Disadvantages of Information Technology Essay Example

Disadvantages of Information Technology Essay Example Disadvantages of Information Technology Essay Disadvantages of Information Technology Essay Keep in mind that Isonaizd(INH) is the established treatment for preventive therapy , and the usual regimen is up to 300mg daily for adults. You can keep pts on for 6 months or 12 months with a positive CXR. Always give vitB6 when treating pts with INH. If there is a suspected resistance then use Rifampin (RIF) alone or in combo with the said INH. How do we treat current CLASSES III IV diseases. The first line medications are used in combinations since these tend to delay the development of resistance and to enhance activity. INH(p. o. or IM) 300mg. nhibits synthesis of mycolic acid in the bacterial cell wall thus making it easy to kill the organism in the dividing stage. The drug is however, bacteriostatic for the bacilli in the stationary phase. The drug is metabolized by N-acetyl transferase. Some of side effects include paresthesia, fever, convulsions, hepatotoxic, optic neuritis and Hemolysis in G6PD deficient pts. High level resistance involves deletion in the katG gene that c odes for catalase, and low-level resistance involves deletions in the inhA gene that codes for the target acyl carrier protein. Keep in mind that genotypic variability exists with FAST ACETYLATORS needing high doses of INH. Remember for the boards that Vit B6 will offset the neurotoxicity. RIFAMPIN(RIF) GOOD against Mycobacterium tuberculosis very bacteriocidal against it. Also against M. leprae. Can be used prophylactically in meningitis. The drug suppress the initial step of RNA synthesis by inhibiting DNA dependent RNA polymerase, and resistance occurs via change in polymerase sensitivity to inhibition. The drug undergoes hepatic metabolism to red-orange colored metabolites. So let the patient know that the urine and feces will be red-orange in color. Nausea ,vomiting, rashes, fever, jaundice and flu like symptoms with high doses. This drug will reduce the efficacy of anticonvulsants,contraceptive steroids and warfarin so take note for your boards and clinical treatment. PYRAZINAMIDE(PZA): Good for short term use and initial therapy with INH and RIF. The precise target of this drug is not well understood. Works well when bacteria is dividing very bacteriocidal at that point. The drug requires bioactivation. Can cause gouty attacks, liver dysfunction, phototoxicity, hyperuricemia, exacerabation of porphryia, polyarthralgia. ETHAMBUTOL(EMB): Great against M. tuberculosis and kansasii. The drug inhibits synthesis of arabinogalactan a component of mycobacterial cell wall. The side effects are dose dependent, and most common are optic neuritis,and gout. So we have looked at the first line drugs for treating TB, but keep in mind that daily intake of Alcohol increases the risk of hepatitis in patients on INH. In females on oral contraceptives increase the dosages or change to another form of contraceptive. RIF will also decrease methadone activity in pts on it so increase the methadone dosage by 50% . In treating pregnant patients the initial combination should be INH, RIF and EMB along with B6. Do not use PZA it is TERATOGENIC, do not use STREPTOMYCIN also will cause deafness. In fact let me mention some antibiotics to be AVOIDED IN PREGNANCY. : Aminoglycosides – ototoxic in developing fetus, Clarithromycin-embryotoxic Erythromycin estolate- increases incidence of cholestasis in the pregnant patient. Fluoroquinolones- deleterious effect on collagen metabolism Tetracyclines- interfere with bone and tooth formation via calcium chelation Sulfonamides- not to be used in third trimester can displace bilirubin from plasma proteins in the fetus and neonate causing KERNICTERUS. Metronidazole – mutagenic. OK let me get back to TB treatment. The second line drugs are Aminosalicylic acid, Ethionamide, Cycloserene, Streptomycin, ciprofloxacin, Oflofloxacin, Kanamycin or Capreomycin Amniosalicyclic acid: This is a bacteriostatic drug used in the treatment of TB and has good distribution but is not seen in the CSF. It is a competitive inhibitor of PABA in folate synthesis, and is eliminated in the urine. So do not use in patients with renal failure. However, the drug has been associated with causing HYPOTHYROIDISM, acute hemolytic anemia and GI distress. If used with ethionamide can become hepatotoxic. P. O. Ethionamide – This is a structural analog of INH and inhibits acetylation of INH. The drug is seen IN CSF However, the mechanism of action is not quite clear but it is known to cause peripheral neuropathies, GI distress, optic neuritis and is hepatototoxic. The drug is excreted in the urine and has a metallic taste. P. O. Cycloserine This tuberculostatic and its mechanism of action is unknown you never use it alone. Do not use it in pts with epilepsy since it will exacerbate the condition. The main side effect is peripheral neuropathies , Headaches, psychosis,depression so you