of 46
7/27/2019 pharmacology - antibacterial
1/46
ANTIBACTERIALS
7/27/2019 pharmacology - antibacterial
2/46
ANTIBACTERIAL
Administered in the treatment of bacterialinfections
Act to destroy or suppress the growth of microorganisms
Drugs that are designed to act selectively onforeign organisms that have invaded and
infected the body of a human host
7/27/2019 pharmacology - antibacterial
3/46
ANTIBACTERIAL
ACTION: Interfere with biosynthesis of bacterial cell wall (penicillin) Prevent cells from invading organisms from using
substances essential to their growth and development(sulfonamides, trimethoprin) Interfere with protein synthesis (aminoglycosides,
macrolides)
Interfere with DNA synthesis (fluroquinolones) Alter the permeability of the cell membrane (antifungals,
antiprotozoal)
7/27/2019 pharmacology - antibacterial
4/46
ANTIBACTERIAL SPECTRUM effectiveness of the anti-
infective against invading organisms BACTERICIDAL anti-infective agents that
causes the death of the cells BACTERIOSTATIC anti-infective agents that
interfere with the ability of the cells to
reproduce or divide PROPHYLAXIS use of anti-infective agents to
prevent infection before they occur
7/27/2019 pharmacology - antibacterial
5/46
ANTIBACTERIAL
Classifications: Penicillins Cephalosphorins Aminoglycosides Macrolides Tetracyclines Quinolones Lactams Sulfonamides
7/27/2019 pharmacology - antibacterial
6/46
PENICILLINS
Derived form the cultures of molds ormanufactured semi-synthetically
1st generation natural extracts from severalstrains of Penicillium mold
Natural penicillins potent gram positivekillers ; have little to no coverage against gramnegative organisms
7/27/2019 pharmacology - antibacterial
7/46
PENICILLINS PHARMACODYNAMICS
Bactericidal interfere with cell wall synthesis Most effective on immature cell walls of rapidly
multiplying bacteria PHARMACOHERAPEUTICS
Gram (+) cocci S. pneumoniae Gram (-) cocci N. gonorrheae, N. meningitidis
Gram (+) bacilli B. anthracis, C. tetani, C. diphtheriae, T.pallidum Prophylaxis against subacute bacterial endocarditis, RHD
or CHD undergoing surgery
7/27/2019 pharmacology - antibacterial
8/46
PENICILLINS
CONTRAINDICATIONS Hypersensitivity and allergy
Allergy to penicillin Sx: simple rash to anaphylaxis
Used with caution to: Nursing mothers Neonates Clients with rena, GI, hepatic dysfunctions, bleeding
disorders, MG, and epilepsy
7/27/2019 pharmacology - antibacterial
9/46
PENICILLINS
INTERACTIONS: Probenecid increases serum levels of penicillin by
decreasing renal elimination of the antibiotic May decrease effectiveness of oral contraceptives Increased risk of bleeding when given concurrently
with anticoagulants and thrombolytic agents Tetracyclines, erythromycin and other bacteriostatic
antibiotics may interfere with effectiveness of penicilli Antacids may impair absorption of PO penicillins
7/27/2019 pharmacology - antibacterial
10/46
PENICILLINS
INTERACTIONS Cloxacillin, dicloxacillin, nafcillin, and oxacilin may
be poentiated by PO anticoagulants and anti-inflammatory agents
Increased risk of bleeding when high IV doses of carbeicillin and ticarcillin is given concurrently
with anti-inflammatory agents, NSAIDs, andplatelet aggregation inhibitors Aminoglycosides may be chemically inactivated if
mixed in a solution with penicilin
7/27/2019 pharmacology - antibacterial
11/46
PENICILLINS
INTERACTIONS Chloramphenicol may decrease effetiveness of
penicillin and reduce elimination of chloramphenicol
May have ampicillin-induced rash when given withallopurinol
7/27/2019 pharmacology - antibacterial
12/46
PENICILLINS SIDE/ADVERSE EFFECTS
GI: diarrhea, N/V, flatulence, abnormal taste,epigastric distress, sore mouth and tongue, dark
discoloration of tongue, oral thrush RENAL: glomerulonephritis HEMA: bone marrow depression, decreased blood
cell counts CNS: neuromascular irritability, lethargy, anxiety
depression, agitation, confusion, hallucinations RESPI: wheezes, laryngospasm, laryngeal edema
7/27/2019 pharmacology - antibacterial
13/46
PENICILLINS
NURSING RESPONSIBILITY History taking
Prior hypersensitivity to penicillins Other conditions: bleeding disorders, GI disease, renal
