminobenzoic acid(PABA) to folic acid.
• Trimethoprim is a dihydrofolic acid reductase inhibitor. It prevents the reduction of dihydrofolate to tetrahydrofolate.
• Inhibition of two consequent steps in the synthesis of DNA and RNA of bacteria when a sulfonamide and trimethoprim are used together.(Sequential Blockade)
• Two bacteriostatic compounds act synergistically and become bactericidal
antimicrobial agents III 51
Antibacterial spectrum Rx uses Dosage
Streptococci, Staphylococci, NeisseriaE. coli, Salmonella, Shigella, Enterobacter Proteus, Klebsiella, Brucella, Chlamydiaexcept Pseudomonas aeruginosaPneumocystis carinii
(1)Urinary tract infections(2) Respiratory tract infections(3) Gonococcal infections (4) Enteric fever (5) Malaria (CQ resistant falciparum malaria)(6) Brucellosis(7) Pneumocystis carinii infection in AIDS Patient
TMP 1.5-3mg/kg 12H IV ,Oral PCP Tx 250mg/m2 stat
150mg/m 2 8H
Prophylaxis for UTI- 5 mg/kg oral PCP- 5mg/kg 3days/wk
Untoward effects- Same as S’.Megaloblastic A with prolonged Rx
Cont - Synergists of S’
2. Pyrimethamine also an inhibitor of DHFA reductase enzyme of malarial parasites and toxoplasmaPyrexine (or)
Fansidar = Sulfadoxine 500 mg + Pyrimethamine 25 mg
Therapeutic Uses --- Malaria, Toxoplasmosis
3. Tetracycline• in combination with sulfonamides produce
synergistic effects because both are bacteriostatic drugs
4. Penicillin:• although bactericidal, it produces a
synergistic effect when used in combination with sulfonamides.
Drug Interactions with Sulfonamides
• warfarin, sulphonylureas, diphenylhydantoin
(1) potentiation of action of other drugs due to competition at plasma protein binding site (drug displacement interaction)
(2) inhibition of metabolism
55antimicrobial agents III
Metronidazole(Nitroimidazole-antiprotozoal)
• MOA - Effect on nucleic acid metabolism
Potent antibacterial ,anaerobes , Bacteroides and Clostridium sp• Theraputic advantage • Anaerobic or mixed intraabdominal infection- Extraluminal amoebiasis - 30-50mg/kg/d oral- Amoebic liver abscess - 7.5to 30mg/kg iv 12H/8H x7-10 days
- Trachomonal vaginitis- Clostridium defficile colitis- Brain abscess
• Side-effects- GI disturbance,metallic taste,peripheral neuropathy,
seizures
Interacting drugs- Alcohol- Warfarin increase anticoagulant effect
(enzyme inhibition)
TETRACYCLINESBroad spectrum bacterostatic
Antimicrobial spectrum Tx - Infections with
Gram+ ve and –ve BacteriaRickettsiae,Mycoplasma,ChlamydiaSpirochetes (Treponema, Leptospira, Borrelia), Vibrio choleraeH.pylori E.histolytica Malaria parasites less effect on Strep, Staph, Pneunococci Not effective against – Pseudomonas,Proteus, Salmonella
Rickettsia Mycoplasma pneumonia Non-specific urethritis Trachoma,Syphilis,STDLeptospirosis, LymesCholera Combination Tx GU/DUAmoebiasisCQ resistant P.f
Dosage
oral –250-500 mg/ 6H( >8yrs) Eye ointment- apply 8H
Anti-TB1st lineIN(A)H
Rifampincin*
PZAEthambutolStreptomycin
10mg/kgoral od
