Ppt chapter 42

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins

Chapter 42

Drugs Treating Urinary Tract Infections

Chapter 42

Drugs Treating Urinary Tract Infections


QuestionQuestion

• What population is at greatest risk of having a UTI?

– A. Women of childbearing age and children

– B. Elderly and postmenopausal women

– C. Males and elderly

– D. Women aged 15 to 65 years


AnswerAnswer

• B. Elderly and postmenopausal women

• Rationale: Elderly and postmenopausal women produce less mucin and therefore are at a higher risk for UTI.


Physiology Physiology

• Normally, several host defenses protect a person from UTI.

• The urinary bladder is lined with a mucin layer that acts as a barrier against bacterial invasion.

• This layer also secretes protective substances that eventually become part of the mucin layer.

• Elderly and postmenopausal women produce less mucin and therefore are at a higher risk for UTI.

• Another host defense is the washout phenomenon.

• Immune mechanisms provide another host defense.


Pathophysiology Pathophysiology

• Urinary tract infections are generally classified as complicated or uncomplicated.

• UTIs can be acute, recurrent, or chronic.

• Asymptomatic bacteriuria: no symptoms of UTI

• Cystitis: infection of the lower urinary tract

• Urethritis: associated with sexual transmitted disease

• Prostatitis: associated with urethritis or cystitis

• Acute pyelonephritis: infection of the kidneys and renal pelvis


Urinary TractUrinary Tract


QuestionQuestion

• Asymptomatic bacteriuria is common during pregnancy.

– A. True

– B. False


AnswerAnswer

• A. True

• Rationale: Asymptomatic bacteriuria is common during pregnancy. It is important to identify in pregnant women because it increases the risk of pyelonephritis during the second and third trimesters. Additionally, untreated UTI is associated with an increased risk of miscarriage.


Diagnosis of UTI Diagnosis of UTI • Diagnosis of UTI is frequently based on the patient’s

subjective description of symptoms and a positive urine dipstick test.

• The dipstick test is recommended for nonpregnant women at low risk for recurrent infection and without symptoms suggesting other problems, such as vaginitis.

• A urinalysis (UA) is required for women who are pregnant or over the age of 55, men with urinary symptoms, and patients with recurrent symptoms.

• A successful UA requires a midstream or clean-catch urine specimen.

• When obtaining urine for a UA from a catheterized patient, the urine must be withdrawn from the proximal port on the catheter tubing and not from the urine collection bag.


Sulfonamides Sulfonamides

• Sulfonamides have been the mainstay of treatment for UTIs for many years.

• Unfortunately, the incidence of sulfonamide-resistant bacteria has steadily increased.

• Prototype drug: sulfamethoxazole/trimethoprim (SMZ-TMP) (Bactrim DS, Cotrimoxazole, Septra DS)


Sulfamethoxazole-Trimethoprim: Core Drug Knowledge Sulfamethoxazole-Trimethoprim: Core Drug Knowledge

• Pharmacotherapeutics

– Uncomplicated UTIs and systemic infections

• Pharmacokinetics

– Administered: oral. Metabolism: liver. Peak: 4 hours.

• Pharmacodynamics

– Interferes with the synthesis of folic acid (folate)


Sulfamethoxazole-Trimethoprim: Core Drug Knowledge (cont.)Sulfamethoxazole-Trimethoprim: Core Drug Knowledge (cont.)

• Contraindications and precautions

– Hypersensitivity, deficiency of G6PD or folate

• Adverse effects

– Nausea, vomiting, diarrhea, hematologic effects (e.g., anemia), allergic reactions, and crystalluria

• Drug interactions

– Interacts with other protein-bound drugs


Sulfamethoxazole-Trimethoprim: Core Patient Variables Sulfamethoxazole-Trimethoprim: Core Patient Variables

• Health status

– Assess for contraindications to drug therapy.

• Life span and gender

– Evaluate pregnancy or breast-feeding status.

