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Review Chapter 7 Are antibiotics useful in treatment caries? NO BECAUSE…DECAY NEEDS TO BE TREATED WITH A FILLING NOT ANTIBIOTICS PRODUCED BY: STREPTOCOCCUS MUTANS For a localized dental infection, when is drainage applied? FIRST IF DRAINAGE CANNOT BE DONE OR IF THE CLIENT IS IMMUNOCOMPROMISED…ANTIBIOTICS ARE GIVEN WHAT IS Pseudomembranous colitis? INFLAMMATION OF THE COLON WHEN GIVEN CLINDAMYCIN PSEUDOMEMBRANOUS COLITIS, A CAUSE OF ANTIBIOTIC ASSOCIATED DIARRHEA (AAD), IS AN INFLAMMATION OF THE COLON Remember… DEFINITIONS The ability to kill bacteria; effect is irreversible The ability to inhibit or retard the multiplication or growth of bacteria; reversible Concentration of the antiinfective agent present in the blood or serum. • The importance of the serum level is that certain levels of an antibiotic are required to produce an effect on various types of organisms. For an antibiotic to be effective, the dose given must produce this DEFINITIONS – Infection caused by proliferation of microorganisms different from those causing the original infection • Superinfection is more often caused by broadspectrum antibiotics and increases when taken for a longer time period. – In this case, a reduction in the number of gram positive and gram-negative bacteria allows the overgrowth of the fungus Candida albicans. • The pathogenic organisms emerging in a superinfection generally are more difficult to eradicate than the original organism and more likely to exhibit resistance. – most are caused by Staph or Strep – The practitioner can cause and eliminate infections DEFINITIONS The difference among the terms antibiotic, antiinfective, and antibacterial is that antibiotics are produced by microorganisms, whereas the other agents may be developed in a chemistry laboratory (not from a living organism). – substances that act against or destroy infections – substance that inhibits or kills organisms that can produce infection, such as bacteria, protozoa, viruses etc. – Substances that destroy or suppress the growth or multiplication of bacteria ― Chemical substances produced by microorganisms that have the capacity, in dilute solutions, to destroy or suppress the growth or multiplication of organisms or prevent their action WHAT DOES CULTURING MEAN? MEANS GROWING THE BACTERIA CULTURE AND SENSITIVITY IS THE ONLY WAY TO BE SURE A DRUG WILL KILL OR INHIBIT THE GROWTH OF THE INFECTING MICROORGANISMS. Sensitivity involves exposing the organism to test antibiotics and determining whether the organism is sensitive or resistant An antibiotic disk with a zone around it shows sensitivity. After the organism is identified, it is grown on culture medium. Observing whether the organisms are sensitive or resistant to certain test antibiotics assists in determining which antibiotic to use in difficult infections. One to two days are required before the results of the test are available. Although antibiotic therapy can start before this time, it may be changed after the results are available. THEREFORE, Antibiotic therapy CAN be initiated BEFORE the results of the test are available. If clinical response has been adequate, the original antibiotic is often continued despite sensitivity results. MEANS GROWING THE BACTERIA CULTURE AND SENSITIVITY IS THE ONLY WAY TO BE SURE A DRUG WILL KILL OR INHIBIT THE GROWTH OF THE INFECTING MICROORGANISMS. Sensitivity involves