impairment Given on an empty stomach ( 1 hr before or 2
hours after meals) except for amoxicillin, penicillinV, augmentin
Obesrve for electrolyte imbalance
7/27/2019 pharmacology - antibacterial
14/46
7/27/2019 pharmacology - antibacterial
15/46
PENICILLINS
PENICILLIN G Nursing responsibility
IM or IV Dosage vary according to severity of infections Dosages >10 M u/day must be given via IV infusion Deep IM injections to large muscles Monitor for signs of hyperkalemia and hypernatremia Used with caution to clients with renal insufficiency
7/27/2019 pharmacology - antibacterial
16/46
7/27/2019 pharmacology - antibacterial
17/46
PENICILLINS
Penicillin V Peak: 30 60 minutes Half life: 1 hour Protein binding: 80 90% Excretion: tubular secretion in the kidney
7/27/2019 pharmacology - antibacterial
18/46
PENICILLINS
Ampicillin Pregnancy category B Effective against spectrum of both gram (+) and
gram (-) organisms Stable in gastric acid Used in RTI, soft tissue infections, otitis media,
septicemia, bacterial meningitis, gonococcalinfections, PID, prevention of bacterialendocarditis
7/27/2019 pharmacology - antibacterial
19/46
PENICILLINS
Ampicillin Peak (PO): 1.5 2 hrs; (IM): 1 hour Half life: 1 1.5 hours Protein binding: 20 -25% Nursing responsibility:
Given on an empty stomach Stable in saline for 24hrs and in D5W for 2hrs, IV
preparation should be given over 15-30mins
7/27/2019 pharmacology - antibacterial
20/46
PENICILLINS
Amoxicillin Pregnancy category B Acid-stable penicillin with a spectrum similar to
ampicillin but is better absorbed from the GIT Less effective to Shigella than ampicillin Used againts infections of ENT, lower RT due to
streptococci, pneumococci; GU infections causedby E. coli; skin and soft tissue infections
7/27/2019 pharmacology - antibacterial
21/46
PENICILLINS
Amoxicillin Peak: 2 hours Protein binding: 20 25% Half life: 1 1.3 hours Nursing reponsibility
Available only in PO form Usually given Q8hrs (TID) Available in combination with potassium clavulanate
7/27/2019 pharmacology - antibacterial
22/46
PENICILLINS
Methicillin Pregnancy category B Semisynthetic salt of penicillin that is active against
penicillinase-producing strains of staphylococci Peak: 0.5 to 1hr Half life: 0.4 to 0.8 hour
Protein binding: 40 -50% Given IV or IM Excretion: hepatic, bile, real routes
7/27/2019 pharmacology - antibacterial
23/46
7/27/2019 pharmacology - antibacterial
24/46
CEPHALOSPORIN
1st Generation Indications:
Respiratory tract infections Otitis media Skin infections Bone infections Genitourinary tract infcetions
7/27/2019 pharmacology - antibacterial
25/46
CEPHALOSPORIN
1st Generation Cefazolin Cefadroxil Cephalexin
7/27/2019 pharmacology - antibacterial
26/46
7/27/2019 pharmacology - antibacterial
27/46
CEPHALOSPORIN
2nd Generation Cefamandole Cefuroxime Cefoxitin Cefotetan Cefonicid Cefmetazol
7/27/2019 pharmacology - antibacterial
28/46
CEPHALOSPORIN
3 rd Generation Treatment of previously mentioned infections,
also enhance the spectrum of coverage for
additional gram negative infections Prophylaxis for perioperative infection
4 th Generation
7/27/2019 pharmacology - antibacterial
29/46
CEPHALOSPORIN
3 rd Generation Ceftizoxine Cefoperazone Cefprozil Cefotaxime Ceftazidime Cetriaxone Cefixime
7/27/2019 pharmacology - antibacterial
30/46
CEPHALOSPORIN
Pharmacokinetics Absorbed rapidly in the GIT May be given w/o regard to meals but presence of
food will delay the absorption Peak levels:
1hr PO
45mins IM; 15mins IV Maximum concentrations occur in liver and
kidneys; excretion kidneys
7/27/2019 pharmacology - antibacterial
31/46
CEPHALOSPORIN
Contraindications/Cautions Use cautiously in patients with penicillin allergy Use cautiously in patients with GI or renal disease
especially those receiving diuretics Drug-drug interactions
Alcohol: antabuse-like effect Aminoglycosides: increased risk of nephrotoxicity Aspirin: increased potential risk of bleeding Anticoagulants: increased anticoagulant effect
7/27/2019 pharmacology - antibacterial
32/46
AMINOGLYCOSIDES
Particularly useful against gram (-) pathogens Used for treatment of sepsis, endocarditis,
bacteremia Ineffective against anaerobes Work poorly under conditions of low oxygen