TBM 15 -20mg/kg10-15 mg/kg
20-30mg/kg oral
25mg/kg oral20-30 mg/kg IM
Adverse effectsPeripheral neuro( recommended-B6 20-30mg/D )Hepatotoxicity,Rash
Hepatitis.nephritis,ITP
Hepatitis,Interstitial nephritisRetrobulbar neuritis,yellow-green colour vision defectOtotoxic,Nephrotoxic
2nd lineCapreomycinCycloserineEthionamideAzitho/clarithromycinQuinolones
20mg/kg oral5-10mg/kg oral15mg/kg oral
OtotoxicityCNS toxicityHepatotoxic
Bactericidal drugs
- Penicillins- Cephalosporins-Other --lactam antibiotics- Aminoglycosides- Rifampicin- Fluoroquinolones- Cotrimoxazole- Metronidazole
Bacteriostatic drugs
- Chloramphenicol - Tetracycline - Erythromycin- Clindamycin - Lincomycin - Sulphonamides
Broad-spectrum Antibiotics
- Broad-spectrum penicillins (Aminopenicillins and Antipseudomonal penicillins)
- Coamoxiclav- the second, third and fourth generation Cephalosporins- Tetracyclines- Chloramphenicol- Rifampicin
- Cotrimoxazole
Antipseudomonal Agents
- Carbenicillin, Carbenicillin indanyl- Ticarcillin- Piperacillin- The third generation cephalosporins- The fourth generation cephalosporins- Amikacin, Netilmycin- Fluoroquinolones- Polymyxin - topical application for wounds
Anti-infective agents which can be used for Staphylococcus
- Penicillinase resistant penicillins(Cloxa,Flucloxacillin)- AUGMENTIN (Coamoxiclav) (Amoxicillin + Clavulanic acid)- TIMENTIN (Ticarcillin + Clavulanic acid)- UNASYN (Ampicillin + Sulbactam)- ZOSYN (Piperacillin + Tazobactam)- Some first & second generation Cephalosporins - third & fourth generation Cephalosporins- Erythromycin- Vancomycin- Rifampicin- some fluoroquinolones
Anti-infective agents for anaerobic bacteria
- Metronidazole- Lincomycin, Clindamycin- Chloramphenicol- Fluoroquinolones- the third & fourth generation cephalosporins
Empiric antimicrobial Rx(based on site of Infection)
SOI Pathogens DOC Alternative
Meningitis -Neonate
Ampi+3rd Cepha Ampi(Cotri)+3rd Ce (+Aminogly)
-Child C/Pen +Cefotaxime or Ceftraxone
C.Pen+Chloram
Pneumonia-Neonate Ampi+3rd Cepha
-Younger child C/PenCefotaxime or Ceftraxone
Ampi -sulbactam
-Older child Macrolides Quinolines
SOI Pathogens DOC Alternative
IE acute
Vancomy+Genta Pen-resistant pen+Genta
SBE Pen G+ Genta Vanco+ Genta
Septic arthritis Ceftriaxone Ampi+Sulbactam
Acute OM,Sinusitis Amoxil Amoxil+SulbactCefuroximeTMP-SMZ
Cellulitis Pen-resistant pen VancomycinClindamycin
Peritonitis 3rd cephalo+Metro Carbapenem
Septicemia
(Granulocytopenia)Sepsis d/t UTISepsis d/t GITNeo sepsis Early --
Late -
3rd cephalo+VancoAntipseudo+Amino3rd cepha/ceftazidime3rd cephalo±Genta3rd cephalo +MetroAmpi+GentaAmpi+Genta+Clox/Van3rd Cephalo
STSA
Antiviral drugs1.NucleosideAnalogues*(synthesis of DNA&RNA)
Acyclovir*20mg/kg iv100mgodx 5 dGinclovirCidofovir
HSV1,2VZVCMVEBHHV6Hepa C
Herpes-oral,genital HS-EncephalitisVaricella(immu ↓)CMV retinitis,Pneumonitis
2.AmantadineRimantadine(penetration of cell)
100mg OD200mg OD
Influenza A,BH1N1,H1N2,H1N3
Influenza A-H1N1
