Pharmacology 1104

1. Pharmacology 1104 Drug Classifications & Characteristics of Antimicrobials

2. Purpose To prevent or treat infections caused by pathogenic (disease-producing) micro-organisims. Goal is to cure disease by eradicating causative microorganism and returning client to full physiologic functioning.

3. CHARACTERISISTICS:Terms and Concepts 1. Antimicrobial or anti-infective-drugs used to prevent or treat infections caused by pathogenic (disease-producing) microorganisms. Include antibacterial, antiviral, and antifungal drugs. 2. Antibacterial or antibiotic-usually refer only to drugs used in bacterial infections. 3. Antiviral- drugs used to treat viral infections. 4. Antifungal- drugs used to treat fungal infections. 5. Antiparasitic- drugs used to treat parasite infections or infestations.

4. Terms 6. Broad Spectrum- antibacterial drugs that are effective against several groups of microorganisims. 7. Narrow Spectrum- antibacterial drugs which are effective against only a few groups of microorganisms. 8. Bacteriocidal- action of an antibacterial drug in that it kills microorganisms. 9. Bacteriostatic- action of an antibacterial drug in that it inhibits growth of the microorganism. 10. Superinfection- a new or secondary infection that occurs during antimicrobial therapy of a primary infection.

5. Terms 11. Antibiotic combination therapy- use 2 or more drugs in combination to treat infections known or thought to be caused by multiple microorganisims, to get a synergistic effect, to prevent emergence of drug-resistance organisims, or to treat clients whose immune system is suppressed or client with bone marrow or organ transplant.

6. Mechanisms of Action: Most act on specific target in the bacterial cell. Almost any structure unique to bacteria (proteins or nucleic acids) can be a target.

7. Mechanisms of Action: 1. Inhibition of bacterial cell wall synthesis or activation of enzymes that disrupt bacterial cell walls-penicillins, cephalosporins, vancomycin. 2. Inhibition of protein synthesis by bacterial or production of abnormal bacterial proteins (bind irreversibly with bacterial ribosomes so cannot synthesize proteins)-aminoglycosides, clindamycin, erythromycin, tetra-cyclines. 3. Disruption of microbial cell membranes-antifungals. 4. Inhibition of organism production by interfereing with nucleic acid synthesis-fluoroquinolones, rifampin, anti-AIDS, antivirals. 5. Inhibition of cell metabolism and growth-sulfonamides, trimethoprim.

8. Indications for Use 1. To treat already existing infections. 2. To prevent development of infections (called prophylactic therapy). Recommended to prevent- a. Group A strep infections b. Bacterial endocarditis in clients with cardiac vascular disease who are having dental, surgical or other invasive procedures. c. TB-INH d. Perioperative infections in high-risk clients e. STD’s (gonorrhea, syphilis, chlamydia) after exposure has occurred. f. Recurrent UTI in premenopausal , sexually active women.

9. . Principles and Guidelines: 1. Dosage and route of administration should be individualized to each client. 2. Average duration of therapy for acute infections is 7-10 days- or until has been afebrile and asymptomatic for 48-72 hours. 3. Schedule at evenly spaced intervals around the clock. 4. Take most on empty stomach ( 1 hour before or 2 hours after meals) and with full glass of water. 5. Follow label instructions for mixing and storing of drugs.

10. . Principles and Guidelines: 6. Check expiration dates. 7. Do not mix parenteral solutions with other drugs. 8. Give IM doses deeply into large muscle mass and rotate sites. 9. For IV doses give slowly over 30-60 minutes and flush IV tubing after. 10. Always observe for therapeutic effects.

11. Adverse Effects Hypersensitivity Anaphylaxis Serum sickness Acute interstitial nephritis Super Infection Recurrence of systemic S & S New localized S & S Stomatitis or thrush Pseudomembranous colitis Monilial vaginitis

12. Adverse Effects c. Phlebitis d. N & V e. Diarrhea f. Nephrotoxicity g. Neurotoxicity- confusion, hallucinations, neuromuscular irritability, seizures h. Bleeding- platelet dysfunction.

13. Principles and Guidelines 12. Always observe for drug interactions. 13. Client education a. Must take all prescribed dose and not stop when symptoms subside. b. Must not take meds left over from previous illness or prescribed for someone else. c. Must report all other drugs being taken- drug interactions may occur. d. Must report all drug allergies. e. Some antibiotics ( ampicillin, nitrofurantoin, PCN V, sulfonamides, tetracyclines) decrease effectiveness of estrogens and oral contraceptives- must be told to use another method of contraception. 14. Hypersensitivity to a drug is always a contraindication for that drug.