• Lifestyle, diet, and habits

– Ask about dietary intake and alcohol use.

• Environment

– Photosensitivity may occur.


Sulfamethoxazole-Trimethoprim: Nursing Diagnoses and Outcomes Sulfamethoxazole-Trimethoprim: Nursing Diagnoses and Outcomes

• Pain related to altered comfort level (nausea, vomiting, diarrhea, dizziness, or headache) from adverse effects of SMZ-TMP

– Desired outcome: The patient will develop strategies to cope with pain and take the drug as directed for the full course of therapy.

• Risk for Injury related to drug-induced hypersensitivity reactions, liver or kidney dysfunction, or blood dyscrasias

– Desired outcome: By the end of therapy, the patient will be free from avoidable drug therapy–related injuries and infection.


Sulfamethoxazole-Trimethoprim: Nursing Diagnoses and Outcomes (cont.)Sulfamethoxazole-Trimethoprim: Nursing Diagnoses and Outcomes (cont.)

• Risk for Impaired Tissue Integrity related to drug-induced photosensitivity

– Desired outcome: The patient will take measures to protect his or her skin from prolonged sun exposure.


Sulfamethoxazole-Trimethoprim: Planning and InterventionsSulfamethoxazole-Trimethoprim: Planning and Interventions

• Maximizing therapeutic effects

– Administer SMZ-TMP 1 hour before or 2 hours after a meal with a full glass of water to enhance the absorption of the drug.

• Minimizing adverse effects

– Administer SMZ-TMP with a full glass of water.

– Fluid intake should increase by 1.5 L/day.


Sulfamethoxazole-Trimethoprim: Teaching, Assessment, and EvaluationsSulfamethoxazole-Trimethoprim: Teaching, Assessment, and Evaluations

• Patient and family education

– Teach patients the optimal way to take SMZ-TMP.

– Teach interventions to decrease the risk for adverse effects.

• Ongoing assessment and evaluation

– Monitor patients for signs of hematologic dysfunction, such as sore throat, fever, bruising, or bleeding.


QuestionQuestion

• SMZ-TMP should be given with food to increase absorption.

– A. True

– B. False


AnswerAnswer

• B. False

• Rationale: Administer SMZ-TMP 1 hour before or 2 hours after a meal with a full glass of water to enhance the absorption of the drug.


Urinary Tract Antiseptics Urinary Tract Antiseptics

• Urinary tract antiseptics are drugs that work by local action because high serum levels are not achievable.

• Methenamine (Hiprex, Urex)

– Indicated for suppressing or eliminating bacteriuria (bacteria in urine) associated with chronic cystitis and other chronic UTIs

– Contraindicated in patients with hepatic dysfunction


Urinary Tract Antiseptics (cont.)Urinary Tract Antiseptics (cont.)

• Nitrofurantoin (Furadantin, Macrodantin, Macrobid)

– Is presumed to interfere with several bacterial enzyme systems

– Although nitrofurantoin has a broad spectrum of activity, it is not an effective systemic drug because it is rapidly excreted by the kidneys.

– Contraindicated in patients with renal impairment


Urinary Tract Analgesic Urinary Tract Analgesic

• Phenazopyridine (Pyridium) is used frequently for UTIs but does not itself have any antibacterial activity.

• It is excreted in the urine, where it exerts a topical analgesic effect.

• It is indicated for the symptomatic relief of pain, burning, frequency, and urgency.

• The precise mechanism of action is not known.

• Contraindicated for patients with known hypersensitivity or renal insufficiency.

• Adverse reactions include headache, rash, pruritus, and GI disturbances.


QuestionQuestion

• It is important to teach the patient receiving phenazopyridine that his or her urine will appear

– A. Orange

– B. Red

– C. Dark brown

– D. Both A and B


AnswerAnswer

• D. Both A and B

• Rationale: Phenazopyridine is an azo dye, which colors the patient’s urine orange or red. It is important to inform the patient to expect this change in urine color.

Ppt chapter 42

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