Anti-infective drugs: Antibacterial drugs Anti-T.B drugs Antifungal drugs Antiviral drugs

2. 
1. Antibacterial drugs
2. Anti-T.B drugs
3. Antifungal drugs
4. Antiviral drugs
Anti-infective drugs

3. 
Susceptibility Location Concentration
Cost
Adverse
effects
Selecting antimicrobial drug

4. 
 Drugs that kill or inhibit the growth of bacteria .
 The Action of Antimicrobial Drugs :
A . Antibacterial drugs
1. Cell wall
inhibitors
2. Inhibitors of
cell membrane
3. Inhibitors of protein
synthesis
4. Inhibitors of
nucleic acid
A) B-lactam
antibiotics
Amphotersin B Aminoglycoside Quinolones
Penicillins
Cephalosporins
Carbapenems
Monobactams.
Azoles Tetracyclines
Lincomycin
Rifampin
B) Non B-lactam Polymyxins Macrolides Sulfonamides
vancomycin
bacitracin
Chloramphenicol Trimethoprim

5. 

6. 

7. 
 Divided into four groups :
 Use : Penicillin antibiotics were among the first medications
to be effective against many bacterial infections caused by
staphylococci and streptococci.
1. Penicillins
Natural
penicillins
β-lactamase-
resistant
Aminopenicillins Carboxypenicillins
(Extended spectrum)
Penicillin G
benzathine (I.M)
Dicloxacillin Ampicillin Carbenicillin
Penicillin G
procaine (I.M)
Nafcillin Amoxicillin Ticarcillin
Penicillin V
potassium (Oral)
Oxacillin

8. 
Pharmacokinetics
1. absorption of oral penicillin depend on :
•PH of stomach and intestine.
•Presence of food in GIT.
• Most penicillins should be given on empty stomach to enhance absorption.
• Penicillins that can be given without regard to meals : Amoxicillin , penicillin V ,
amoxicillin / cavulanate .
2. distribution :
• Distributed widely to most areas of the body.
• Poor penetration to CSF ,unless inflammation is present.
• High conc in urine ,so penicillins useful in treating UTIs.
3. metabolism and excretion :
• Metabolized in the liver.
• Nafcillin and oxacillin are excreted in bile.

9. 
 Usally Bactericidal.
 They bind reversibly to several enzymes outside the
bacterial cytoplasmic membrane.
 These enzymes are penicillin-binding proteins (PBPs) ,are
involved in cell-wall synthesis and cell division.
 They cover Gram +ve ,Gram -ve and anaerobic
organisims.
Pharmacodynamics

10. 
Drug interactions ADRs
probenecid : increase plasma conc of
penicillins.
Hypersensitivity reactions : Anaphylaxis
(immediate allergic reaction) Urticarial
rash – Fever - Bronchospasm.
penicllins reduce tubular secretion of
methotrexate in kidney ,increase risk of
methotrexate toxicity.
Serum sickness : is a type of delayed
allergic response appearing 1 to 2 weeks
after exposure to foreign serum.
tetracyclines and chloramphenicol reduce
action of penicillins.
oral penicillins : tongue inflammation
,Nausia ,Vomiting and Diarrhea.
effectiveness of hormonal contraceptive is
reduced when taken with penicillin v or
ampicillin.
Oxacillin : liver toxicity.
acting against aminoglycosides ,shouldn’t
be mixed in the same I.V soluions.
Aminopenicillins and extended-
spectrum penicillins :
pseudomembranous colitis.

11. 
 Co-amoxiclav (Augmentin) is a combination of :
1. amoxicillin (Inhibitor of cell-wall synthesis) and
2. clavulanic acid (a β-lactamase inhibitor).
 In addition to those bacteria that are susceptible to
amoxicillin, most Staphylococcus aureus, 50% of E. coli,
some H. influenzae strains and Klebsiella species are
susceptible to co-amoxiclav.
 Adverse effects : are similar to those of amoxicillin, but
abdominal discomfort is more common.
CO-AMOXICLAV

12. 
 They grouped into generations according to their
effectiveness against different organisms :
2. Cephalosporins

13. 
 Cross-sensitivity : occurs in 10 % of patients
This means that someone who has had reaction to
penicillin is also at risk for a reaction to cephalosporins.

14. 
 Like penicillins ,they inhibit cell-wall synthesis by
binding to bacterial enzymes known as PBPs.
 1st GEN used to treat staph and streptococcal infections
including pneumonia ,skin infections.
 2nd GEN cefoxitin is the only one effective against
anaerobes.
 3rd GEN is DOC for infections caused by Enterobacter
and anaerobic organisms.
 1st and 2nd GEN used as prophylaxis during surgery.
Pharmacodynamics

15. 
Pharmacokinetics ADRs
1. After absorption cephalosporins
are distributed widely and cross
placenta.
2. After I.V or I.M adminstration the
3rd GEN drugs cefotaxime ,ceftriaxone
cross BBB ,CSF.
3. Excreted unchanged by the kidney
with the exception of ceftriaxone
excreted in stool via bile ,this is very
useful in patients with renal failure
1. Seizures
2. bleeding
3. diarrhea.
Ceftriaxone : decrease in prothrombin
activity ,increase risk of bleeding in
patients with :
1. renal impairment ,
2. liver disease ,
3. impaired Vit K synthesis.

