Macrolides, Lincosamides, Phenicols, Pleuromutilins

Question 1

Macrolides: Overview

Answer 1

• inhibition of 50S protein synthesis
• Bacteriostatic!! (Can become bacteriocidal in lung in higher conc.)
• Used in respiratory tract infections induced by Mycoplasma and anaerobic infections induced by fastidious anaerobic bacteria (foot rot, oral cavity infections , bite wound)
• Resistance: (brachyspira is resistant)
  dec. i. Modified binnding site (cross Resistance (lincosamides, phenicols)
  ii. Permeability
  iii. degrading enzyme
• Inc. N number in the drug>inc. polarization> inc. ion trapping> inc. IC conc. (Azalides: 2N , Triamilides 3N)

Question 2

Macrolides: pharmacokinetics

Answer 2

Lipophilic, not IV (water insoluble), SC,IM only in large animals! does not penetrate BBB, bile exceretion, CYP450 inhibitor

Question 3

Macrolides: side effects

Answer 3

1. Irritant: vomiting and diarrhea (erythromycin can be use to enhance gastric emptying in Ca)
2. tissue irritation
3. Dysbacteriosis: fatal enterocolitis , EXCEPT in foals

Question 4

Macrolides: Drug names

Answer 4

1. Erythromycin: penicillin like spectrum, small animals - campylobacter, resp. infection , diamond skin disease)
2. Spiramycin: 1st choice for oral cavity infection in small animls , not used in large animals.
3. Tylosin: Se dysentry by Lawsonia IC, resp , necrotic entritis (su,ru) SA: ARD (antiobiotics responsive diarrhea)
4. Tylcalosin: PO , su+poul B. hyodysenteriae, L. IC , mycoplasma + fastidious
5. Tilmicosin: Ru+su , toxic for other sp. , respiratory infections
6. Tulathromycin (3N), gamithromycin (2N) , large animals , resp
   5.Tildipirosin: no activity against Mycoplasm
   6.Azithromycin, clarithromycin : hu but used SA, PO, long HL, good for lyme disease m respiratory infections
   7

Question 5

Phenicols: overview

Answer 5

• Very lipophilic, bile +urine excretion , best distribution
• bacteriostatic, S50
• Resistance: Acetyl-transferase(acetyl group addition - ab inactivation)
• Spectrum: broad , pseudomonas is resistant

Question 6

Phenicols: Side effects

Answer 6

1. Anaemia: dose dependent anemia can be caused in any phenicol. (Chloramphenicol eyedrop - ude gloves , can pass through skin)
2. Long term immunosupression : not in vaccinating animals.

Question 7

Phenicols: indications + Drugs

Answer 7

*primary used in food
producting animals: i.FLORFENICOL
1. Respiratory diseases (BRD, SRD)
2.Foot diseases
3. infectious keratoconjuctivitis , FISH aeromonas inf.
*SM: infrequently
eye infection (gloves),Prostatis,Meningitis, MRSP, MRSA infections
ii. Chloramphenicol : NOT in food producing animals (BM supression in Hu)
iii. THiamphenicol

Question 8

Lincosamides: overview

Answer 8

• similar to phenicols
• 50S inhibition, bacteriostatic
• spectrum like macrolides (cross resistance with macrolides and phenicols)
• G positive + anaerobic , NOT fastidious
• 1st choice for bone marrow infectin! (streptococcus osteomyelitis!)
• liver metabolism , bile + urine excresion

Question 9

Lincosamides: Side effects + indications

Answer 9

1. Dysbacteriosis - most toxic antibiotic for intestinal flora (PROHIBITED for monogatric herbivores) - ALWAYS with Probiotics
2. severe tissue irritation (not suitable for UTI)

• NOT for respiratory infections (Fastidious are not sensitive)
• Anaerobic bacteria are very sensitive
• G+

Question 10

Lincosamides: Drug names

Answer 10

1. Lincomycin: (synergy with Spectinomycin = lincospectin) food producing animals, foot rot, mastitis, wounds, metrirtis, proliferative enteropathy
   outstanding against mycoplasma and good against fastidious bacteria
2. Clindamycin: PO, Oral cavity infection , G+ , dermatitis abscess (staph+strep), anal scculitis

Question 11

Pleuromutilins: overview

Answer 11

• Food producing animals ONLY!!!
• similar, 50S , bacteriostatics, cross resistance with macrolides and phenicols
• liver metabolism , CYP450 inhibiton
• bile + urine excetion
• never combine with Ionophore anticoccidials
• Tiamulin, Valnemulin: no dysbacteriosis
• SE: skin erythema, vulvar edema

Question 12

Pleuromutilins: indications and drugs

Answer 12

• G+ , fastidous, B. hyodysenteriae , L. intracellularis , mycoplasma
• indictions: Swine dysentery , proliferative enteropathy , mycoplasmosis , resp(su,poul)
• drugs: Riamulin, vanemulin