SEMINAR ON
ANTIBIOTICS
PRESENTED BY Dr. AMIT BYATNAL (POST GRADUATE STUDENT)
DEPT. OF ORAL MEDICINE AND RADEIOLOGY, SIBAR INSTITUTE OF DENTAL SCIENCES, TAKKELLAPADU, GUNTUR.
CERTIFICATE This is to certify that the Seminar entitled, “ANTIBIOTICS” being submitted by Dr. Amit Byatnal, under the guidance and supervision and completed to our full satisfaction.
SIGNATURE OF HEAD OF THE DEPARTMENT
CONTENTS Introduction. History of Antibiotics Classification of antimicrobial drugs Problems with AMA Choice of AMA Principles of administration Indications for antimicrobial agents used in dentistry Beta lactam antibiotics Quinolones Tetracyclines Macrolides Nitroimidazoles Antifungal drugs Conclusion References
• INTRODUCTION • Antimicrobial agents: Substances that will suppress the growth/ multiplication of bacteria and prevent their action.
• Antibiotic agents: Chemical substances produced by microorganisms that have the capacity, in dilute solutions, to produce antimicrobial action.
HISTORYOF ANTIBIOTICS • 1877 Louis Pasteur Inhibition of some microbes by others; anthrax (Bacillus anthracis) • 1908 Gelmo Synthesized sulfanilamide (1st sulfonamide • 1928 Fleming… • Penicillin notatum inhibits growth • ‘PENICILLINS’ • 1941 Chain n Florey • Discovered properties of penicillin • 1932 Domagk Prontosil • Therapeutic value sulfonamides • 1943, Selman Waksman isolated, Streptomyces griseus …Streptomycin
• Classification
Chemical structure: • Sulfonamides and related drugs. • Sulfadiazine and others. • Sulfones – Dapsone (DDS), Paraaminosalicylic acid (PAS). • Diaminopyrimidines • Trimethoprim • Pyrimethamine • Quinolones • Nalidixic acid • Norfloxacin • Ciprofloxacin etc
• β-lactam antibiotics • Penicillins • Cephalosporins • Monobactams • Carbapenems • Tetracyclines
• Oxytetracycline • Doxycycline etc • Nitrobenzene derivative • Chloramphenicol
• Aminoglycosides • Streptomycin • Gentamicin • Neomycin etc • Macrolide antibiotics • Erythromycin • Roxithromycin • Azithromycin etc • Polypeptide antibiotics • Polymyxin-B • Colistin • Bacitracin • Tyrothricin
• Glycopeptides • Vancomycin • Teicoplanin • Oxazolidinone
• Linezolid • Nitrofuran derivatives • Nitrofurantoin • Furazolidone • Nitroimidozoles • Metronidozole • Tinidazole
• Nicotinic acid derivatives • Isoniazid • Pyrazinamide • Ethionamide • Polyene antibiotics • Nystatin • Amphotericin-B • Hamycin • Azole derivatives • Miconazole • Clotrimazole • Ketoconazole • Fluconazole
• Others
• Rifampin • Lincomycin • Clindamycin • Spectinomycin • Sod. fusidate • Cycloserine • Viomycin • Ethambutol • Thiacetazone • Clofazimine • Griseofulvin
• Type of organisms against which primarily active • Antibacterial • Penicillins • Aminoglycosides • Erythromycin etc • Antifungal • Griseofulvin • Amphotericin B • Ketoconazole • Antiviral • Idoxuridine • Acyclovir
• Amantadine • Zidovudine etc
• Antiprotozoal • Chloroquine • Pyrimethamine • Metronidazole • Diloxanide etc • Anthelmintic • Mebendazole • Pyrantel • Niclosamide • Diethyl carbamazine etc
• Bactericidal • Aminoglycosides • Bacitracin • Cephalosporins • Metronidiazole • Vancomycin • Penicillins • Ciprofloxacin
• Streptomycin • Cotrimoxazole • Bacteriostatic • Chloramphenicol • Clindamycin • Erythromycin • Sulfonamides • Tetracycline • Trimethoprim
Spectrum of activity • Narrow spectrum • Broad spectrum
Mechanism of action • Problems with use of AMA • Toxicity • Local irritancy: • -Systemic toxicity: • -Therapeutic index- high, low, very low • Hypersensitivity reactions : • Drug resistance -
Natural- lack of metabolic process or target site
-
Acquired – due to use over a period of time, mutations or gene transfer
• Preventing Resistance to Drugs • Limit the use of antimicrobial agents to the treatment of specific pathogens sensitive to the drug being used • Notorious-Make sure doses are high enough, and the duration of drug therapy long enough , combination therapy • Be cautious about the indiscriminate, inadequate or unduly prolonged use of anti-infectives
