-DR. MEGHA SHAH

GUIDED BY DR. GARDE

MDS I DEPARTMENT OF ORAL AND MAXILLOFACIAL SURGERY

PENICILLINS 1ST antibiotic to be used clinically in 1941 MOA interferes with cell wall synthesis bactericidal Antibacterial spectrum Oral aerobes and anaerobes

Natural penicillins, aminopenicillins and penicillin resistance penicillins are mostly useful

Commonly used to treat infections in oral cavity To be used with precaution in Patients with hypersensitivity

NATURAL PENICILLINS Penicillin G Acid labile Parenteral route 2-5 million units IM (Adult Dose) Procaine penicillin G Longer acting Adequate serum levels for 8-12 hours, effective for 1-2 days when administered IM

Penicillin G Benzathine Even longer duration of serum levels Drug detectable for 1-3 weeks Penicillin V Acid stable 500mg QID orally

Spectrum of natural penicillins most gram + aerobes and most anaerobes. Staph. Aureus, bacteroides fragilis and H. influenza are commonly resistant to natural penicillins.

EXTENDED SPECTRUM AMPICILLIN Poorly absorbed from GIT Parenteral route

EXTENDED SPECTRUM AMOXICILLIN Currently indicated for treatment of orodental

infections.

Dosage / administration:

0.25 to 1 gm TDS. Mostly given orally. Trade namesMox, novamox, Alphamox, Ambac, 250 / 500 mg caps; 125 mg/ 5ml syrup Antibacterial spectrum-

Gram +ve, gram ve bacteria & most oral anaerobes.

ADVANTAGES Concentrations that are higher & last longer than an equivalent dose of Penicillin V. Effective against infections involving streptococci or other

species resistant to Penicillin V.

DISADVANTAGES Greater potential to produce superinfections of the GIT & vagina, because of broader spectrum of activity against gram ve aerobes. Can produce skin rashes as a result of allergy.

PENICILLIN WITH BLACTAMASE INHIBITORS Clavulanic acid A potent and irreversible inhibitor of many beta-lactamases Protects beta-lactam antibiotics from inactivation, when combined with them. Widens the antibacterial spectrum Common brand name and dosage Augmentin (amoxicillin 250/500mg + clavulanic acid 125mg) BD oral, Clavum Also as i.m. or i.v. 6 8 hourly asAugmentin (amoxicillin 1g + clavulanic acid 0.2g vial) Augmentin (amoxicillin 0.5g + clavulanic acid 0.1g vial)

Amoxicillin + Cloxacillin Novaclox, Amoclox, Amotox Tab 250mg + 200 mg TDSAdverse reactions Gastritis Hypersensitivity Abdominal cramps

Sulbactam Used with Ampicillin (Unasyn)

Improves ability to eradicate S.aureus and H.influenza

EXTENDED SPECTRUM PENICILLINS Spectrum includes aerobic gram-ve bacilli including

Ps. Aeruginosa Carbenicillin Ticarcillin Piperacillin Mecillinam Limited benefits in head and neck infections

CEPHALOSPORINS Less susceptible to b-lactamases as compared to

penicillin As the generation increases, gram positive coverage

reduces, while effectiveness for gram ve organisms increase and for anaerobes the killing power decreases Bactericidal

1st GENERATION CEPHALOSPORINS Commonly used for maxillofacial infections and

prophylaxis Cefadroxil Cephalexin

Cefazolin Cephradine Brand name and dosage cefadur, cefadrox, sporidex,

phexin Tab 500mg BD Active against streptococci sp, staph. Aureus and not active against enterococci, listeria or MRSA

2nd GENERATION CEPHALOSPORINS Greater gram ve spectrum More resistant to beta-lactamase. Cefaclor (250 mg cap; 125 & 250mg DT;

125mg/5ml dry syr)

Cefoxitin Cefprozil Cefuroxime Brand name and dosage Ceftab, Ceftum - Tab 500 mg BD Useful for treating upper & lower respiratory tract

infections, sinusitis & otitis media

3rd GENERATION CEPHALOSPORINS Broad spectrum of activity with further increased activity

against gram ve organisms. Cefixime Ceftriaxone Cefotaxime (0.25, 0.5 & 1 g per vial inj) Ceftibuten Cefdinir Cefpodoxime

Brand Name and dosage Zifi, Taxim o tab 200mg BD Promising for serious sinus and skin infections

4th GENERATION CEPHALOSPORINS Extended spectrum agents, with similar activity

against gram +ve organisms as first generation cephalosporins. generation cephalosporins.

