ANTIVIRALS & ANTIBACTERIALS

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Cheryl Davis-Triplett

WHAT IS A VIRUS? Obligate intracellular

organism that uses the cell to reproduce. They replicate by using their own RNA or DNA to manipulate the cells they infect

They cause cell death

WHAT IS A BACTERIA? Smallest living

cell. They have a cell wall and a cell membrane. They do not have a nucleus.

Bacteria divide by cell division.

HOW DO WE FIGHT BACTERIA AND VIRUSES

Antibacterials work with the body’s own defenses to stop the infection process.

Antivirals prevent or delay the speed of viral replication.

ANTIBACTERIAL MODE OF ACTION

Inhibit cell wall synthesis. Which Antibiotic class uses this mode?

Penicillins and Cephalosporins

Inhibit protein synthesis. Which Antibiotic class uses this mode?

Tetracyclines, Macrolides, and Aminoglydosides

MODE OF ACTION (cont.) Inhibit nucleic acid

synthesis. Which Antibiotic class uses this mode?

Fluoroquinolones

Inhibit folic acid synthesis. Which Antibiotic class uses this mode?

Sulfonamides

MODE OF ACTION (cont.) Alteration in

membrane permeability. Which drugs use this mode?

Ampho-TERRIBLE B, Nystatin, Polymyxin, and Colistin

ANTIVIRAL MODE OF ACTION Viruses enter

healthy cells and use their deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) to generate more viruses.

The growth cycle of viruses depends on the host cell enzymes and cell substrates for viral replication.

Viruses live and reproduce when they are within living cells.

OVERVIEW Penicillins Cephalopsporins Macrolides Tetracyclines Aminoglycosides Fluorquinalones Sulfonomides Antivirals

Viral flu treatment (drugs and how/when they are given)

Herpes simplex Aminoglycosides

(SE/ADEs, drug-drug) Otitis media

treatment Amphotericin B

Common factors among Antibiotics

Indications: bacterial infections SE/AD: superinfections, NVD Contraindications: hypersensitivity Interventions: C&S Pt Teaching: S&S hypersensitivity, finish

prescribed dose, medical alert bracelet

PENICILLINIndication for Use

Respiratory tract infection

Urinary tract infection

Otitis media Sinusitis

Example Drug Amoxicillin(Amoxil

)

PENICILLIN (cont.)Side Effects

NVD, rash, edema, stomatitis

AR: Super Infections (vaginitis)

Life threatening: Blood dyscrasias, hemolytic anemia, bone marrow depression, respiratory distress

Contraindications Allergy to

penicillin Severe renal

disorder

PENICILLIN (cont.)Interactions

Drug: asprin, tetracycline, erythromycin.

Lab: AST, ALT, BUN, and creatinine.

Food: acidic fruits or juices.

High Risk Populations

Geriatrics

PENICILLINNursing Process

Assess allergy to penicillin or cephalosporin.

Interventions: don’t mix aminoglycosides w/ penicillin G, check for bleeding, monitor temperature, dilute IV antibiotic.

Evaluate effectivess of med by determining if infection ceased and whether SE have occurred.

Client Education encourage client to

increase fluid intake instruct client that

chewable tablets must be chewed or crushed before swallowing

advise client to take medication with food to avoid GI irritation.

CEPHALOSPORINIndications for UseSkin, urinary and respiratory infections. Can also treat genital, bone joint infections and endocarditis.

Example DRUG Cefazolin (Ancef),

(Ketzol)

CEPHALOSPORIN (cont.)Side EffectsAnorexia, NVD, rash, abdominal cramps AR: superinfections, urticaria LIFE THREAT: seizures (high doses), anaphylaxis

ContraindicationsHypersensitivity to this antibiotic, watch for PCN allergies. Renal disease, lactation for mothers

CEPHALOSPORIN (cont.)Interactions

Drug: ETOH loop diuretics,

aminoglycosides, tetracyclines and

erythromycinLab: BUN, serum

creatinine, AST, ALT, ALP, LDG, and bilirubin.

High Risk Populations

persons allergic to PCN may also be allergic to cephalosporins

CEPHALOSPORINNursing Process

record VS and urine output

check lab results especially those that indicate renal and liver function-report abnormal findings

Client Education advise client to

ingest buttermilk or yogurt to prevent superinfection of the intestinal flora,

infuse IV cephalosporins over 30min

MACROLIDEIndications for UseFor patients with PCN allergiestreats gram positive and some gram negative bacteria, respiratory and skin infections and gonorrhea

Example DRUG Azithromycin

(Zithromax), (AzaSite)

MACROLIDE (cont.)Side EffectsSE: NVD,anorexia, rash, tinnitus, pruritus AR: hearing loss, vaginitis, superinfections, stomatitis LIFE THREAT: Hepatotoxicity, anaphylaxisUncommon: abdominal Pain , diarrhea(p. 427)

ContraindicationsHepatic or renal dysfunction, hypersensitivity, lactaction

MACROLIDE (cont.)Interactions

Drug: digoxin, theophylline

(bronchodilator), and warfarin (anticoagulant)

penicillins and clindamycin

antacids clindamycin or

lincomycinFood: administer 1 h before or

2 h after meals. fruit juice.