• Superinfection • Nutritional deficiencies • Masking of an infection • Choice of AMA agent- patient factors • 1.Age : affect kinetics of drug. • Conjugation and excretion of chloremphenicol- gray baby syndrome • Sulfonamides displace bilirubin from PBS- kernicterus • Tetracycline accumulates in bone and teeth • 2. Renal and hepatic failure: cautious use and dose reduction • 3. Local factors: • presence of pus and secretions- AMAs, surgical drainage reduces causative bacteria and suppresses anaerobic bacteria • Presence of necrotic material and infection
• Hematomas – foster growth • 4.Drug allergy • 5.Impaired host defense • 6.Pregnancy • 7.Genetic factors • Organism related considerations • Drug factors • Spectrum of activity • Type of activity • Sensitivity of the organism • Relative toxicity • Pharmacokinetic profile • Route of administation • Evidence of clinical efficacy • Cost • Microorganisms isolated from pulpal/periapical infections • Aerobic • Gram +ve cocci • Staphylococci • Gram +ve Baccili • Lactobaccili • Corynebacterium
• Eikenella corrodens
• Anaerobic • Gram +ve cocci • Peptostreptococcus • Gram –ve cocci • Veillonella • Gram +ve baccilli • Actinomyces • Eubacterium • Clostridia • Propionibacterium
• Gram -ve baccilli • Bacteriodes • Fusobacteria • Porphyromonas • Prevotella • Treponemas • Treponema denticola
• Treponema macrodentium • Treponema oralis • Treponema vincenti • PRINCIPLES OF ANTIBIOTIC THERAPY • PRINCIPLE 1: TO DETERMINE THE SEVERITY OF INFECTION • PRINCIPLE 2: TO EVALUATE STATE OF PATIENT’S HOST DEFENSE MECHANISMS • PRINCIPLE 3: TO TREAT INFECTION SURGICALLY • PRINCIPLE 4: TO SUPPORT THE PATIENT MEDICALLY • PRINCIPLE 5: CHOOSE AND PRESCRIBE APPROPRIATE ANTIBIOTIC • PRINCIPLE 6: PROPER ANTIBIOTIC ADMINISTRATION
• PRINCIPLES OF ANTIBIOTIC ADMINISTRATION • Proper dose :
• DRUG DOSAGE -
‘Dose’ is the appropriate amount of a drug needed to produce a certain degree of response in a patient.
• Body size : -
Individual dose = BW(kg)/70 x average adult dose
-
Individual dose = BSA(m2
) /1.7x average adult dose
• NEONATES AND INFANTS • Greater percentage of body weight compared with body water • Greater volume of distribution • Increased serum half lives • Reduced gastric emptying • Reduced plasma protein binding • Reduced GFR
• 2) Proper time interval : • 3) Proper route of administration : • Parenteral administration will produce the necessary serum level of antibiotics. • Oral route results in the most variable absorption. • For maximum absorption is taken in fasting stage. • 4) Consistency in regard to route of administration : • When treating a serious, established infections, parenteral antibiotic therapy is frequently the method of choice. • Combination antibiotic therapy : • The rationale for the use of 2 or more drugs together is to minimize • the emergence of antibiotic resistant microorganisms
• to increase the certainty of a successful clinical outcome • to treat mixed bacterial infections • to prevent superinfection • to treat severe infections of unknown etiology • to decrease toxicity without decreasing efficacy
-
Examples :
• Isoniazid + ethambutol + streptomycin in treatment of tuberculosis. • Rules : • 2 bactericidal drugs produce, supraadditive effects, not antagonism. (1+1>2) • The combination of a bacteriostatic and a bactericidal drug generally results in diminished effects. (1+1<2) • 2 bacteriostatic drugs are never inhibitory. (1+1=2)
• Results : • Indifference when the effect is equal to the single most active drug or equal to the arithmetic sum of the two, use is not justified. • Antagonism : when the combined drug effect is less than the algebraic sum of the effects on the individual drugs in the mixture. • Synergism : ability of two antibiotics acting together to markedly increases the rate of bactericidal action compared to either drug alone. • Disadvantages : • Adds nothing to therapeutic efficacy and may even reduce it (antagonism).