16. 
1. The patient receiving cephalosporins who drink alcoholic
beverages ,may experience acute alcohol intolerance ,with
symptoms of headach ,flushing ,dizziness ,nausea ,vomiting
and abdominal cramps within 30 min of alcohol ingestion.
2. Probenecid and uricosuric drug can reduce kidney excretion
of some cephalosporins.
3. Probenecid used to increase cephalosporins plasma conc.
4. Cephalosporins may decrease estrogen absorption ,decreace
efficacy of oral contraceptive.
Drug interactions

17. 
 Provide bactericidal activity against gram –ve bacilli ,some
aerobic gram +ve bacteria ,mycobacteria.
 Aminoglycosides are inactive against anaerobic bacteria.
3. Aminoglycosides
Common aminoglycosides Pharmacokinetics
• Amikacin
• gentamicin
• neomtcin
• kanamycin
• streptomycin
1. absorbed poorly from GIT ,they
usally given parenteraly.
2. disteributed widely in
exteracellular fluid ,they cross
placental barrier ,but don’t cross
BBB.

18. 
 They are bactericidal by Interrupting protein synthesis.
 Resistance duo to :
1. altered binding to ribosomes.
2. destructin of drug by bacterial enzymes.
3. Failure of drug to cross the cell membrane.
 Penicillins used with aminoglycoside ,the cell wall is altered
Allowing aminoglycoside to penetrate the bacterial cell.
Pharmacodynamics

19. 
1. Useful in treating grame –ve bacilli infections.
2. nosocomial infections such as gram –ve bacteremia.
3. peritonitis and pneumonia in critically ill patients.
4. UTIs resistant to penicillins and cephalosporins.
5. infections of eye.
 Sterptomycin : active against mycobaceria including
mycobacterium tuberculosis.
 Amikacin ,gentamicin and tobramycin : active against
enterobacter ,klebsiella ,E.Coli ,pseudomonas aeruginosa.
Uses

20. 
Drug interactions ADRs
Carbenicllin ,ticarcillin reduce effects of
gentamicin if mixed in the same I.V line.
neuromuscular reactions
With neuromuscular blockers : increase
neuromuscular blockade ,increase
muscle relation and respiratory distress.
Ototoxicity
When taking with cyclosporines
,amphotericin B increase risk of renal
toxicity.
Renal toxicity
When taking with loop diuretics
increase risk of ototoxicity.
Symptoms of ototoxicity may be masked
by antiemetic drugs hearingloss may be
irreversible.

21. 
 They include :
 Erythromycin ,azithromycin , clarithromycin ,telithromycin.
4. Macrolides
Pharmacokinetics Pharmacodynamics
1. they are acid-sensitive ,it must be
buffered or have an enteric coating to
prevent destruction by gastric acid.
2. It distributed to most tissues and fluids
except CSF.
3. Macrolides can enter CSF when meninges
are inflamed.
inhibit RNA-dependent
protein synthesis by acting on
ribosome.

22. 
Drug interactions ADRs
Macrolides can increase theophylline
levels ,increase the risk of theophylline
toxicity
,due to reduction of mixed function
oxidase activity.
1. epigastric distress.
2. diarrhea with larg doses.
3. eosinophilia.
4. anaphylaxis.
Uses
It provide a broad spectrum activity against gram +ve ,-ve bacteria Including :
mycobacterium ,mycoplasma ,chlamydia
pneumococci and group A streptococci ,staph.aureus is sensitive to erythromycin
Erythromycin is the DOC for treating mycoplasma pneumonia infection ,and treat
gonorrhea and syphilis in patient who can’t tolerate penicillin G
Clarithromycin used in combination with antacids , PPIs and H-2 blocer to treat
H.pylori-induced duodenal ulcer
telithromycin used against organisms resistant to other macrolides

23. 
 Is effective against penicillin resistant staphylococci and
many anaerobic organisms.
 It well absorbed and penetrate into bone.
 It is indicated in serious conditions where other agent are
contraindicated or ineffective ,notably staphylococcal bone
and joint infection.
 It has particular use in streptococcal toxic shock syndrome
,it reduce toxins production.
5. clindamycin

24. 
 It is used to treat methicillin-resistant S.aureus
(MRSA).
 It should be used only when the culture and
sensitivity test confirm the need for it.
6.vancomycin
Pharmacokinetics Pharmacodynamics
• It is absorbed poorly from GIT ,must
be given I.V to treat systemic infection
,an oral form used in
pseudomembranous colitis.
• Vancomycin diffuse well into pleural
,pericardia ,synovial and ascitic
fluids.
• I.V vancomycin can’t be used in place
of oral vancomycin and vice versa.
• It inhibits bacterial cell-wall synthesis.
• It is active against gram +ve bacteria.
• I.V vancomycin is DOC in patient with
serious resistant staphylococcal
infection ,or who is hypersensitive to
peniciilins.
• Oral vancomycin used for patient with
antibiotic-associated clostridium
difficile colitis who responded poorly
to metronidazole.