exposing the organism to test antibiotics and determining whether the organism is sensitive or resistant WHAT IS SUPERINFECTION? AN OVERGROWTH OF ORGANISMS PRODUCED WHAT ANTIBIOTIC HAS THE HIGHEST INCIDENCE OF GI COMPLIANTS? ERYTHROMYCIN GENERAL ADVERSE REACTIONS & DISADVANTAGES ASSOCIATED WITH ANTIINFECTIVE AGENTS – Antimicrobial agents that can be used during pregnancy to treat infections are limited • Penicillin and erythromycin have NOT been associated with teratogenicity and are often used – Before any antibiotics are used in the pregnant dental patient, the patient’s obstetrician should be contacted • Metronidazole is not usually used & Tetracyclines are contraindicated – Tetracycline: because of their effect on developing teeth and skeleton MUST KNOW.. • Divided into 4 groups: 1. Penicillin G and V ** 2. Penicillinase-resistant penicillins 3. Ampicillins – includes amoxicillin ** 4. Extended-spectrum penicillins ** most commonly used in dentistry Within the group ONLY Penicillin G is considered to be the natural penicillin *See note • See Table 7-3; Page 83 for FYI review MUST KNOW.. WHAT IS THE MOST COMMON ANTIBIOTIC FOR DRUG ALLERGIES? PENICILLIN PENICILLINS THE SALTS OF PENCILLIN G • The potassium salt given intravenously produces the most rapid and highest blood level. • The penicillin’s duration of action is inversely proportional to the solubility of the penicillin form: the least soluble is the longest acting. • The benzathine salt given intramuscularly produces the lowest and most sustained blood level. PENICILLIN WHAT IS THE USUAL DOSE OF PEN V? 500 mg 4 times a day PENICILLINS • The usual adult dose of Pen V for treatment of an infection is: – 500 mg qid (4x a day) for the treatment of an infection – for a minimum of 5 days and preferably for 7 to 10 days. 500 mg 4 times a day WHAT IS CLEOCIN? CLINDAMYCIN RATIONAL USE OF ANTIINFECTIVE AGENTS IN DENTISTRY • Stage 1 • Stage 2 • Stage 3 RATIONAL USE OF ANTIINFECTIVE AGENTS IN DENTISTRY • Acute abscess and cellulitis are primarily the result of gram-positive organisms – THE DRUG OF CHOICE IS: penicillin V for patients who are not allergic to penicillin • 500 mg every 6 hours for 5 to 7 days – Erythromycin ethylsuccinate or clindamycin for patients who are allergic to penicillin RATIONAL USE OF ANTIINFECTIVE AGENTS IN DENTISTRY • Infection is mixed; can be handled by attacking either the gram (+) organisms or the (-) anaerobes Clindamycin or metronidazole would be the best choice to attack the anaerobes in a stage 2 infection – Gram-positive organisms can be managed with the same drugs as in stage 1(Erythromycin or clindamycin for patients who are allergic to penicillin) – For anaerobes, an antiinfective with good anaerobic coverage is needed • The two antibiotics with the most anaerobic coverage are clindamycin and metronidazole • Penicillin V also has anaerobic coverage RATIONAL USE OF ANTIINFECTIVE AGENTS IN DENTISTRY • The organisms have coalesced into one area and are almost solely anaerobic – Most often, incision and drainage is sufficient – If chronic infection persists or the patient is immune compromised, use of antibiotic with anaerobic coverage is warranted • Oral-cavity infections are generally understood to advance through three stages. – The three stages are: • (1) mixed aerobic and anaerobic infection, • (2) aerobic infection, • (3) anaerobic infection. – YET, what order do these stages occur? • THEREFORE, the