• Increase antibiotic toxicity and allergy. • Increase the likelihood of superinfection • Discourages specific etiologic diagnosis and promote false security. • Encourage inadequate doses, particularly with fixed dose combination therapy. • Increased cost • Emergence of resistant bacterial strains • Increase the environmental spread of antibiotic resistant bacteria. • FACTORS INFLUENCING ANTIBIOTIC THERAPY • Minimal Inhibitory Concentration • Concentration-dependent Vs Time-dependent antibiotics • Post-antibiotic effects • MINIMAL INHIBITORY CONCENTRATION • Is the lowest antibiotic concentration that prevents growth of microorganism after an incubation period of 18 – 24 hours with a standard inoculum of 104 to 105 cu/ml • MINIMAL BACTERICIDAL CONCENTRATION • Is the lowest concentration of drug that causes the complete destruction of the organisms or permits survival of less than 0.1% of the inoculum • RULE OF THUMB • The concentration of the antibiotic in the blood should exceed the MIC by a factor of 2-8 times to offset the tissue barriers that restrict access to the infected site
• CONCENTRATION DEPENDENT Vs TIME DEPENDENT ANTIBIOTICS • Aminoglycosides, metronidazole,
fluoroquinolones
Concentration dependent • Bactericidal activity depends on the • drug concentration • Beta-lactams and vancomycin • Long time of exposure of the organisms • Better the bactericidal activity
• POSTANTIBIOTIC EFFECTS • Is the persistent supression of microbial growth after short time exposure to an antimicrobial agent. • MECHANISM : Is the time necessary to recover from sublethal structural and metabolic alterations that prevents resumption of bacterial regrowth.
• Indications for antimicrobial agents in dentistry • Therapeutic indications • Prophylactic indications • Dental procedure for which antibiotic prophylaxis is recommended to prevent infective endocardititis • (AHA recommendation) • Dental extractions • Periodontal procedures • Replantation procedure • Implant placement • Initial placement of orthodontic bands • Intra ligamentary local anesthetic injection • Incision and drainage • Not recommended : 1.Restorative dentistry 2.LA injections 3.Intracanal endodontic treatment 4.Post-op suture removal 5.Oral radiographs
• CLASSIFICATION OF PENICILLIN • Natural penicillins :
• Penicillin G (Benzyl penicillin) • Acid resistant penicillins : • Phenoxymethyl penicillin (penicillin V) • Penicillinase – resistant penicillins : • Acid labile : Methicillin, naficillin, cloxacillin, dicloxacillin • Extended spectrum penicillins : • Carboxypenicillins : Carbenicillin, ticarcillin • Aminopenicillins : Ampicillin, amoxicillin • Ureidopenicillins • BENZYL PENICILLIN (PENCILLIN G) • Antibacterial activity • Inhibits the growth of susceptible organism. • Mainly gram +ve, gram –ve cocci and some gram +ve bacilli with exception of enterococci. • Cocci – Highly sensitive – Streptococci, Pneumococci, Staph. aureus, N. gonorrhoeae, N. meningitis • Bacilli – B. anthracis, Corynebacterium diphtheriae, clostridium tetany and spirochetes • Actinomyces israelii is moderately sensitive
• Preparation and dose :
• PnG inj 0.5-5 MU i.m or i.v 6-12 hours • Procaine pencillin inj 0.5, 1 MU dry powder in vial • ADVERSE REACTIONS : • Miscellaneous reactions : • Nausea and vomiting on oral PnG • Sterile inflammatory reaction at the site of IM inj. • Prolonged IV administration may cause thrombophlebitis • Accidental IV administration of procaine PP cause anxiety, mental disturbances paraesthesia and convulsions
• Intolerance : • Major problem with PnG includes idiosyncratic, anaphylactic and allergic reactions • Other allergic reactions are • Skin rashes • Serum sickness • Renal disturbance • Hemolytic disturbance • Anaphylaxis • Jarisch herxheimer reaction • Super infection • Hyperkalemia
