This document discusses various classes of anti-bacterial agents including aminoglycosides, tetracyclines, chloramphenicol, macrolides, and others. It provides details on specific drugs within each class, including mechanisms of action, dosages, side effects, and common uses. It also outlines treatments for some common infections and interventions to consider when administering antibiotics.

1. Pharmacology
Anti-bacterial agents -part 2
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2. Aminoglycosides
• This group of AB’s interfere with protien
synthesis in the bacterial cell.
• Have wide antibacterial range.
• Streptomycin is effective against
Myobacterium tuberculosis.
• All consider Ototoxic and nephrotoxic.
• If systemic effect required should be given as
injection.

3. Aminoglycosides
• 1- Gentamycin:
• Widely used especially in severe infections by
staphylococci and gram –negative germs.
• I.V , I.M
• 3 times daily,
• Blood level of gentamycin should be measured
closely every 48 hour , if its too low the drug is
not effective, if its high (10mg/L or higher)
ototoxicity may result.

4. Aminoglycosides
• Renal damage may occur if given with
fruesmide.
• Should be avoided during pregnancy, as it is
ototoxic to the fetus.

5. Aminoglycosides
• 2- Neomycin :
• Poorly absorbed from GIT and it become toxic if
given systemically.
• Not given orally.
• Used to sterilize the gut before surgeries
• As ear or eye drops
• As topical creams and ointments

6. Aminoglycosides
• 3- Streptomycin :
• Rarely used for infections
• Main use is for resistant Tuberculosis.
• Given as I.M injection

7. Tetracyclines
• This group include:
• Tetracyclin, oxytetracyclin,
chlortetracyclin
• Orally 4 times a day.
• Tetracyclin can be given a s I.V but mostly by I.V
infusion bcz its irritating to the vein.
• The presence of antacids, milk or salts render
(decrease) the absorptions of them.
• Wide antibacterial range.

8. Tetracyclines
• Main uses: bronchitis, pneumonia, urethritis,
abortus fever.
• Long period treatment of acne.

9. Other Tetracyclines
• 1- Doxycycline (Doxydar®)
• Excreted slowly so given as a single dose.
• Can be used when renal function is impaired.
• Used for prevention of malaria.
• 2- Minocycline:
• broad spectrum and effective against niesseria
meningitis.

10. Tetracyclines
• Side effects:
• NVD
• Gastric irritation
• Can cause damage and discoloration in teeth so
should be avoided in pregnancy and in children
younger than 12 years
• Tetracyclines except doxycycline don’t give to
patients with renal impairment.

11. Chloramphenicol
• Broad spectrum like tetracyclines
• Given orally
• Can cross CSF so can be used to treat meningitis
• Treat typhoid, and typhoid fevers
• Can be used for ear or eye infections as drops.
• Side effects: toxic to the bone marrow
• Can cause anemia

12. Macrolides
Erythromycin
• Bacteriostatic , broad spectrum.
• Taken orally, don’t cross CSF
• Taken with food to avoid nausea.
• Infusion as erythromycin lactobionate.
• Side effects: diarrhea, vomiting and rarely
jaundice

13. Macrolides
Clarithromycin
• Effective against hemophilus influenza, and used
for eradication of helicobacter pylori.
Azithromycin
• Same as previous, given once daily.

14. Other antibiotics
Clindamycin (Dalacin-c®)
• Taken orally
• Penetrate the bones and can treat bone
infections.
Polymyxin
• Taken locally (topical) for infections such as
otitis media.

15. Other antibiotics
Sodium fusidate
• Effective against resistant staphylococci
• Usually combined with other AB’s.
• High doses may cause jaundice.
Vancomycin (Vancocin®)
• Severe staphylococcal infections and to treat
pesudo-membranous colitis.
• Slow I.V infusion
• Ototoxic and nephrotoxic

16. Other antibiotics
Teicoplanin
• Severe staphylococci infections, dialysis-associated
peritonitis and endocarditis.
Linezolid
• Effective for pneumonia and soft tissue infections
caused by gram negative bacteria.
• Orally or I.V
• Side effects: change in taste, tongue discoloration
• Shouldn’t used in breast feeding women.

17. Other antibiotics
Dalfopristin with quinupristin
• Only in patients who failed to responed to other
medications in treating serious and severe
infections.
• IV into the central vein
• Contraindicated in pregnancy, breast feeding,
liver disease, heart disease and renal disease.

18. Treatment of common infections
Common cold
• NSAIDs
• Paracetamol
• Antihistamines
• Inhalations
Sore throat
• Viral sore throat don’t require AB’s
• Bacterial ones can be treated with phenyl-benzyl
penicillin 4 times a day

19. Treatment of common infections
Bronchitis
• Chronic bronchitis is best treated with
amoxicillin 3 times or doxycycline once.
Pneumonia
• Sputum and blood culture required
Meningococcal meningitis
• Benzyl penicillin I.V every 4-6 hours
• Ceftriaxone used when we doubt the bacterial
type.

20. Treatment of common infections
UTI
• Usually caused by E.coli
• Treated by:
• Trimethoprim twice daily for 5 days
• Cefadroxil for 3 days
• Norfloxacin twice daily
• In serious infections cefuroxime can be added

21. Treatment of common infections
Meningitis in neonates
• Treated with gentamycin and ampicillin
• Also can be treated with new cephalosporins
ceftriaxone or cefotaxime
Methicillin-resistant staphylococcus
Aureus (MRSA)
• High degree of hygiene should be maintained.
• Wounds require cleaning and local application of
antibacterial agents.
• Vancomycin is effective against it.

22. Treatment of common infections
• Bacterial resistant to antibiotics
• Those resistant organisms produced by mutations,
by modifying it own DNA or take a resistant DNA
from another organism
• Reduce bacterial resistant:
• 1-AB’s given only when nessecary
• 2-AB’s given with adequate doses
• 3-don’t use AB’s as prophylaxis except in patients
with rheumatoid fever, prevent endocarditis or
major surgeries with high risk of sepsis.

23. Interventions in AB administration
• Oral penicillins and tetracyclins should be given 30 min
before meals
• Erythromycin, sodim fusidate, and metronidazole given
with or after meals.
• I.V AB’s given as bolus
• Some AB’s which need I.V infusion are unsuitable in
some solutions like ampicillin lose it activity in dextrose
solution.
• Gentamycin inactivated if given with penicillins.

24. Interventions in AB administration
• When making solutions for injection avoid
contaminations of hands due to risk of contact
dermatitis.
• Hand washing before and after giving the
injection.
• Gloves should be used for I.V injection to avoid
contamination with the blood.