can appreciate its CNS effects . nd it is excreted in the urine. P. O. Streptomycin – This was actually the first antibiotic that was used effectively to treat TB given IM but cause hypokalemia, hypomagnesemia, auditory and renal toxicity. You can now understand why it is no longer a first line drug due to the side effects. Ciprofloxacin – P. O. I have already discussed this . Oflofloxacin – P. O. similar in action to Ciprofloxacin Kanamycin )IV, IM, Both of these drugs are useful but their side effects include auditory, vestibular Capreomycin)IV, IM, and renal toxicity. Hypokalema and eosinophilia. Let us now shift to the attention to antibiotics that inhibit bacterial wall synthesis. These agents that attack the bacterial cell wall in order to be maximally effective require actively proliferating organisms because they have little effect on organisms that are not growing. The B-Lactams are the most important for this activity and these are the PENICILLINS. Their mechanism of action is to interfere with the LAST STEP OF PEPTIDOGLYCAN SYNTHESIS .. The antibiotics will bind to and inactivate proteins present on the bacterial cell membrane. Thus morphological changes or lysis of susceptible bacteria will occur. There is also inhibition of the transpeptidase step, thus hindering the formation of the crosslinks essential for cell wall integrity. So cell wall synthesis is blocked. What will accumulate in the bacteria are the â€Å"PARK PEPTIDE† (UDP-acetylmuramyl-L-Ala-D-Gln-L-Lys-D-Ala-D-Ala) . The natural Penicillins are G and V. Pen G is used in infections caused by Gm + and Gm – cocci, Gm + bacilli and spirochetes. This is less acid stable and is given IV or IM. Great for syphilis, gonorrhea and Pneumococcal pneumonia. Pen V is similar to Pen G but is given P. O. and is more acid stable than Pen G. Never use Pen V to treat septicemia. Keep in mind that B-lactamase bacteria are resistant to the the drug. Oh let me mention this in passing one of the ways to prevent GONOCOCCAL OPHTHALMIA in newborns where the mother has gonorrhea is by the use of SILVER NITRATE DROPS in the eyes. ANTISTAPHYLOCOCCAL PENICILLINS- Methicillin, nafcillin, oxacillin, dicloxacillin these are penicillinase resistant penicillins. Their use is usually restricted in treating infections caused by penicillinase-producing staphylococci. Keep in mind that METHICILLIN RESISTANT STRAINS are usually susceptible to Vancomycin, rifampin, ciprofloxacin, or imipenem/cilastatin. EXTENDED SPECTRUM PENICILLINS:- Ampicillin and Amoxicillin. These are less potent than Pen G against Gm+ and Gm- cocci. However, ampicillin is the drug of choice against Gm+ Bacillus. We are now beginning to see resistance to these antibiotics so you can add a beta-lactamase inhibitor such as CLAVULANIC ACID or SULBACTAM so as to protect the penicillins from enzymatic action. ANTIPSEUDOMONAL PENICILLINS: Carbenicillin, ticarcillin, piperacillin are useful in pseudomonal infections, and of the three piperacillin is the most potent. Combining ticarcillin with clavulanic acid will give you a broader spectrum so you get more bang for your buck. PENICILLINS AND AMINOGLYCOSIDES: The antibacterial effects of B-lactam antibiotics are synergistic with the aminoglycosides but NEVER! NEVER! Place both of them in the same INFUSION FLUID because the positively charged aminoglycosides will form an INACTIVE COMPLEX with the negatively charged penicillins. Some basic rules of administration: Methicillin, ticarcilloin, carbenicillin, meziocillin,piperacillin, azocillin and ampicillin plus sulbactam must be given IV or IM. You can get Pen V or Amoxicillin combined with Clavulanic acid P. O. There is a REPOSITORY or DEPOT form of penicillin and this is PROCAINE PENICILLIN G and BENZATHTHINE PENICILLIN G they are given IM and are slowly absorbed into the circulation. As a rule most of the penicillins are incompletely absorbed after p. o administration but they reach the intestine in sufficient amounts. However, AMOXICILLIN is almost completely absorbed. THUS it is not appropriate therapy for SALMONELLA derived enteritis. Since effective levels do not reach the organism in the intestinal crypts. Food will impede ALL PENICILLINASE RESISTANT PENICILLINS therefore they should be taken 30 – 60 minutes before meals or 2 – 3 hours after meals. Be reminded that other penicillins are less affected by food. Primary route of excretion via kidneys. The drug PROBENICID will inhibit secretion of penicillins. Adverse reactions include hypersensitivity, diarrhea, nephritis(seen more with methicillin), neurotoxic so be careful with the EPILEPTIC patient. Platelet dysfunction, (seen more with ticarcillin and carbenicillin) NEXT STOP CEPHALOSPORINS. These are B-lactam antibiotics and are closely related to penicillins structurally and functionally, and have the same mode of action and mechanism of resistance as the penicillins, but tend to be more resistant than the penicillins to B-Lactamase. Cephalosporins have been classified as first, second, third