• Uses : • PnG is the drug of choice for infections • Streptococcal infections • Pneumococcal infections • Meningococcal infections • Gonorrhoea • Syphilis • Diphtheria • Tetanus and gas gangrene • Prophylactic uses
• The major drawbacks of benzyl penicillin are • Inactivation by the gastric hydrochloric acid • Short duration of action • Poor penetration into CSF • Activity mainly against gram +ve organism • Possibility of anaphylaxis • Acid resistant pencillins : • 1. Potassium phenoxymethyl penicillin (penicillin V) • Dose : infants 60 mg, children 125-250 mg given 6 hourly • CRYSTAPEN-V, KAYPEN, PENIVORAL 65, 130, 125, 250 mg tablets 125 mg/5 ml dry ser
• II) Pencillinase resistant pencillins : • Methicillin • Effective in staphylococci • It is given IM or IV (slow) in the dose of 1 gm every 4-6 hours. • Haematuria, albuminuria and reversible interstitial nephritis are the special adverse effect of methicillin. • Cloxacillin • Weaker antibacterial activity. • Distrubuted throught out the body, but highest concentration in kidney and liver. 30% excreted in urine. • Oral dose for adults 2-4 gm divided into 4 portions children 50100mg/kg/day. • IM adults 2-12 gm/day, children 100-300 mg/kg/day every 4-6 hours. • BIOCLOX, KLOX, CLOCILIN 0.25, 0.5 gm cap, 0.5 gm/vial.
• III) Extended spectrum pencillins : • Amino pencillins -
Ampicillin –
• Antibacterial activity is similar to that of PnG that is more effective than PnG against a variety of gram-ve bacteria • Drug is effective against H.influenzae strep.viridans, N.gonorrhea, Salmonella, shigellae, Klebsilla and enterococci. -
Absorption, fate and excretion :
• Oral absorption is incomplete but adequate • Food interferes with absorption • Partly excreted in bile and partly by kidney
• Dose : 0.5-2 gm oral/IM or IV depending on severity of infection every 6 hours -
Children : 25-50 mg/kg/day
-
AMPILIN, ROSCILLIAN, BIOCILIN – 250, 500 mg cap 100mg/ml ped drops, 250 mg/ml dry syr, 1 gm/vial inj.
• USES : • Urinary tract infections • Respiratory tract infections • Meningitis • Gonorrhoea • Bacillary dysentry • Septicaemias • SABE
• Adverse effects : • Diarrhoea is frequent • Skin rashes is more common • Unabsorbed drug irritates lower intestines • Patient with history of hypersensitivity to PnG should not be given
ampicillin.
• AMOXICILLIN : • This is a semisynthetic penicillin. • (amino-p-hydroxy-benzylpenicillin) • Antibacterial spectrum is similar to ampicillin. • Oral absorption is better; food does not interfere; higher and more sustained blood levels are produced. • It is less protein bond and urinary excretion is higher than that of ampicillin. • Incidence of diarrhoea is less • Dose : 0.25-1 g TDS oral; • AMOXYLIN, NOVAMOX, SYNAMOX, MOX, AMOXIL 250, 500 mg cap, 125 mg/5ml dry syr, 500 mg/vial inj. • USES : • Oro-dental infections • Upper RTI • Bronchitis • Urinary infection • SBE • Gonorrhoea
• BETA LACTAMASE INHIBITORS
• CLAVULANIC ACID • Obtained from STREPTOMYCES CLAVULIGERUS • Betalactam ring – no antibacterial activity • Suicide inhibitor –inactivated after binding to enzyme • Permeates the outer layers of cell wall of gram-ve bacteria
• Adverse effects : • Pain-thrombophebitis • Rashes and diarrhoea • Uses : • Mixed aerobic-anaerobic infections • Dental infections caused by beta lactamase producing bacteria • Gonorrhoea • Skin/soft tissue infections • SULBACTAM • CEPHALOSPORINS • Cephalosporium acremonium was the first source. • They contain 7 amino cephalosporonic acid nucleus. • Structurally they contain betalactam and dihydro thiazine rings. • Mechanism of action : •
Act by inhibiting bacterial cell was synthesis and are bactericidal.