order of the stages for oral infections occur as follows: • (2) aerobic infection, • (1) mixed aerobic and anaerobic infection, • (3) anaerobic infection. Chapter 8 WHAT ARE ANTIBIOTICS AND ANTIINFECTIVES NOT AFFECTIVE AGAINST? Fungal or Viral Infections IS FUNGUS ACUTE, CHRONIC, OR BOTH? CAN BE BOTH • ANTIFUNGAL AGENTS: Substances that destroy or suppress the growth or multiplication of fungi • Infrequent but when present, difficult to treat • Insidious (sneaky and quick) • More likely to occur on immunocompromised patients • Can become chronic (long-standing) • Can be divided into 2 divisions: FUNGAL INFECTIONS Mucocutaneous Systemic •skin or mucosa •whole body •commonly seen in •more serious in the dental setting nature •treated with topical or systemic antifungal agents •also, commonly occur in the vaginal canal HOW COULD AN ORAL CANDIDIASIS INFECTION BE TREATED IN THE MOUTH? AN ANTIFUNGAL.. ORAL CANDIDAL INFECTIONS ARE OFTEN TREATABLE WITH ORAL ANTIFUNGAL LOZENGES AND RINSES CANDIDA ALBICAN • is part of the normal flora; overgrows if patient is on long term antibiotics or ill fitting denture (Mycostatin, Nilstat) • is used for both the treatment and the prevention of oral candidiasis in susceptible cases. • poor oral absorption: • is not absorbed from the mucous membranes or through intact skin; taken orally, it is poorly absorbed from the GI tract. HOW COULD AN ORAL CANDIDIASIS INFECTION BE TREATED IN THE MOUTH? HOW LONG SHOULD A NYSTATIN RINSE REMAIN IN THE MOUTH? 2 minutes – for the BEST effect WHAT IS NICKNAMED ‘AMPHOTERRIBLE’? AMPHOTERICIN B • Amphotericin B poorest safety profile • Also known as Fungizone WHY ARE VIRUSES DIFFICULT TO TREAT? THEY CO-OPERATE WITH THE HOST CELLS MEANING…THEY WILL NOT DESTROY THE HOST OF A CELL Remember also… • • • • SUMMARY – KEY POINTS Works by inhibiting replication of DNA Food does not affect the drug’s absorption The antiviral action of acyclovir includes herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2), Epstein-Barr and varicellazoster One of the most common adverse effects associated with oral acyclovir is headache. • Anorexia and a funny taste in the mouth have been reported rarely (not common). Remember also… BY TAKING ABREVA – HOW MUCH IS HEALING TIME REDUCED? ONE HALF DAY (NOT MUCH ) WHAT IS THE CATEGORY OF DRUGS CALLED WHEN TREATING HIV? ANTI-RETROVIRAL DRUGS Examples of Drugs Used to Treat HIV SEE NOTE • Nucleoside reverse transcriptase inhibitor (NRTI) zidovudine (AZT) (Retrovir) • Nonnucleoside reverse transcriptase inhibitor (NNRTI) nevirapine (Viramune) – specific for HIV 1 • Protease Inhibitors saquinavir (Invirase) CHAPTER 9 WHY IS EPI USED IN LOCAL ANESTHETICS? PROLONG DURATION MEANING..THE LOCAL ANESTHETIC LASTS LONGER TO ENSURE PROPER FREEZING OF THE TOOTH AND TISSUES WHAT ARE SOME EXAMPLES OF LOCAL ANESTHETICS USED TODAY? • The amide lidocaine (Xylocaine) was released in 1952 • mepivacaine (Carbocaine) was released in 1960 • More recently, bupivacaine (Marcaine) has been made available for dental use potent local anaesthesia reversible local anaesthesia should be followed by complete recovery without evidence of structural or functional nerve damage absence of adverse systemic effects & allergic reactions rapid onset & good duration should have moderate lipid solubility which allows an anesthetic agent to diffuse across lipid membranes of all peripheral nerves (motor, sensory, autonomic) adequate tissue