3.Foscanet(DNA &RNAsyn:)20mg/kg iv over 30’
CMV,VZVHSV(Aciclovir resist)
CMV retinitis in HIV p/t
4.ImmunomodulatorInterferon α(inhibit the transcription)Plavizumab
Hepatitis B &CHPVCGDRSV
Chronic hepatitis B &C
RSV Bronchiolitis
5.Ribavarin(aerosol-20mg/ml 12-18hrly)(oral5-50mg)
RSV RSV BronchiolitisPn’ia
6.NeuraminidaseInhibitors(release of virus)Zanamivir/Oseltamivir
Influenza A & B Influenza A & B
7.AntiretroviralNRTI-competative inhibit: activated i/c byphosphorylationZidovudine(2mg/kg)Didanosine(ddI )Dideoxycytidine(ddC)Stavudine(d4T)Lamivudine(3TC) Adefovir
HIV
Hepa B
Side effects
A,neutropenia,myopathy
Pancreatitis,Periph neuro,DPeri neuro,pancreatitis,rashPeri neuro,A,LipoatrophyHeadche,N,abdo pain
NNRTI-inhibit viral replication by direct binding to RT Nevaripine120mg/m2 daily oral
HIV
Rash,Steven syn,Hepatitis
Protease Inhibitors-Interfere with post-translational processing of HIV precursor proteinsEg.Ritonavir IndinavirDose-500mg/m2 8H oral
Asymptomatic hyper bili-rubinemia,GI disturbanceSkin,hair changes
Major adverse effects
1. Nephrotoxicity eg. Foscarnet, Amantadine 2. Neurotoxicity - seizures eg. Nucleoside analogues, Amantadine(high dose),INFs 3. E imbalance- hypo K,hypo &hyper Ca eg.Foscarnet 4. Hypo & hypertension eg. INFs5.Bone marrow supression- neutropenia eg. INFs,Aciclovir6.GI disturbance eg.INFs
7. Flu like syndrome- F,fatigue, myalgia• eg. INFs
8. Teratogenic
eg.Aciclovir,Ginciclovir
9.Hepatic steatosis
eg. NRTI
How Does These Drugs Works…
Management in babies born to infected mothers
Scenarios Therapy
- HIV mother on HAART
- HIV mother started on zidovudine at 14-28 weeks gestation
Zidovudine
2mg/kg/dose QIDx 6wks OR
4mg/kg/does BDx6 wks
-HIV mother at delivery with inadequate prophylaxis (<4 weeks)
-Infant born to HIV mother without prophylxis
Single dose Nevirapine
+ Zidovudine
2mg/kg/dose QID 6 weeks
OR4mg/kg/does BD 6 weeks
Antifungal agentsbased on route of administration
1.Systemic
For deep fungal infection(oral/parenteral)
Amphotericin B (I.V) Flucytosine (oral)Imidazoles and Triazoles -Ketoconazole, Itraconazole-Fluconazole
For superficial fungal infections Griseofulvin (Oral)
2.Topical antifungal agents Clotrimazole (CANESTEN)- Miconazole-Econazole-Ketoconazole-Nystatin (MYCOSTATIN)
Miscellaneous MYCODERM
Drug Dose & Preparation
Rx Side effects
Ampho.B(fungistatic/fungicidal)
IV 1.5 mg/kg/dIntrathecalOral 100mg 6hCream,ointmentLocal installation
Local &systemic-Meningitis,Endocarditis due toCryptococcusCoccidioidesHistoplasmaCandida, BlastomycesAspergillus
HypersensitivityNephrotoxicLiver impairmentAnaemia,Hypo-k
Griseofulvin(fungiststic)
5-7mg/kg oralTopical
Broad spectrumMicrosporum,Epidermophyton, Trichophyton (Dermatophytosis) Superficial ringworm infestation (Tineacaptis,Tinea corporis,Tinea pedis)
PhotosensitivityPorphyriaHeadacheHepatitis
ImidazoleKetoconazoleMiconazole(broadspectrum)
5mg/kg oral,cream7.5-15mg/kg iv 8HTopical,vg cream