High Risk Populations

Liver toxicity can occur if taken with high doses of other hepatogoxic drugs (acetaminophen), phenothiazines, and sulfonamides.

MACROLIDE

Nursing Process check lab tests to determine

liver function, obtain a Hx of drugs client

takes-peak level of azithromycin may be decreased by antacids

Interventions: monitor vital signs and client for liver damage resulting from prolonged use

administer oral meds 1hr before or 2hrs after meals

do not give w/ fruit juice, dilute IV meds

administer antacids 2hrs before or 2hrs after azithromycin.

Client Education Instruct client to

take the full course of antibacterial agent as prescribed. Drug compliance is most important for all antibacterials (antibiotics).

TETRACYLINEIndications for UseTreat both gram positive and gram negative bacteria, skin and respiratory infections, syphilis, gonorrhea, chlamydia, ricketts and rosacea

Example DRUG Doxycline

(Vibramycin), (Vibra-Tabs)

TETRACYCLINE (cont.)Side EffectsAbdominal discomfort, rash, HA, pruritus, color vision change, photosensitivity AR: superinfection and severe photosensitivity LIFE THREAT: Hepatotoxicity, blood dyscrasias, intracranial HTN, psuedomembranous colitis

ContraindicationsSevere renal or hepatic disease, pregnancy, hypersensitivity, Caution: hypokalemia, bradycardia, alcoholics, antidysrythmics

TETRACYCLINE (cont.)Interactions

Drug: digoxinantacids, iron, and zinc, oral contraceptives, lithium levels

Lab: potassium level Food: Dairy products

(milk, cheese)

High Risk Populations

teratogenic effects children less than

8 should not use due to discoloration of permanent teeth

TETRACYCLINENursing Process

Assess vital signs and urine output-report abnormal findings,

check lab results especially renal and liver function

obtain a Hx of dietary intake and drugs client is currently taking.

Interventions: administer tetracycline 1hr

before or 2 hrs after meals monitor lab values for liver

and kidney function record VS and urine output.

Client Education Storage of

tetracycline expiration date teratogenic effects discoloration of

permanent teeth in children <8, advise

AMINOGLYCOSIDEIndications for Use

Gram-negative bacteria can cause serious infections. Treats PID, effective against methicillian-

resistant and staphylococcus

infections

DRUG Gentamicin

Sulfate (Garamycin)

AMINOGLYCOSIDE (cont.)Side Effects

Tremors, numbness, rash, muscle cramps or

weakness, anorexia, visual disturbance AR: Oliguria,

uticaria, palpations, superinfection LIFE

THREAT: nephrotoxicity, agranulocytosis,

neuromuscular block, ototoxicity and liver

damage

ContraindicationsSever renal disease,

hypersensitivity, lactation, pregnancy,

Caution: renal disease, heart failure,

myasthenia gravis, parkinsonism, older adults, neonates

AMINOGLYCOSIDE (cont.)Interactions

Drug: Increase risk of ototoxicity with loop diuretics, increase risk of nephrotoxicity with amphotericin B, furosemide, and vancomycin

Lab: Increase BUN, serum AST, ALT, LDH, bilirubin, creatinine, decrease serum potassium and magnesium

High Risk Populations Nephrotoxicity is

dependent on drug dose, renal function, and age. Age: young and older clients should be assessed for signs of toxicity: hearing, balance, urinary output.

AMINOGLYCOSIDENursing Process

Assess VS and urine outpute and compare these results w/ future VS and urine output, assess renal function, liver function and electrolytes, assess Hx of renal or hearing disorders.

Interventions: Send sample to lab for C&S, monitor I&O, urinalysis may be ordered daily, check for hearing loss, monitor VS, and note if body temperature has decreased.

Client Education Unless fluids are

restricted, encourage client to increase fluid intake.

Instruct client never to take leftover antibiotics.

FLOUROQUINOLONEIndications for Use

Respiratory infections

(moderate to severe), renal and

bone infections

DRUG Levofloxacin

(Levaquin)

FLOUROQUINOLONE (cont.)

Side EffectsAbdominal cramps, HA,

fatigue, dizziness, restlessness, flushing,

rash, flatulence, photosensitivity, tinnitus

AR: Steven-Johnson syndrome,

encephalopathy, dysrythmias, seizures, psuedo-membranous

colitis.

ContraindicationsSevere renal disease,

hypersensitivity to other quinolones,

breastfeeding, pregnancy Caution:

renal disorders, children <14 or older

adults, patients taking, theophylline, seizures

FLOUROQUINOLONE (cont.)