penetration low cost long shelf life (stability in solution) ease of metabolism & excretion WHAT ARE THE TWO GROUPS OF LOCAL ANESTHETICS? AMIDES AND ESTERS CROSS-HYPERSENSITIVITY BETWEEN AMIDES AND ESTERS IS UNLIKELY Absorption & L.A. local anaesthetic (L.A.) L.A. tooth • ↓ pH • ↑ ionization • ↑ [H+] infection L.A. L.A. EG: Lidocaine’s pKa =7.9(Weak base drug) *Weak bases are better absorbed when the pH is greater than the pKa In the presence of infection, there may be a reduced clinical effect of L.A. due to the ↓’d pH level. The infection site is more acidic and more ionized and less likely to absorb the L.A drug (weak base). IF INFECTION IS PRESENT, HOW DOES THE LOCAL ANESTHETIC REACT? IT IS HARDER TO FREEZE –LIKELY INFECTION MUST BE CLEARED BEFORE FREEZING IS DONE. IN THE PRESENCE OF AN ACIDIC ENVIRONMENT, SUCH AS INFECTION OR INFLAMMATION, THE AMOUNT OF FREE BASE IS REDUCED WHAT DOES ADME STAND FOR? VERY IMPORTANT! ABSORPTION DISTRIBUTION METABOLISM EXCRETION • Addition of vasoconstrictor to local anesthetic: Reduces the blood supply to the area so as to ↓ rate of diffusion of anaesthetic into the blood vessels this also prolongs the duration & effectiveness of the desired action decreases bleeding in the area Limits systemic absorption Reduces systemic toxicity LA agents are metabolized differently, depending on whether they are amides or esters. • AMIDES: are metabolized primarily by the liver • In severe liver disease or with alcoholism, amides may accumulate and produce systemic toxicity • ESTERS: are hydrolyzed by plasma pseudocholinesterases and liver esterases • Although toxicity to local anesthetics is rare in the doses normally used in dentistry, patients can still suffer from a classic toxic reaction. LOCAL ANESTHETIC TOXICITY causes stimulation of the CNS including: restlessness, tremors seizures followed by CNS depression and coma. HOW MANY CARPS ARE MAX FOR LIDOCAINE? 8.5 CARPS WHY WOULD A HEMATOMA BE PRODUCED? POOR INJECTION TECHNIQUE OR EXCESSIVE VOLUME • An autosomal dominant trait characterized by often fatal hyperthermia with rigidity of muscles occurring in affected people exposed to certain anaesthetic agents – particularly halothane & succinylcholine (G.A.’s) • NOT related to amides! – In the past, the belief was that the amide local anesthetics might precipitate malignant hyperthermia, but they are currently no longer implicated. Patients with a family history of malignant hyperthermia can be given amide local anesthetic agents. POOR INJECTION TECHNIQUE OR EXCESSIVE VOLUME IF A WOMAN IS PREGNANT AND ANESTHETIC MUST BE GIVEN… ..WHAT IS BEST? LIDOCAINE WHAT TYPE HAS A GREAT POTENTIAL FOR ALLERGY? AMIDES OR ESTERS? ESTERS I. Amides (Only class of anaesthetics used parenterally) i. ii. iii. iv. I. Lidocaine (Xylocaine) Mepivacaine (Carbocaine) prilocaine (Citanest; Citanest Forte) bupivacaine (bu·piv·a·caine) Esters (No esters are currently available in a dental cartridge) i. ii. iii. procaine propoxycaine Tetracaine **Esters are not used in dentistry as local anesthetics, but used topically. eg. Benzocaine. SEE NOTE LA AGENT NOTES • procaine • no longer used • lidocaine (Xylocaine) • most common used • least painful • can only use 100,000epi • mepivacaine (Carbocaine; Isocaine) • shortest duration • when no epi is needed. • bupivicaine (Marcaine) • Painful • longest duration 6-8 hours • articaine (Septocaine) • the most potent • prilocaine plain (Citanest) • similar