1. PTP 546 Module 8 Pharmacology of Infections Jayne Hansche Lobert, MS, RN, ACNS-BC, NP 1Lobert

2. Pharmacology of Infections Antibacterial Drugs Terminology – Broad Spectrum Useful against a variety of bacteria – Selective or Narrow Spectrum Useful against a specific bacteria – Bactericidal Kills or destroys the bacteria – Bacteriostatic Limits growth and proliferation of the bacteria – Super Infections Secondary infections related to the destruction of normal flora 2Lobert

3. Pharmacology of Infections Antibacterial Drugs Mechanisms of Action of Antibacterial Drugs – Inhibition of bacterial cell wall synthesis and function – Inhibition of bacterial protein synthesis – Inhibition of bacterial DNA/RNA function 3Lobert

4. Pharmacology of Infections Antibacterial Drugs Resistant Bacteria – Cause Bacteria use natural and acquired defense mechanisms – Scope 60% of staph aureus infections are now resistant to penicillin (MRSA); there is now multidrug resistance (MDR); (VRE) – Prevention CDC Principles Prevent infections Use the right drug for the infection Limit the use of broad spectrum agents Increase the use of selective antimicrobial agents Limit the use of antibacterials Advise patients to take the full course of the antibiotic Prevent transmission of infections- #1 prevention 4Lobert

5. Pharmacology of Infections Antibacterial Drugs Penicillins – Natural Penicillins Ex: Penicillin G (Bicillin) – Penicillinase-resistant Ex: Methicillin (Staphcillin) – Aminopenicillins Ex: Amoxicillin (Amoxil)=5 th commonly prescribed – Extended Spectrum Ex: Piperacillin (Pipracil) Action: inhibit bacterial synthesis & function  bactericidal Therapeutic Effect: otitis, pneumonia, sinusitis, wound infections, uti’s, endocarditis, abscesses, syphilis, Side Effects: a significant potential for allergic reactions, diarrhea, nausea and vomiting 5Lobert

6. Pharmacology of Infections Antibacterial Drugs Cephalosporins – 1 st generation Ex:Cephalexin (Keflex) – 2 nd generation Ex:Cefoxitin (Mefoxin) – 3 rd generation Ex: Ceftriaxone (Rocephin) – 4 th generation Ex: Cefepime (Maxipime) Action: inhibits cell membrane synthesis  bactericidal Therapeutic Effect: meningitis, uti’s, bactremias, pneumonia, sinusitis, skin infections Side Effects: cross sensitivity with PCN  allergic response, diarrhea, nausea, vomiting 6Lobert

7. Pharmacology of Infections Antibacterial Drugs Other Agents – Ex: Imipenem & Cilastatin (Primaxin) Action: inhibits cell synthesis, then cilastatin inhibits inactivation of imipenem  enhanced bactericidal effects Therapeutic Effect: uti’s, bone & joint infections, respiratory tract infections, Side Effects: gi issues, rash, confusion, tremors, seizures 7Lobert

8. Pharmacology of Infections Antibacterial Drugs Other Agents – Ex: Vancomycin (Vancocin) Action: inhibits cell wall synthesis  bactericidal Therapeutic Effect: effective against life threatening life gram negative infections, treats Clostridium Difficile (C- diff) Side Effects: gi issues (horrific), phlebitis, nephrotoxicity (permanent kidney damage) and ototoxicity (hearing loss) Note: Issue of antibiotic resistance such as Vancomycin Resistance Enterococci (VRE) – Always orally, as it is better work in GI tract. 8Lobert

9. Pharmacology of Infections Antibacterial Drugs Aminoglycosides – Ex: Gentamycin (Garamycin) – Ex: Tobramycin (Nebcin) Action: inhibits bacterial protein synthesis  cell death Therapeutic Effect: life threatening infections, sepsis; hospital acquired infections; osteomyelitis Side Effects: ototoxicity and nephrotoxicity Note: requires careful monitoring for therapeutic blood levels to prevent adverse effects – Very serious medication. 9Lobert

10. Pharmacology of Infections Antibacterial Drugs Macrolides – Ex: Azithromycin (Azithromax)=15 th most common, also for ulcers – Ex: Clarithromycin (Biaxin) Action: inhibit bacterial protein synthesis; acts as a bacteriostatic Therapeutic Effect: upper respiratory tract infections, chronic bronchitis, cystic fibrosis; treatment of ulcer forming h pylori bacteria Side Effects: gi upset, diarrhea is common 10Lobert

11. Pharmacology of Infections Antibacterial Drugs Tetracyclines – Ex: Doxycycline (Vibramycin) – Ex: Tetraclycline (Achromycin) (used for ear infection in the past so caused blue staining of the teeth) Action: Inhibit bacterial protein synthesis  bacteriostatic Therapeutic Effect: treatment of chlamydia, gonorrhea, acne, anaerobic bacteria Side Effects: gi upset, rashes, discoloration of teeth, impairment of bone and tooth formation 11Lobert

12. Pharmacology of Infections Antibacterial Drugs (Newest for Resistant Strains) Other Agents – Ex: (1)Linezolid (Zyvox) – Ex: (2)Quinupristin & Dalfopristin (Synercid) – Ex: (3)Tigeycycline (Tygacil) Action: Inhibits protein synthesis Therapeutic Effect: useful for drug resistant strains like Methicillin Resistant Staph Aureus (MRSA) and VRE Side Effects: (all) gi distress, (3) headache, (2) joint and muscle pain, infusion site pain, (1) thrombocytopenia=bleeding 12Lobert

13. Pharmacology of Infections Antibacterial Drugs Fluroquinolones – Ex: Ciprofloxacin (Cipro) – Ex: Levofloxacin (Levaquin) – Ex: Moxifloxacin (Avelox) Action: inhibit bacterial DNA/RNA synthesis  cell death Therapeutic Effect: treatment of uti’s, anthrax, gonorrhea, skin infection, intraabdominal infections, Side Effects: gi upset, dizziness, confusion, insomnia, also suspected tendon issues. 13Lobert

14. Pharmacology of Infections Antibacterial Drugs Sulfonamides – Ex: (1)Sulfadiazine (Silvadene) – Ex: (2)Trimethopprim-Sulfamethoxazole (Bactrim) Action: alters folic acid synthesis  impaired RNA/DNA synthesis Therapeutic Effect: (1)topical agent to prevent infection in burns, (2)UTI’s Side Effects: gi distress, increased sensitivity to ultraviolet light, blood dyscrasias=cancer of the blood 14Lobert

15. Pharmacology of Infections Antibacterial Drugs Others – Ex: Metronidiazole (Flagyl) Action: inhibits RNA/DNA replication  bactericidal Therapeutic Effect: useful for anaerobic intraabdominal infections, gynecologic, skin bone and joint bacteria Side Effects: gi upset, peripheral neuropathies, confusion, dizziness, fatigue, weakness 15Lobert

16. Pharmacology of Infections Antibacterial Drugs Others – Ex: Rifampin (Rifadin) Action: inhibits RNA/DNA synthesis Therapeutic Effect: primarily used to treat tuberculosis Side Effects: gi distress, turns body secretions orangey-red, liver abnormalities and damage Note: used in conjunction with INH 16Lobert

17. Pharmacology of Infections Antibacterial Drugs Others – Ex: Isoniazid (INH) Action: inhibits cell wall synthesis Therapeutic Effect: treatment of active TB and prevention of tuberculosis when exposed Side Effects: peripheral neuropathies=numbness and tingling, with a high incidence Note: taken with Pyroxidine (B6) to prevent neuropathies, taken with Rifampin to treat TB 17Lobert