• Classification • Classified according to its antibacterial activity. • First generation cephalosporin • Good activity against gram +ve bacteria. (except enterococci). • Most oral cavity anaerobes are sensitive. • Parental
Oral
• CEPHALOTHIN
CEPHALEXIN
• CEFAZOLIN
CEPHRADINE CEFADROXIL
• Cephalaxin and Cephadroxil : • Useful in treating community acquired, respiratory and urinary tract infections and in surgical prophylaxis. • Infections of head and neck region. • Dose: Oral 0.25 - 1g 6-8 hrly • Children : 25-100mg/kg/day • IM – 0.25g 8 hrly (mild cases) 1g 6 hrly (severe cases). • Drops – cephaxin 125mg/5ml syrup. • 100mg /ml ped. drops. • SPORIDEX, CEPHAXIN, CEPHACILLIN, CEFADROX, DROXYL
• Second generation cephalosporins :
• Increased activity against gram –ve organism. • More active against anaerobes. -
Parenteral
Oral
• CEFUROXIME
CEFACLOR
• CEFOXITIN
CEFUROXIME AXETIL
• More active against H. influenzae, E coli. • Dose : 250mg, 125mg, 125mg/5ml syr. and • 50 mg /ml ped. drops. • KEFLOR, CEFTUM, CEFOGEN, FUROXIL. • Third Generation Cephalosporins • High activity against gram –ve entrobacteriaceae, some inhibit Pseudomonas as well. • Parenteral
Oral
Cefataxime
Cefixime
Ceftizoxime
Cefpodoxime proxetil
Ceftriaxone
Cefdinir
Ceftazidime
Ceftibuten
Cefoperazone • Dose: 250mg, 500mg, 1000mg per vial inj • CLAFORAN, CEFIZOX,MONOCEF,CEFAZID.
• Fourth Generation Cephalosporins • Similar to 3rd generation ,but is highly resistant to
beta- lactamases.
Due to high potency and extended spectrum, it is effective in many serious
infections like hospital acquired pneumonia, bacteremia, septicaemia. • Parentral Cefepime Cefpirome • Dose: 1-2 g i.m/i.v 12hrly • CEFROM, CEFROTH, KEFAGE • Adverse reactions : • Local reactions – cause pain (IM) and cause thrombophlebitis (IV) • Allergy – skin rashes • Nephrotoxicity • Bleeding disorders • Intolerance to alcohol
• Uses : • Alternatives to penicillins. • RTI, UTI and soft tissue infection • Penicillinase producing staph infection. • Septicaemias. • Surgical prophylaxis • Meningitis, gonorrhoea • Typhoid • Mixed aerobic and anaerobic infections • Infection by odd organism or hospital infections
• Prophylactic treatment in neutropenic patients. • Dental infections • Alternative to pencillins- hypersensitivity and resistance • Oral – 1st and 2nd generation • Sulfonamides • Short acting(4-8hr)- Sulfadiazine •
Intermediate acting (8-12hr)- Sulfamethoxazole, Sulfamoxole
• Long acting(7 days)- Sulfadoxine, Sulfamethopyrazine • Special purpose Sulfonamides – Sulfacetamide sod, Sulfasalazine, Mafenide, Silver sulfadiazine • Mechanism of action • In bacteria, antibacterial sulfonamides act as competitive inhibitors of the enzyme dihydropteroate synthetase, DHPS. DHPS catalyses the conversion of PABA (para-aminobenzoate) to dihydropteroate, a key step in folate synthesis. Folate is necessary for the cell to synthesize nucleic acids (nucleic acids are essential building blocks of DNA and RNA), and in its absence cells will be unable to divide. Hence the sulfonamide antibacterials exhibit a bacteriostatic rather than bactericidal effect.
• Side effects • Sulfonamides have the potential to cause a variety of untoward reactions, including urinary tract disorders, haemopoietic disorders, porphyria and
hypersensitivity reactions. When used in large dose, it may develop a strong allergic reaction. One of the most serious is Stevens Johnson syndrome(or toxic epidermal necrolysis). • QUINOLONES • Entirely synthetic antimicrobials are active primarily against gram –ve bacteria. • Nalidixic acid- low potency, modest blood and tissue levels, limited spectrum, high resistance • Fluoroquinolones – high potency, expanded spectrum, better tissue penetrance, slow resistance.