Interactions Drug: Increase effect

of oral hypoglycemics, theophylline, and caffeine, decrease drug absorpotion with antacids and iron

Lab: Increase AST and ALT

High Risk Populations

Diabetes Mellitus: monitor blood sugar. Levofloxacin can increase effects of oral hypoglycemics.

FLOUROQUINOLONENursing Process

Record VS and I&O-compare w/ future results, assess lab results for renal function, obtain a drug and diet Hx

Interventions: Send specimen to lab for C&S, monitor I&O, recort VS and report abnormal findings, check lab results for liver dysfunction, administer meds 2hrs before or after antacids and iron products, take w/ a full glass of water, if GI distress occurs, take w/ food, check serum theophylline levels, monitor blood sugar

Client Education Teach client to

drink at least 6 to 8 glasses of fluid daily. Encourage client to avoid caffeinated products.

SULFONAMIDEIndications for Use

To treat urinary tract infection, otitis media, bronchitis, pneumonia, pneumocystis carinii; infection, rheumatic fever, burns

DRUG sulfamethoxazole-

Trimethroprim/TMP-SMZ (Bactrim), (Septra)

SULFONAMIDE (cont.)Side Effects

SE: Anorexia, rash, stomatitis, fatigue,

depression, headache, vertigo, photosensitivity. AR:

LIFE THREAT: leukopenia, thrombocytopenia,

increased bone marrow depression, hemolytic

anemia, aplastic anemia, agranulocytosis,Stevens-Johnson syndrome, renal

failure

ContraindicationsSevere renal or hepatic disease,

hypersensitivity to sulfonamides

SULFONAMIDE (cont.)Interactions

Drug: Increase anticoagulant effect with warfarin, increase hypoglycemic effect with oral hypoglycemic drugs

Lab: May increase BUN, serum creatinine, AST, ALT, and ALP

High Risk Populations

Clients with AIDS are more susceptible to TMP-SMZ toxicity

SULFONAMIDENursing Process

Assess client’s renal function, obtain medical and drug Hx, determine if client is hypersensitive to sulfonamides, assess baseline lab results especially CBC.

Interventions: Administer w/ a full glass of water, monitor VS, Observe client for hematologic reactions that may lead to life-threatening anemias, check for S&S of superinfection.

Client Education Instruct client to take several

quarts of fluid daily, advise pregnant clients not to take during the last 3 months of pregnancy, inform client not to take antacids w/ sulfonamides, warn client who has an allergy to one sulfonamide that all sulfonamide preparations should be avoided, with health care provider’s approval, because of the possibility of cross sensitivity.

ANTIVIRALIndications for UseThere are groups of

antiviral drugs effective against various viruses such as influenza A and

B, herpes species, cytomegalovirus (CMV),

and human immunodeficiency virus

(HIV).

DRUG Purine Nucleosides-

Acyclovir Sodium (Zovirax)

Systemic Non HIV- amantadine HCI (Symmetrel)

Neuraminidase Inhibitors- oseltamivir phosphate (Tamiflu)

ANTIVIRAL (cont.)Side Effects

HA, tremors, lethargy, rash, pruritus, increased bleeding time, phlebitis at IV site AR: Uticaria, anemia, gingival hyperplasia. LIFE THREAT:

neuropathy, seizures, nephrotoxicity (large doses),

bone marrow depression, thrombocytopenia,

leukopenia, granulocytopenia

ContraindicationsHypersensitivity, severe renal or hepatic disease.

Caution: electrolyte imbalance, nursing

mothers, young children

ANTIVIRAL (cont.)Interactions

Drug: Increase nephro-neurotoxicity with aminoglycosides, probenecid, and interferon

Lab: May increase AST, ALT, and BUN

High Risk Populations

Cervical cancer is more prevelant in women with genital herpes, these women should have a PAP smear twice a year

ANTIVIRALNursing Process

Obtain a medical Hx from client of any serious renal or hepatic disease, determine baseline VS and a CBC to use for comparison of future results, assess baseline lab results for future comparison, assess baseline VS and urine output.

Interventions: Check clients CBC, record urine output, note VS especially BP, observe for S&S of SE, check for superinfection, dilute IV drug and administer over 60 min, never give acyclovir as a bolus (IV push).

Client Education Advise client to maintain

adequate fluid intake to ensure sufficient hydration for drug therapy and increase urine output, instruct client w/ genital herpes to avoid spreading infection by practicing sexual abstinence or by using condoms, Direct clients taking zidovudine to have blood cell count monitored.

Quiz Time !!!!!

REFERENCES

Ryan, K. J., Ray, C. G., (2004). Medical Microbiology: An introduction to infectious disease (4th ed).

New York, NY. McGraw-Hill, Unit 1.