Supercial & DeepCandidaDermatophytes(Teniasis,Pityriasis versicolar)Seborric dermatitis
N,V,Pruritus,Rash,HepatitisFluid & H2O retensionGynaecomastia
Fluconazole
Itraconazole
Clotrimazole(fungistatic)
(penetrate readily toCSF) 3-6mg/kg oral /iv2-4mg/kg oral
Vaginal tab1%cream,oral
DermatophytosisCandidasisCryptococcusAspergillosis
CandidasisDermatophytosis
Itchiness,burning,Rash
No serious systemic side effect
Nystatin(fungistatic/cidal)
Cream,ointmentVg tabOral
Candidasis(oral thrush,GI,vaginal,Skin)
No systemic side effect
Summary
• Ampho B –drug of choice except candida• Griseofulvin –drug of choice for dermatophytes except aspergillus• Fluconazole ,Miconazole _ for candida/dermatophytes• Nystatin _ for candida
Anti-protozoal drugs
• Antmalarial drugs1. 4 Aminoquinolones CQ2. 8- Aminoquinolones Primaquine3. Arylamino alcohols Quinine, Mefloquine4. Anti-folates Sulphadoxine,Pyrimethamine5. Quinghaosu Artemisin
Blood schizontocidesCQQuinine
Mefloquine
Alleviate symptoms-a/c attackOral 10mg/kg x 3dOral 8.3mg/kg x7-10 dIv 20mg/kgx4h,8.3mg/kg 8H15mg/kg stat,10mg/kg a/f 6-8hr(Prophylaxis- 5mg/kg wkly)
Photosensitivity,n,v,reti-nal damageTinnitus,HglycemiaHypotension(cinchonism)Postural HypotensionCardiac conduct defect
Artesunate
Artemether
Oral 5mg/kg D1,2.5mg/kg D2-D3IV,IM 2mg/kg then 1 mg/kg 6HIM 3.2mg/kg stat 1.6 mg/kg daily
Relatively safe
SporontocidesPyrimethaminePrimaguineProguanil
Prophylaxis
Tissue schizointocides
PyrimethaminePrimaquineProguanil
To prevent parasites becoming established in the Liver25mg tab*0.3mg/kg daily X14 d3.5mg/kg oral
CI –PregnancyH’lysis in G6PDdef,BM˅,alopecia
HypnozoiticidesPrimaquine
To prevent relaspe
GametocidesPrimaquine
0.7mg/kg od
Mgt of Pl.falciparum(Paed:protocol)
• Uncomplicated
1st line-
Artesunate odx3D
Mefloquine od
Alternate:
Artemether/lumefantrine
2nd lineQunine
Clindamycin
• Complicated
1st line
IV Artesunate bdod
2nd line
IV Quinine oral
Doxycycline/Clindamycin
Antihelminthics Drugs Rx advantage Mode of Action Adverse Effects
Mebendazole50-100mg BDx 3D
TrichuriasisEnterobiasisAscariasis
Broad spectrum, inhibit microtubules, glucose absorption immobilization death
Worm migration (rare)
Albendazole 200-400mg single
TrichuriasisEnterebiasisAscariasisHookworm
Pyrantel pamoate10-11mg/kg ODRepeat in D14
TrichuriasisAscariasisEnterobiasis
Depolarization of the neuromuscular (Neuromuscular blocking agent)
Mild abdominal pain
Levamizole3mg/kg
Repeat in 1 wk
AscariasisEnterobiasis
Hookworm
Immunostimulants Paralysis of the muscle of the worm – expelled by peristalsis
Abdominal pain
Ivermectin 0.15-0.4mg/kg
Hookworm, filariasis, strongyloides
Membrane hyperpolarization ; paralysis
Abdominal distension , wheeze, TOC
Thiabendazole 200-400mg OD
Hookworm
• References:- Paed:Protocol (2nd edition)- Nelson Text Book (19th edition)- Basic and Clinical Pharmacology(11th edition)- Basic Medical Science(Easterbrook-3rd edition)
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