• CIPROFLOXACIN •
First generation FQ active against a broad range of bacteria especially gram –ve aerobic bacilli.
• Microbiological features : • Rapid bactericidal activity and high potency. • Relatively long post antibiotic effect • Low frequency of mutational resistance. • Protective intestinal streptococci and anaerobes are spared.
• Less active at acidic pH.
• Adverse effect : • GIT – Nausea, vomiting, bad taste, anorexia, diarrhoea is infrequent. • CNS- Dizziness, headache, restlessness, anxiety, insomnia and seizures are rare. • Skin/hypersensitivity – rashes, pruritis, urticaria. • Tendonitis and tendon rupture • Uses : • Broad range of infections • Minor cases, orodental -not indicated • UTI • Bacterial gastroenteritis • Prophylaxis -Typhoid • Bone, soft tissue, wound infection. • Combinations- gram –ve septicaemias • Tuberculosis • CIFRAN, CIPLOX, CIPROBID, CIPROLET • 250, 500,750 mg tab, 200mg/100 ml IV infusion 3mg/ml eye drops.
• Norfloxacin -
Less potent than Ciprofloxacin.
-
Used for Pseudomonas, Urinary and genital tract infections.
• NORFLOX -200,400mg • Ofloxacin -
Activity against gram –ve bacteria
-
Chlamydia and Mycoplasma
-
Alternative drug for Tuberculosis
-
Used mainly for Gonorrhea
• ZANOCIN -200,400mg • Levofloxacin -
Sinusitis, Pylonephritis, soft tissue infections.
• LOMEF- 400mg • Gatifloxacin -
Excellent activity against Streptococci pneumoniae
-
Indicated in community acquired pneumonia, exacerbation of chronic bronchitis, and other respiratory tract infections.
-
Used in urinary tract infectons and gonorrhhoea.
• GATIQIN – 200,400 mg tab
• Sparfloxacin -Enhanced activity against gram –ve bacteria, Bacteroides fragilis, anaerobes and mycobacteria. -
Indicated in Pneumonias, chronic bronchitis, sinusitis and other ENT
infections. -
Good efficacy in Mycobacterium avium infection in AIDS patients and Leprosy.
-
Higher incidence of phototoxic reactions.
• SPARTA, SPARDAC -100,200 mg tab • NITROIMIDAZOLES • METRONIDAZOLE : • Introduced in 1959 • Broad spectrum- e.histolytica, giardia lamblia • Anaerobic infections- chance discovery • Tinidazole, secnidazole, ornidazole, satranidazole • Cidal activity against protozoa and anaerobic bacteria such as B fragilis, Fusobacterium, h.pyroli, spirochetes • Metronidazole is selectively toxic to anaerobic microorganisms. • Pharmacokinetics : • Completely absorbed from the small intestine. • Widely distributed in the body • It is metabolized in liver • Excreted in urine. 8hr
• Adverse effects :
• Anorexia, nausea, metallic taste and abdominal cramps • Looseness of stool is occasional, • Headache, glossitis, dryness of mouth, dizziness, rashes and transient neutropenia. • Prolonged administration may cause peripheral neuropathy and CNS effects • Thrombophlebitis
• Contraindications : • In neurological disease, blood dyscrasias, chronic alcoholism • First trimister of pregnancy
• Ornidazole • Activity similar to Metronidazole but it is slowly metabolised . • Used in anaerobic infections, Amoebiasis, Giardiasis, Trichomonasis, and bacterial vaginosis. • DAZOLIC -500mg tab, 500mg/100ml vial for i.v. infusion. • Uses- Orodental infections • MZ 200-400mg TDS(15-30mg/kg/day) – anaerobes not inhibited by pencillin • ANUG- MZ+Amox - 5days • Periodontitis, pericoronitis, acute apical infections, endodontic infections- 57 days • Aerobic and facultative bacteria- MZ+pencillin/cephalosporin/macrolides
• FLAGYL, METROGYL, METRON, ALDEZOLE 200, 400 mg tab, 200 mg/5ml susp. • TINIDAZOLE • It is an equally efficacious congener of metronidazole • Metabolism is slower and duration of action is longer • Incidence of side effects is lower-Metallic taste, nausea, rashes • TINIBA, TRIDAZOLE, 300, 500, 1000 mg tab, 800 mg/400 ml iv • Dental infections: 0.5g(10mg/kg) BD for 5 days • 2g orally followed 0.5g BD for 5days • 800mg iv until oral therapy
• TETRACYCLINES
• Napthacene derivatives made up by fusion of 4 partially unsaturated cyclohexane radicals • Tetracyclines are bacteriostatic. • Classification • Antimicrobial activity : • Gram+ve and –ve cocci are sensitive-R • Gram+ve bacilli are inhibited
• Entero bacteriaceae are highly resistant • Spirochetes are quite sensitive • All rickettsiae and chlamydiae are highly sensitive
• Mechanism of action • Tetracycline antibiotics inhibit protein synthesis by inhibiting the binding of aminoacyl-tRNA to the mRNA-ribosome complex. They do so mainly by binding to the 30S ribosomal subunit in the mRNA translation complex.[
• Tetracyclines are widely used in treatment of periodontal diseases. • Used in the treatment of Localised aggressive periodontitis.