tension and in acid environments BACTERICIDAL inhibit protein synthesis
7/27/2019 pharmacology - antibacterial
33/46
AMINOGLYCOSIDES
Indications: Gram (-) enteric bacilli Tuberculosis Sepsis or bacteremia Strongly indicated in combination with other
antibiotics for aerobic infections Given in combination with penicillin to encourage
facilitation of the aminoglycosides into the cell
7/27/2019 pharmacology - antibacterial
34/46
AMINOGLYCOSIDES
Pharmacokinetics: Poor GI absorption Half life is 1-4hrs Excretion: kidneys
Contraindications/Cautions: Preexisting renal disease Neuromuscular disease Patients taking skeletal muscle relaxants
7/27/2019 pharmacology - antibacterial
35/46
AMINOGLYCOSIDES
Drug interactions Amphotericin B, cisplatin, cyclosporine,
vancomycin, enflurane, cephalosporin,
methoxyflurane increased nephrotoxicity Loop diuretics increased ototoxicity Increase effect of neuromuscular blocking agents
Synergistic effect when given with penicillinagainst pseudomonas
Decreases absorption of dogoxin
7/27/2019 pharmacology - antibacterial
36/46
AMINOGLYCOSIDES
Streptomycin Amikacin Gentamycin (Garamycin) Tobramycin Neomycin
Kanamycin
7/27/2019 pharmacology - antibacterial
37/46
MACROLIDES
BACTERIOSTATIC inhibit the growth of microorganism
Inhibit protein synthesis Indications:
Infections caused by gram (+) bacteria Indicated for acute diphthria Penicillin-sensitive/allergic clients Prophylactic treatment of ophthalmia
neonatorum
7/27/2019 pharmacology - antibacterial
38/46
MACROLIDES
Indications Erythromycin drug of choice for legionnaires
disease, whooping cough Intestinal amoebiasis, upper and lower RTI
Treatment of H. influenza when used withsulfonamide
Uncomplicated urethral, endocervical, rectalinfections Syphilis caused by T. pallidum
7/27/2019 pharmacology - antibacterial
39/46
MACROLIDES
Pharmacokinetics PO: good absorption, should be given on empty
stomach, peak: 1-4hrs, duration: 6hrs Excreted mostly in bile
Contraindications/cautions Liver disease Pregnant or breatfeeding
7/27/2019 pharmacology - antibacterial
40/46
MACROLIDES
Drug interactions Carbamazepine, cyclosporine, digoxin, ergotamine,
terfenadine, triazolam, warfarin may increase serumlevels
Chloramphenicol, clindamycin, lincomycin decreasedeffects of these drugs
Common Macrolides
Erythromycin Clarithromycin azithromycin
7/27/2019 pharmacology - antibacterial
41/46
TETRACYCLINES
BACTERIOSTATIC Inhibit protein synthesis Indications
Ricketssiae, C. trachomatis V. cholerae, H. ducreyi DOXYCLINE
T. pallidum hypersensitive to penicillin Adjunct therapy fro intestinal ameobiasis
Uncomplicated gonococcal infections
7/27/2019 pharmacology - antibacterial
42/46
TETRACYCLINES
Pharmacokinetics Action
Short acting: tetracycline Intermediate: methacycline Long acting: doxycycline
Concentrated in bile, excreted in kidneys Drug interactions
Do not use during tooth development Lactation Renal disease
7/27/2019 pharmacology - antibacterial
43/46
TETRACYCLINES
Contraindications: Do not use during tooth development Avoid use in lactation
Pts with renal failure: minocycline and doxycycline Drug interaction:
Oral contraceptives: decrease effectiveness of contraceptives
Oral anticoagulants: increase effect of these agents Cimetidine: decrease GI absorption of tetracycline Digoxin: increase effect of digoxin
7/27/2019 pharmacology - antibacterial
44/46
TETRACYCLINES
Adverse/Side Effects Photosensitivity, manifested by an exaggerated
sunburn Common Tetracyclines
Doxycycline Minocycline
7/27/2019 pharmacology - antibacterial
45/46
QUINOLONES Broad spectrum synthetic antibiotic class with
both gram (+) and gram (-) At by interference with DNA replication BACTERICIDAL Indications:
Uncomplicated gonorrhea Respiratory, soft tissue, and skin infections, STD
caused by gonorrhea and chlamydia Prophylaxis: Transurethral surgery
7/27/2019 pharmacology - antibacterial
46/46
QUINOLONES Drug interactions
Theophylline: elevated levels Antacids: decreased intestinal absorption Food: intake of 1-2 hours of administration will interfere
absorption Common Quinolones
Ciprofloxacin Ofloxacin Norfloxacin Nalidixic acid Lomefloxacin