Antibiotics PCN Danita Dee Narciso Pharm D 1 2 Objectives - - PowerPoint PPT Presentation

UH Hilo School of Nursing NURS 203 General Pharmacology

Antibiotics

PCN

Danita Dee Narciso Pharm D

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Objectives

 Recognize the signs and symptoms of

infection

 Become familiar with antibiotics that are

commonly used and recognize areas of potential practical conflicts

 Recognize antibiotics that have interactions

with psychoactive medications or illnesses

 Learn how to monitor for and adjust for

changes in drug levels due to interactions with antibiotics

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Introduction

 Signs and symptoms of infection

 Fever  WBC increases

 Normal = 4,000 – 10,000 cells/mm3  Increases in lymphocytes ~ TB, viral, or fungal

infections

 Increases in monocytes ~ TB or lymphoma  Increases in eosinophills ~ Allergy

 Local signs

 Pain, swelling, redness, tenderness, purulent

discharge

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Fever (pyrexia)

 Normal – 98.0-98.6º F (36.7-37ºC)

 Rectal - 1ºF or 0.6ºC higher  Axillary - 1ºF or 0.6ºC lower

 Hyperpyrexia  Hypothermia  Other Causes

 Trauma  Malignancy  Infarctions  Blood disorders  Various drugs  Immune disorders

 False positives  False negatives

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Drug induced fever

 Beta lactams  Anticonvulsants  Allopurinol (Zyloprim) – Gout  Hydralazine – Blood pressure  Nitrofurantoin (Macrobid) – UTI  Sulfonamides  Phenothiazines  Methyldopa – Blood pressure in pregnancy

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Drug induced fever

 Sulfonamides

 Sulfamethoxazole  Diuretics  Anticonvulsants  Celecoxib

(Celebrex)

 Sumatriptan

(Imitrex)

 Phenothiazines

 Promethazine  Chlorpromazine

(Thorazine)

 Thioridazine

(Mellaril)

 Prochlorperazine

(Compazine)

False positives, false negatives???

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Penicillin

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Terms

 Bactericidal  Bacteriostatic  Beta-lactam antibiotics  Beta-lactamases (penicillinase)  Penicillin binding proteins (PBPs)  Peptidoglycan  Transpeptidases

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Penicillin – a beta-lactam antibiotic

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Penicillin (PCN)

 Bactericidal vs bacteriostatic  MOA

 Bind to PBPs, inhibit the reaction (transpeptidase

reaction) that cross links the peptidoglycan chain on the bacterial cell wall, and activate autolytic enzymes

 Time dependent killing

 The bacteria’s defense

 Penicillinase (beta-lactamases)  Changes in PBPs

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Penicillins

 Natural pcn

 Penicillin G…  Penicillin VK

 Mild to moderate infection without

bacteremia of the skin and respiratory tract

 Gonorrhea – IM  Syphilis - IM  Neurosyphilis – IM/IV  Pharyngitis  URI

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Penicillins

 Penicillinase resistant

 Oxacillin  Dicloxacillin  Nafcillin

 MSSA infections  Erysipelas  Skin abscess  CNS infections – PCN can penetrate

inflamed meninges

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Penicillins

 Aminopenicillins

 Amoxacillin  Ampicillin

 May be used in combination with a beta-lactamase

inhibitor

 Augmentin – amoxicillin and clavulanic acid  Unasyn – ampicillin and sulbactam

 Sinus infection  Dental prophylaxis  ENT and genitourinary infection  Hpylori  UTI  Meningitis

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Penicillins

 Extended spectrum

(Carboxypenicillins/ureidopenicillins)

 Ticarcillin  Piperacillin

 Used in combination with a beta-lactamase

inhibitor

 Zosyn – piperacillin and tazobactam  Timentin – ticarcillin and clavulanic acid

 IV – UTI, systemic infections, complicated

abdominal infections, etc…

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PCN - Kinetics

 Absorption

 Oral depends on pH

 Distribution

 Lungs, liver, kidneys, muscle, bone, placenta, and

urine

 Metabolism

 Liver – limited and converted to inactive

metabolites

 Excretion

 Mostly (60%) unchanged in the urine – monitor

renal function

 Bile – nafcillin and oxacillin

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Adverse drug reactions

 GI disturbances

 Nausea, diarrhea, black hairy tongue (ampicillin),

 Dermatologic

 Rash and redness

 CNS

 Agitation, anxiety, seizure, confusion, and

behavioral changes

 Psudomembranous cholitis – extended spectrum

and aminoPCNs

 Liver toxicity - oxacillin  Be aware when a patient has recently started a

penicillin

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Drug-drug interactions

 Probenecid

 Increase PCN concentrations

 Methotrexate

 PCNs reduce tubular secretion

 Tetracycline

 May reduce the effectiveness of PCNs

 Chloramphenicol

 May reduce the effectiveness of PCNs

 Neomycin

 Decreases the absorption of some PCNs

 Hormonal contraception

 Effectiveness is reduced with the use of some PCNs

 Anticoagulants

 PCNs may increase the bleeding risk

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Allergy

 Allergy is the most common ADR related

to penicillins and can range from itching, fever, and rash to nephritis and anaphylaxis

 An allergic reaction may occur 1 – 2

weeks after an injection (serum sickness)

 Oral allergy may present as

 Tongue swelling  Nausea, vomiting, or diarrhea

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Resistance

(Saving our big guns for big bugs)

 Identify the organism  Empiric therapy in some cases

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PCN and UTI

 Signs and symptoms

 General

 Lower UTI

 Painful urination, urgency, frequency, nocturia, blood in

urine, and suprapubic heaviness

 Upper UTI

 Flank pain, fever, nausea, vomiting, and muscle weakness

 Elderly

 Altered mental status, change in eating habits, or GI

symptoms

 Indwelling catheters and neurologic disorders

 Usually develop upper UTI with bacteremia due to the

absence of symptoms

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Questions

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