• Adverse effects : • GIT-epigastric burning, nausea, vomiting, diarrhea • Liver damage • Renal failure • Phototoxicity • Effects on teeth & bones- Ca tetracycline chelate • Hypersensitivity Reactions • Superinfection; Antianabolic effect
• DOSE • Tetracycline – 1-2g per day in adults •
Children over 8yrs -25 to 50mg /kg daily in 2 to4 divided dose
• TERRAMYCIN,RESTECLIN-250,500mgcap,50mg/ml in10ml vial inj • Ledermycin 150,300mg cap/tab • DOXT, NOVADOX, TETRADOX-100mg cap. • Cyanomycin 50,100 mg cap • Precaution : • Not to be used in pregnancy, lactation and in children • Avoided in patients on diuretics • Used cautiously in renal and hepatic insufficiency • Beyond expiry date should not be used • Do not mix injectable Tc with Pn- inactivation occurs • Local Drug Delivery Systems • Subgingival Doxycycline •
-FDA approved 10% of Doxycycline in gel system using a syringe Atridox.
• Reduction in oral microbes. No overgrowth of foreign pathogens. • Subgingival Minocycline
• -Sustained release form of Minocycline microspheres(Arestin) for subgingival placement as an adjuvant to scaling and root planing. • -2% Encapsulated into bioresorbable microspheres is used. • ORODENTAL CONDITIONS • Limited use- acute dental infections • Periodontal diseases – collagenase • Refractory periodontal disease – 2week tetracycline(1g/day) or doxycycline(0.1-0.2g/day) • Juvenile periodontitis – 2-4 week
• MACROLIDES • Macrocyclic lactone ring with attached sugars •
ERYTHROMYCIN-Streptomyces erythreus
• Alternative to pencillin • Water solubility is limited-stable in cold • Antibacterial activity : static- cidal • Narrow spectrum antibiotic •
against penicillin resistant staphylococci
• Active against more gram+ve • Mechanism of action :
• Dose :
• Adults 250 - 500mg 6hrly • Children 30 – 60mg/kg/day • Erythromycin (base) - ERYSAFE 250 mg tab • Erythromycin stearate -ERYTHROCIN – 250,500mg tab • 100mg/5ml susp;100mg/ml ped drops •
E estolate- ALTHROCIN 125mg kid tab
•
E ethylsuccinate- ERYNATE
• Adverse effects : • GIT – epigastric pain • On high doses – hearing impairment • Hypersensitivity reactions – rare • Uses : • Substitute for penicillin, pencillin resistant infections • Oral adm, safe and effective • Perio/periapical/NUG/extraction • Prophylactic use • ROXITHROMYCIN • Semisynthetic - long acting, stable macrolide • Antibacterial spectrum similar to erythromycin • Dose - 150-300mg BD 30min before food • Children - 2.5-5mg/kg BD
• ROXID, ROXIBID 150,300mg tab • 50mg kid tab,150 mg tab • Clarithromycin – CLARIMAC 250,500mg tab • CLINDAMYCIN • It is lincosamide antibiotic having similar action (macrolide 50s) • Bacteriostatic – low conc;Bacteriocidal – high conc • Most active against gram+ve cocci, C.diphtheriae, Actinomyces • Highly active against – anaerobes (B fragilis) • Pharmacokinetics : • Oral absorption – good • Distribution – skeletal and soft tissues • Excreted in urine
• Adverse effects : • Rashes ,Urticaria • Abdominal pain • Superinfection -Enterocolitis &Diarrhoea • Uses : • Anaerobic and mixed infections- alternative to Pn & macro • Abscess and bone infections-staphy and bacteroids • Infective endocarditis • Doses : 150-300 mg QID oral ; 200-600mg I.v. 8 hourly