and fourth generations largely on the basis of bacterial susceptibility patterns and resistance to B-lactamases. Clinical uses vary depending on the generation of the drug. First Gen: Cefazolin, cephalexin, cefadroxil – great for Gm+ cocci, E. coli, Klebsiella pneumonae, and some proteus species. Also Penicillin G resistant staph. Second Gen: cefotetan, cefaclor, cefoxitin useful against Gm- bacilli, including B. fragilis(cefotetan) H. influenza, enterobacter aerogenes, neisseria species and Moraxella catarrhalis. Third Gen: Many Gm= and Gm- cocci and Gm- bacilli including B-lactamase forming strains. Ceftazidime (Pseudomonas), ceftizoxime (anerobes), ceftriaxone and cefixime(gonococci), cefotaxamine(antagonizes Vit K), cefoperazole,moxalactam. Fourth Gen: Cefipime This drug combines the Gm+ activity of the first generation with the Gm- activity of the third generation drugs. Please keep in mind that cephalosporins have some limitations: a. The third and fourth generations have a wide spectrum of antibacterial action that includes many significant pathogens. b. There are gaps in the antibacterial activity of cephalosporins c. None of the cephalosporins have clinically useful activity in the treatment of infections caused by methicillin resistant staphylococci, Listeria species, enterococci or â€Å"atypical† organisms such as Mycoplasma pneumonae and Chlamydia. The mechanism of action similar to Penicillins, and the mechanisms of resistance are essentially the same as those for penicillin. All cephalosporins except CEFADROXIL, CEPHRADINE(1st), CEFACLOR(2ND), and CEFIXIME(3rd) must be administered via IV. Due to poor oral absorption. All of them distribute very well into the body fluids but only with the 3rd gen you get adequate levels in the CSF especially with CEFOTAXAMINE which isused to treat meningitis caused by H. influenza. Elimination of cephalosporins is by tubular secretion and or glomerular filtration. Thus dosage must be adjusted in pts with renal failure. However, Cefoperazone and Ceftriaxone are EXCRETED THRU BILE into the FECES, and can be used in pts with renal insufficiency. Among the side effects of cephalosporins are allergic manifestations in that 15% of individuals allergic to penicillins will show cross-sensitivity whereas the allergic reactions to cephalosporins is 1 2%. There is a disulfiram-like EFFECT when CEFAMANDOLE, CEFOPERAZONE and MOXALACTAM are ingested with alcohol or alcohol-containing medications. These drugs will block the second step in alcohol oxidation which results in accumulation of acetaldehyde. In fact these same three drugs can also cause bleeding because of anti-vit K effects. So give Vit K to correct the problem of bleeding. Let us look at the other B-Lactam antibiotics. CARBAPENEMS- These are IV drugs which are eliminated via the kidneys so you have to reduce the dosage in renal dysfunction patients. The carbipenems are IMIPENEM and MEROPENEM, and they are bacteriocidal and have a wide activity against Gm+ and Gm- bacteria including anerobes. Very good in Empiric therapy pending lab results. Imipenem is used with CILASTATIN which blocks its metabolism by renal dihydropeptidases. Nausea, vomiting, diarrhea, skin rashes and seizures are among the adverse effects. MONOBACTAMS AZTREONAM is capable of disrupting cell wall synthesis but has a narrow spectrum and cannot be used alone in empiric therapy. It is resistant to B- lactamases. Used IM or IV and is excreted in the urine so it can accumulate in pts with renal problems. However, the drug is relatively non toxic although it can cause phlebitis, skin rash and occasionally abnormal liver function tests. This is a safe alternative for treating patients allergic to penicillin. B-Lactamase Inhibitors. Clavulanic acid, sulbactam. These protect penicillin derivatives from enzymatic inactivation by B-lactamases. Note ; clavulanic acid alone barely has antibacterial activity. We now arrive at the big gun, VANCOMYCIN a bacteriocidal wall inhibitor of glycosylation ractions by binding to the D-Ala-D-Ala terminal of the peptide chains of peptidoglycans. Resistance involves decreased binding of the drug via replacement of the terminal D-Ala-by D-lactate. It is used mainly for severe infections caused by methicillin resistant staph, pseudomembraneous colitis caused by C. difficile, allergies to penicillin,used prophylactically in dental patients with prosthetic heart valves. Resistrance rarely occurs with it, and slow IV infusion is used to treat systemic infections. Drug is excreted via glomerular filtration. The side effects are serious ; dose-related ototoxicity is associated with serum levels above 80ug/ml. Nephrotoxicity may occur in some pts, fever, chills or phlebitis can occur at the site of infusion. Shock has occurred in pts when infusion is rapid. Rashes may be seen in chronic administration. I want you to remember this for the boards if a pt has ANTIBIOTIC –INDUCED COLITIS give VANCOMYCIN p. o. since it is not absorbed after oral administration.