Eicosanoid compounds

Prostaglandines, Leukotriens and Thromboxanes.

They are produced in minute amounts by all cells except RBCs and they act locally at the same site of synthesis.
These agents have many physiological processes as mediators and modulators of inflammatory reactions.

BETA-LACTAM ANTIBIOTICS
β-lactam antibiotics are a broad class of antibiotics including penicillin derivatives, cephalosporins, monobactams, carbapenems and β-lactamase inhibitors; basically any antibiotic agent which contains a β-lactam nucleus in its molecular structure. They are the most widely used group of antibiotics available.

Mode of action All β-lactam antibiotics are bactericidal, and act by inhibiting the synthesis of the peptidoglycan layer of bacterial cell walls.β-lactam antibiotics were mainly active only against Gram-positive bacteria, the development of broad-spectrum β-lactam antibiotics active against various Gram-negative organisms has increased the usefulness of the β-lactam antibiotics.

Common β-lactam antibiotics

Penicillins

Narrow spectrum penicillins:  

benzathine penicillin
benzylpenicillin (penicillin G)
phenoxymethylpenicillin (penicillin V)
procaine penicillin

Narrow spectrum penicillinase-resistant penicillins

methicillin
dicloxacillin
flucloxacillin

Moderate spectrum penicillins : 

amoxicillin, ampicillin

Broad spectrum penicillins :      

co-amoxiclav (amoxycillin+clavulanic acid)

Extended Spectrum Penicillins:    

piperacillin
ticarcillin
azlocillin
carbenicillin
 

Cephalosporins

Produced semisynthetically by chemical attachment of side chains to 7-aminocephalosporanic acid. Same mode of action , same resistance mech. 
But tend to be more resistant than penicillins to certain beta –lactamases .

GENERATION BASED ON :
-- BACTERIAL SUSCEPTIBILITY PATTERNS
-- RESISTANCE TO BETA –LACTAMASES
--NOT EFFECTIVE AGAINST -MRSA , L. MONOCYTOGENES , C. DIFFICLE , ENTEROCOCCI

First Generation 

Parentral

- CEPHALOTHIN
- CEFAZOLIN

Oral

- CEPHALEXIN
- CEPHRADINE
- CEFADROXIL

Second Generation

Parentral

CEFUROXIME
CEFOXITIN

Oral

CEFACLOR
CEFUROXIME AXETIL

Third Generation

Parentral

CEFOTAXIME 
CEFTIZOXIME
CEFTRIAXONE 
CEFTAZIDIME
CEFOPERAZONE

Oral 

CEFIXIME 
CEFPODOXIME
CEFDINIR 
CEFTIBUTEN

Fourth Generation

Parentral

CEFEPIME
CEFPIROME

PHARMACOLOGY OF LOCAL ANESTHETICS

 Characteristics

1. Block axon conduction (nerve impulse) when applied locally in appropriate concentrations.

2. Local anesthetic action must be completely reversible; however, the duration of the anesthetic block should be of sufficient length to allow completion of the planned treatment.

3. Produce minimal local toxic effects such as nerve and muscle damage as well as minimal systemic toxic effects of organ systems such as the cardiovascular and central nervous system.

Antidiarrheal

 Antidiarrheal drugs may be given to relieve the symptom (non-specific therapy) or may be given to treat the underlying cause of the symptom (specific therapy). 

Ι. Drugs used for the symptomatic (non-specific) treatment of diarrhoea include: 

• Opiates and opiate derivatives are the most effective (such as morphine), but it is not used because of potentially serious adverse effects. Other agents, such as diphenoxylate and loperamide, are commonly used.

• Adsorbent – demulcent products such as kaolin – pectin preparation may be included in antidiarrheal preparations. Unfortunately, they may adsorb nutrients and other drugs, including the antidiarrheal agents if given concurrently.

• Anticholinergic agents e.g. atropine is occasionally used to decrease abdominal cramping and pain associated with diarrhoea.

ΙΙ. Specific therapy may include the use of antibacterial agents that are recommended for use in carefully selected cases of bacterial enteritis. For example, severe diarrhoea by salmonella, shigella, campylobacter and clostridia species can be treated by antibiotics (ampicillin, chloramphenicol, co-trimoxazole). 

Loperamide

• Similar chemically and pharmacologically to Diphenoxylate.
• Slows gastrointestinal motility by effects on the circular and longitudinal muscles of the intestine.
• Not well absorbed following oral administration.
• Useful in the treatment of diarrhea.