25. 
 When vancomycin is used with aminoglycoside it is the DOC
to treat endocarditis in patient who is allergic to penicillins.
Drug interaction ADRs
Vancomycin may increase risk of
toxicity when adminsterated with
drugs toxic to kidney and organs of
hearing ,such as aminoglycoside
,amphotericin B ,cisplatin.
1. Hypersensitivity and anaphylactic
reactions .
2. Drug fever.
3. Eosinophilia.
4. Neutropenia.
5. Hearing loss when given with other
ototoxic drugs.
6. Red man’s syndrome : sever
hypotension may occur with rapid I.V
administration and may accompied by
a red rash with flat and raised lesions
on the face ,neck ,chest and arms.

26. 
 They are Beta-lactam antibiotics that include:
1-Meropenem (meronam).
2-Imipenem-cilastatin (tienam).
7. Carbapenems
Pharmacokinetics Pharmacodynamics
Cilastatin prevents impinem
metabolism in tubules of kidney by
dihydropeptidase enzyme.
1.They are Broad-spectrum
Bactericidal Inhibiting bacterial cell
wall synthesis.
2.Tienam is broadest spectrum found
to date !

27. 
Uses Drug interaction
1.Imipenem effective against G+ve
aerobics and inhibit most
Enterobacter species.
2. Selective use: Imipenem used alone
to treat serious health-care acquired
infections and in immune-
compromised patients caused by
aerobic and anaerobic organism.
3. Meropenem used in treat Intra-
abdominal infection and bacterial
meningitis.
1. probenecid with imipenem-
cilastatin increase serum level of
cilastatin but only slight increase in
imipenem.
2.probenecid cause itrapenem and
meropenem to accumulate to toxic
level.
3.combination of imipenem-cilastatin
with aminoglycosides is synergistic
against Staph. Aureus.
4.cross sensitivity with penicillin.
5.must adjust dose in patients with
renal failure.

28. 
 Aztreonam Is the only one available.
8. Monobactams.
Pharmacodynamics Uses
1. bactericidal activity inhibiting cell-
wall synthesis.
2. narrow spectrum against G-ve
aerobic bacteria
1. Gram –ve aerobic bacteria.
2. effective against E.coli, Enterobacter,
klebsiella pneumonia and H.influenza.
3. Treat complicated and non-
complicated UTI.
4. Lower respiratory tract infection.

29. 
 Shouldn’t be used alone as Empiric therapy.
ADRs
1. hypersensitivity and skin reaction.
2. hypotension.
3. Transient ECG change.
4. Transient increase in serum liver enzymes level.

30. 1st Generation 2nd Generation
Nalidixic acid. (negra) Ciprofloxacin
Levofloxacin
Moxifloxacin
Norfloxacin
Ofloxacin
9. Fluoroquinolones
Pharmacodynamics. Use
Interupt DNA
synthesis during
bacterial replication by
inhibiting DNA
gyrase.
1- Treat of UTIs.
2- Cipro and levofloxacin are used to treat Lower
respiratory tract infection, skin and bone.
3- Moxifloxacin is used to treat acute bacterial sinusitis
and moderate community acquired pneumonia.
4- Norfloxacin used to treat UTI and prostatitis.
5- Ofloxacin treat Selected STDs and lower RTIs.

31. 
ADRs Drug interactions
1- Diarrhea.
2- abdominal pain.
3- erosion of cartilage lead to
tendon rupture so not used in
patients under 18 years due to
arthropathy.
4- should be avoided during
pregnancy
5- moderate to sever phototoxic
reactions so use sunblock.
1. Antacids containing magnesium
or aluminum reduce absorption of
fluoroquinolones.
2. Cipro,nor and ofloxacin interact
with xanthine derivatives as
aminophylline and theophylline
increasing their levels leading to
theophylline toxicity.
3. probenecid reduce their kidney
elimination leading to increase
serum level and half-life.

32. 
Mycobacterium T.B characteristics:
1- T.B multiplies slowly and long period treatment
regiments are required in resistant strains.
2- Combination chemotherapy is needed to decrease risk of
resistance which is due to non-adherence to complex
regiment of 4 or more drugs.
Anti-tuberculous drugs

33. (Isoniazid-rifampicin-
pyrazinamide) Co-
formulation. For 8
weeks.
Six months of therapy
are needed in case of
pulmonary T.B.
If other drugs are used
(ethambutol) 9 months
maybe needed.
If CNS or extra
pulmonary involvement
is found more than nine
months will be needed.
T.B treatment regiments

34. 1st line 2nd line
INH Fluoroquinolones
Ethambutol Streptomycin
Pyrazinamide
Rifampicin
T.B Drugs

35. 

36. 

37. 

38. 

39. 
Made By:
Omar Hesham Abd Elaziz
Thank you !