• DALCAP, CLINCIN, DALCIN, 150, 300 mg cap, 300mg/2ml and 600 mg/4ml inj. • Anti fungal drugs • Fungus • Composed of a rigid cell wall made up of chitin and various polysaccharides, and a cell membrane containing ergosterol • Protective layers of the fungal cell make the organism resistant to antibiotics • Related groups of anti fungal agents • 1.Antibiotics • A. Polyenes • B. Heterocyclic benzofuram • 2.Antimetabolites • 3. Azoles • A.Imidazoles • B.Triazoles • 4.Allylamine • 5.Topical agents • Nystatin • A polyene derived from Streptomyces noursei • Binds to sterols of fungal cell membrane • Topical antifungal agent- fungicidal • 2nd choice to clotrimazole • 1 lac units-4 times a day, 10-14 days • Suspended with glycerine
• CLOTRIMAZOLE • Effective in the topical treatment. Esp, athletes foot, otomycosis and oral, cutaneous candidiasis. • 10mg -3-4times a day. Gel or lotion-denture stomatitis • Angular chelitis • well tolerated although Local irritation and burning • No systemic toxicity is seen after topical use. • SURFAZ, CLOTRIN, CLODERM, 1% lotion, cream, powder 100mg tab. • ANTIVIRAL DRUGS • Anti-herpes virus • Idoxuridine,acylovir,famiclovir • Anti-retrovirus • NRTI • Zidovudine • Lamivudine • NNRTI • nevirapine • PI • Ritonavir • Indinavir
• Antiinnfluenza virus • Amantadine • Nonselective antiviral drugs-ribavirin • Acyclovir • Indications: Herpes simplex virus (HSV) 1 and 2 infections; HSV encephalitis; shingles and chickenpox; ointment for herpes infections; cream for cold sores • Actions: Inhibits viral DNA replication • Symptoms • Rapid progressing- facial cellulitis-HI/SP • Chronic/ slowly progressing-odontogenic- staphylococcal/mixed • >101 F –nonodontogenic- hospitalization • Colour:red/ violecious • Swelling: indurated, non fluctuant or erythematous – cellulitis • Pointed, fluctuant or productive- abscess • Management • Upper face • Outpatient: amoxicillin clavulanate or cefaclor orally • Ceftriaxone- 1 day iv • Inpatient : cefuroxime/ ampicillin+ sulbactam 7-10 days • Odontogenic –pencillin/ clindamycin, surgical intervention • Lower face • Outpatient: cephalexin, amoxicillin clavuanate, erythromycin • Inpatient : iv cefazolin, clindamycin
• Some of the commonly used drugs • Amox-250,500mg-tid • 250mg-Rs 67.50 • 500mg-Rs120.80 Children20-40mg/kg body weight-tid -125,250mg
• Cephalexin(sporidex) • 250,500mg • 250mg-10tab-Rs66.50 • 500mg-10tab-Rs120.50 • 125mg,250mg/5ml • 125mg;30ml-Rs34.50 • 250mg;30ml-Rs52.60 • Sporidex dispersible tabs • 125mg-10tabs-Rs32.25 • 250mg-10tabs-Rs69.95 • Paed drops-100mg/ml • 10ml-Rs33
• Metrogyl • 200mg;tab 10-Rs3.64
• 400mg;tab 10-6.31- given tid for 5-10 days • Suspension; 200mg /5ml-30ml-Rs8.09 • 60ml-Rs-12.27
• List of references • Essentials of medical pharmacology : • KD TRIPATHI; 5th edi. • Clinical pharmacology – Bennet & Brown 9th ed • Oral & maxillofacial infections – Topazian 4th ed • .Text book of pediatric dentistry – Damle 3rd ed • Caranza Text book of periodontology 10th