to lidocaine • Prilocaine epi (Citanest Forte) • rapidly metabolized WHAT IS THE MOST COMMON LA USED IN DENTISTRY? LIDOCAINE 2% - (1:100 000 EPI) WHICH ONE HAS THE LONGEST DURATION OF ACTION? MARCAINE buprivacaine (Marcaine) • Has the longest duration of action. – major advantage greatly prolonged duration of action. – indicated in lengthy dental procedures when pulpal anesthesia of greater than 1.5 hours is needed or when postoperative pain is expected. • Related to lidocaine & mepivacaine • More potent but less toxic than the other amides • Available in dental cartridges as a 0.5% solution with 1:200,000 epinephrine WHAT IS BOTH AN ESTER AND AN AMIDE? ARTICAINE IF A CLIENT HAS UNCONTROLLED BLOOD PRESSURE – CAN LA BE GIVEN IN A CONTROLLED DOSE? NO – IT IS BEST TO DELAY TREATMENT A CARDIAC PATIENT can be given 2.0 CARTRIDGES of 1:100,000 epinephrine without exceeding the cardiac dose. WHAT IS THE MAXIMAL SAFE DOSE FOR A HEALTHY CLIENT? 0.2 MG OF EPI THE MAXIMAL SAFE DOSE OF EPINEPHRINE FOR THE HEALTHY PATIENT IS 0.2 MG AND FOR THE CARDIAC PATIENT IS 0.04 MG WHAT IS ORAQIX? SOMETHING THE RDH CAN USE TO FREEZE THE GUMS CHAPTER 10 CAN NITROUS OXIDE BE USED ALONE AS AN ANESTHETIC? NO! WHAT ARE THE STAGES/PLANES OF ANESTHESIA? STAGES… STAGE I – ANALGESIA STAGE II – DELIRIUM OR EXCITEMENT STAGE III – SURGICAL ANAESTHESIA STAGE IV – RESPIRATORY OR MEDULLARY PARALYSIS VERY IMPORTANT… Stage I – Induction Period Nitrous oxide, as used in the dental office, maintains the patient in STAGE I Analgesia Analgesia Amnesia Euphoria consciousness Stage II – Induction Period Excitement Excitement Delirium combativeness Stage III Surgical Where most major surgery is Anesthesia performed Divided into four planes Unconsciousness Regular respiration Decrease in eye movement loss of respiratory control Stage IV Respiratory arrest Cardiac depression and arrest No eye movement Medullary Depression VERY IMPORTANT… WHAT IS NITROUS OXIDE? COLORLESS AND ODOURLESS GAS ANTIANXIETY AGENT + ANALGESIC AGENT WHY IS NITROUS OXIDE NOT GOOD TO USE AS A GENERAL ANESTHETIC ALONE? MAC > 100 BECAUSE OF ITS LOW POTENCY (MAC > 100), IT IS UNSATISFACTORY AS A GENERAL ANESTHETIC WHEN USED ALONE IF, HOWEVER, ANESTHESIA IS FIRST INDUCED WITH A RAPIDLY ACTING IV AGENT AND N2O/O2 IS ADMINISTERED IN COMBINATION WITH A VOLATILE ANESTHETIC, EXCELLENT BALANCED ANESTHESIA IS PRODUCED THEREFORE, Nitrous oxide combined with a halogenated inhalational anesthetic (N2O/O2) DECREASES THE MAC • N2O/O2 is given throughout most surgical procedures that necessitate the use of general anesthesia because it reduces the concentration of other agents needed to obtain the desired depth of anesthesia. The average percentage of nitrous oxide required for patient comfort is 35%. • DELIVERY: 100% O2 (2-3 minutes) → N2O added in 510% increments → until patient response indicates level of sedation reached→ after termination of N2O, 100% O2 (at least 5 minutes) WHY SHOULD THE CLIENT BE PLACED ON 100% OXYGEN AFTERWARDS? TO AVOID DIFFUSION HYPOXIA WHAT COLOR IS THE NITROUS TANK? BLUE **REMEMBER THIS! • Complications have been the result of misuse or faulty installation of equipment • NO2 tank → blue • O2 tank → green DON’T GET THESE MIXED UP!! • Cylinders are “pin coded” to prevent mixing of cylinders and lines • NO2 concentration should be automatically limited and have a fail-safe system that shuts off automatically if the O2 runs out WHEN SHOULD NITROUS