Greater resistance to beta-lactamases than third

Cefluprenam Cefozopran Cefepime ( 0.5, 1 g inj) Cefpirome Cefquinome

Adverse effects:MildStomach upset / cramps Nausea, vomitting Diarrhoea Sore tongue Sores in the mouth Vaginal yeast infections SevereBlack, tarry stools Chest pain Fever Difficult / painful urination Allergic reactions Serious colitis

MONOBACTAMS Bactericidal effect similar to other drugs in this class Only Aztreonam is approved for use No activity against g+ organisms, limiting its use in

head or neck infections Dose 1-2 g every 8 hours

CARBAPENEMS Broad antibacterial spectrum Commonly used to treat P.aeruginosa infections

resistant to other antimicrobials IMIPENEM MEROPENEM

TETRACYCLINES Bacteriostatic in nature Limited use because of rapid development of

resistence MOA binding to 30S ribosomes Uses Lower molar osteitis sicca (dry socket ) prevention Acne therapy Periodontal disease

Effective against g+cocci and few g-ve rods Tetracycline, minocycline & doxycycline are used for

treatment of orodental infections Tetracycline HCl (Alcyclin, Tetracyn) - Cap/ tab for paediatric dose. Adult dose between 1 and 2 g/per day in 34 divided doses. Doxycycline - Sparadoz, Sydox Cap 100mg, Tab 200mg )D

Adverse effects: Teratogenic Stains developing teeth Allergic manifestations like rash Photosensitivity Hepatic dysfunction GI disturbance like nausea, vomiting, epigastric distress Antianabolic effect Avoided in patients with renal impairment can lead to aggravation of aztemia and exaggerated anabolic effect Reversible Fanconi-like syndrome IV administration can lad tolocal thrombosis

VANCOMYCIN

Highly effective against MRSA, gram + cocci MOA cell wall inhibition Poor oral absorption and painful IM injection IV dose 2g daily in divided doses 500mg over 60 mins every 6 hours or 1g every 12 hours Vancocin CP Cap 250mg QID Adverse reactions local thrombophlebitis, generalised cutaneous reactions (Red Man Syndrome) and auditory damage Used with caution in patients with renal damage

CHLORAMPHENICOL Broad spectrum, bactriostatic agent Rarely used these days Useful in ampicillin resistant H.influenza and

anaerobic bacteria Useful for brain abscess and meningitis S/E aplastic anaemia (rare)- gray baby syndrome (neonates)

50mg/kg/day in divided 4 doses in older children and

adults

MACROLIDES Useful for maxillofacial infections MOA bacteriostatic and interferes with protein

synthesis by attaching to 50S ribosome subunit Antibacterial spectrum g+organisms, G ve can resist it easily because of outer cell membrane and Methicillin resistant staph. Aureus is also resistant Common macrolides Erythromycin, Azithromycin, Clindamycin, Clarithromycin

ERYTHROMYCIN Best known macrolide with g + spectrum similar to

penicillin, but less effective against anaerobes. But not used much because of its side effects and other agents are preferred

CLINDAMYCIN Bacteriostatic at low concentrations and bactericidal at

slightly higher concentration Effective against gram + organisms, especially Staphylococci, Pneumococci, certain Streptococci Also useful for anaerobic infections Cap clincin, Dalacin 150 450 mg orally QID / 300 mg BD Adverse effect superinfection with Cl. Difficile Commonly used ddrug for serious odontogenic infections including osteomylitis

AZITHROMYCIN Broad spectrum coverage including g+ and g-ve

aerobes and strict anaerobes Oral absorption and tissue peneration is better Brand name and dosage Azith , Azec tab 500mg OD/BD

Adverse reactions : Diarrhoea Nausea Vomiting Flatulence Headache Rashes

NITROIMIDAZOLES METRONIDAZOLE Stimulates production of toxic products to kill

susceptible bactera Effective against strict anaerobic bacteria (mostresponsible for oral/dental infections- Bacteroides, Prevotella, Porphyromonas, Veillonella, Fusobacterium, Treponema etc.) Trade names & dosage:

Metrogyl, Flagyl 400mg tab TDS orally Can be given i.v. also (100 ml)

ORNIDAZOLE Trade name and dosage Orni, Ornida Tab 500mg

BD

Uses: Pericoronitis Certain periapical infections Some cases of osteomyelitis Infected extraction socket

Adverse reactions : Anorexia Nausea Abdominal cramps Dizziness Metallic taste

Adverse effects : Disulfiram reaction Can increase the action of anticoagulants Contraindicated in pregnant patients

FLUOROQUINOLONES: Quinolones are a family of synthetic broad spectrum

antibiotics. The parent of the quinolones class is nalidixic acid. Majority of quinolones in clinical use belong to the

subset of fluoroquinolones.

Generations: Quinolones are divided into generations based on their anti-bacterial spectrum.

1st generation Cinoxacine Nalidixic acid Oxolinic acid Rosoxacin Pipemidic acid Piromidic acid

2nd generation ciprofloxacin ofloxacin norfloxacin lomefloxacin nadifloxacin

3rd generation: 4th generation: (active against streptococci) Plurifloxacin Levofloxacin Gemifloxacin Sparfloxacin Clinafloxacin Balofloxacin Gatifloxacin Grepafloxacin Moxifloxacin Trade names: Ciplox, Cifran 250, 500 or 750mg tabs.; 200mg/100ml i.v. Norflox 200, 400, 800mg tabs

REFERENCESPharmacology and pharmacotherapeutics by R.S.Satoskar revised 20th edition 2. Essentials of medical pharmacology by K.D. Tripathi 5th edition1.