Choice of Antimicrobials..

Antimicrobials contraindicated in Children & baby

1. Sulphonamide -------> Kernicterus in newborn
2. Tetracycline ---------> Teeth discoloration & bone deformity 
3. Chloramphenicol ---> Grey-baby syndrome
4. Quinolones ----------> arthropathy ( never used if <18>



In pregnancy

1. Penicillin
2. Cephalosporin
3. Erythromycin ---> especially if the previous are contraindicated or there is urogenital
     chlamydial infection



In gonorrhea

1. Penicillin
2. Ceftiaxone (single dose)
3. Quinolones ( Ofloxacin & Levofloxacin )
4. Spectinomycin ( single dose )



Urinary Tract Infections

1. Co-Trimoxazole (sulfamethoxazole 400mg + Trimethoprim 80mg)
2. Norfloxacin
3. Amoxicillin
4. Rifampicin


*** UTI : usually caused by Gram -ve bacilli.



Typhoid Fever

1. Amoxicillin
2. Ciprofloxacin
3. Co-trimoxazole
4. Chloramphenicol (before Ciprofloxacin introduced, not preferred now)
5. Ceftriaxone (in resistant cases)



Biliary tract infection

1. Cefoperazone
2. Ceftriaxone
3. Doxycycline
4. Rifampicin


*** They're excreted in bile



In Brucellosis

1. Drug of choice : Doxycycline + Rifampicin/Aminoglycosides
2. Alternatives : Chloramphenicol + Aminoglycosides/Co-trimoxazole



In meningitis (as they cross BBB)

1. 3rd & 4th generation Cephalosporin
2. Chloramphenicol
3. Penicillin -----> crosses BBB only when meninges is inflammed
4. Rifampicin -----> prophylaxis



For Gram -ve, especially Pseudomonas

1. Carbenicillin, Ticarcillin
2. Ceftriaxone, Cefoperazone, Cefipime ( 3rd & 4th gen Cephalosporin)
3. Quinolones
4. Aztreonam, Imipenem
5. Aminoglycosides



Anerobic infections

1. Clindamycin
2. Cefoxitin
3. Chloramphenicol
4. Imipenem
5. Metronidazole ----> also effective as tissue amebicides, eradicating trophozoites but not the
    cysts. Also, against T.vaginalis, G.lamblia...... also used in therapy of peptic ulcer caused by
    H.pylori.



Bacterial endocarditis

Gentamycin + Penicillin (or Vancomycin)



MRSA & ORSA

1. Vancomycin
2. Rifampicin



Bone infections

1. Cloxacillin  & other penicillinase resistant penicillin
2. Clindamycin
3. Cefazolin, cefoperazone, ceftriaxone
4. Ciprofloxacin
5. Gentamycin, Tobramycin
6. Vancomycin
7. Tobramycin



For penicillinase-producing Staph

1. Cloxacillin & other penicillinase resistant penicillin
2. Cephalosporin
3. Clindamycin
4. Co-Trimoxazole
5. Ciprofloxacin or other Quinolones
6. Erythromycin



Drug-induced Pseudomembranous Colitis

Treatment :
1. Vancomycin
2. Metronidazole
3. Cholestyramine ----> to bind toxin.

***** Causes <------ Clindamycin & broad spectrum antibiotic            
Important drug interactions

1. Enzyme inhibitor : Erythromycin, Chloramphenicol, Quinolones, Isoniazid (INH)
2. Enyme inducer : Rifampicin
3. Tetracycline & Erythromycin -----> increase risk of Digoxin toxicity.



Reference : Lecture Notes in Pharmacology by Professors of Pharmacology, Ain Shams School of Medicine, Cairo.