NOT BE USED? IF THEY HAVE TROUBLE BREATHING… USE OF NITROUS OXIDE IS CONTRAINDICATED IN PATIENTS WITH ANY TYPE OF UPPER RESPIRATORY OR PULMONARY OBSTRUCTION CHAPTER 11 KEEP IN MIND… • Stress or anxiety due to dental treatment can be treated with both pharmacologic and nonpharmacologic methods. • The treatment of choice is often dependent upon the patient and his or her stress level. • The normal sedative dose (calms normal patient without dental appointment) is not expected to produce calmness in the dental patient, • but the hypnotic dose (that which induces sleep in the normal patient) can often produce the desired degree of sedation KEEP IN MIND… WHAT IS THE MOST COMMON WAY TO TREAT ANXIOUS PATIENTS? ORAL SEDATIVES OR IV? ORAL SEDATIVES However, the dose of a particular antianxiety agent effective for a particular patient is vastly variable and thus, is NOT predictable. WHAT DOES A LARGER DOSE OF ANTANXIETY AGENTS PRODUCE? INDUCES SLEEP (A SMALL DOSE PRODUCES SEDATION) Antianxiety Agents Sedatives** Hypnotics ** can be sedative or hypnotic – depending on dose; larger doses provide hypnotic effect WHAT ARE THE MOST COMMON PRESCRIBED ANTI-ANXIETY DRUGS? SEE NOTE EXAMPLES alprazolam (Xanax) chlordiazepoxide (Librium) clonazepam (Klonopin) chlorazepate (Tranxene) diazepam (Valium) – very popular estazolam (ProSom) flurazepam (Dalmane) halazepam (Paxipam) lorazepam (Ativan) -newer form of benzodiazepines - popular midazolam (Versed) oxazepam (Serax) quazepam (Doral) temazepam (Restoril) triazolam (Halcion) WHAT IS THE PREFERRED AGENT USED FOR THE ELDERY? LORAZEPAM WHAT IS PTOSIS? DROOPING OF THE UPPER EYELID IF DRUGS ‘NEED’ TO BE TAKEN DURING PREGNANCY, WHEN IS THE BETTER TIME? 2ND TRIMESTER D U R I N G T H E 1 ST T R I M E S T E R , M A L F O R M A T I O N S H A V E B E E N REPORTED Remember.. OVERVIEW • Abuse & Addiction potential is less than that of the barbiturates • Physical dependence and tolerance can develop • Combining with other CNS depressants can reduce the safety and can become lethal • Overdose poisoning is rare; difficult to achieve when used alone • The addition of alcohol can result in coma, respiratory depression, hypotension, or hypothermia WHAT IS EMESIS? INDUCED VOMITTING USED WITH OVERDOSE – SUCH AS ACTIVATED CHARCOAL AND SALINE WHAT CAN BE USED TO REVERSE THE EFFECTS OF BENZODIAZEPINES? flumazenil (ROMAZICON), IN THE IV FORM WHAT ARE SOME WAYS TO MANAGE INSOMNIA? Insomnia Management The following habits should be followed to minimize insomnia : A. Light snack (warm milk) at bedtime B. Awake at 6 AM even if sleep only began at 5 AM C. Exercise during the day, but NOT within 3 hours of bedtime. D. Remaining in bed no longer than 20 minutes without sleeping WHAT ARE SOME WAYS TO MANAGE INSOMNIA? This next slide will likely be on the exam ..… • Absorption: barbiturates are well absorbed orally and rectally; used intravenously but not intramuscularly • Distribution: IV agents are inactivated by redistribution from site of action in the CNS, to muscles, and adipose tissue • Metabolism: short- and intermediate-acting barbiturates are rapidly and almost completely metabolized by the liver • Excretion: long-acting barbiturates are largely excreted through the kidneys as a free drug WHAT ARE LONG ACTING BARBITURATES USED FOR? USED FOR EPILEPSY phenobarbital (Luminal) most commonly used for its anticonvulsant effect because of its long-acting effects USED FOR EPILEPSY