Pharmacology; A Nursing Approach
The largest number of urinary disorders are caused by urinary tract infections. UTI's may start as a result from an upper UTI such as pyelonephritis, or a lower UTI such as cystitis, urethritis, or prostatitis.
Urinary antiseptics/antiinfectives prevent bacterial growth in kidneys and bladder but is not effective for systemic infections.
Urinary antiseptics have a bacteriostatic (inhibit bacterial growth) effect when given in low dosage. They have a bactericidal effect (kill bacteria when given in higher doses.
Urinary analgesics relieve pain and burning in the urinary tract.
Acute cystitis
- a lower UTI
- occurs in females because of their shorter urethra
- it is more common in women of childbearing age, older women, and young girls.
- commonly caused by E. Coli
- symptoms include pain and burning on urination and urinary frequency and urgency
- urine culture is obtained before the start of any antiinfective/antibiotic therapy
- in male clients a lower UTI is usually prostatitis
Acute Pyelonephritis
- an upper UTI
- commonly seen in women of childbearing age, older women, and young girls
- E.Coli is most common organism
- Symptoms include chills, high fever, flank pain, pain during urination, frequency, urgency, and pyuria
- bacterial count is greater than 100,000bacteria/mL
- in severe cases pt may be hospitalized and receive IV antibiotics
Commonly Used Agents for Treating UTI's
- nitrofurantoin (Macrodantin)
- trimethoprim-sulfamethoxazole ( Bactrim, Septra)
- fluoroquinolones (Cipro)
- oral amoxicillin/clavulanic acid (Augmentin)
- oral third generation cephalosporins
Urinary Antiseptics/Antiinfectives and Antibiotics
Limited to treatment of UTI's. Drug action occurs in the renal tubule and bladder where it is effective in reducing bacterial growth. Urinalysis and C&S is usually performed prior to therapy. The groups are nitrofurantoin, methenamine, trimethoprim, and the fluoroquinolones.
Nitrofurantoin
- Macrodantin
- first prescribed to treat UTI's in 1953
- bacteriostatic or bactericidal depending on drug dosage
- effective against many gram positive and gram negative organisms, especially E.Coli
- used to treat acute and chronic UTI's
- Side Effects: GI disturbances such as anorexia, nausea, vomiting, diarrhea, and abdominal pain. Pulmonary reactions such as dyspnea, chest pain, fever, cough.
Nitrofurantoin Pharmacokinetics
- well absorbed from GI tract
- usually taken with food to decrease GI distress
- decreased absorption occurs when drug is taken with antacid
- rapidly eliminated with normal renal function
- accumulates in serum with urinary dysfunction
Nitrofurantoin Pharmacodynamics
- when given at low dosages for prophylactic use, the drug has a bacteriostatic effect
- high concentrations cause a bactericidal effect
- effective against many gram positive and gram negative organisms
- onset and duration of action are unknown
- peak action occurs 30 minutes after absorption
- if sudden onset of dyspnea, chest pain, cough, fever, and chills develops, the client should contact the PCP, symptoms resolve after discontinuing the drug
Nursing Process
Urinary Antiinfective: Nitrofurantoin
Assessment:
- Obtain a history from client of clinical problems with UTI, incontinence, or other urinary tract disorders
- Check client of reigns and symptoms of UTI: pain or burning sensation on urination, frequency and urgency of urination
- Evaluate complete CBC on clients with long term therapy; monitor regularly
- Check urine culture and sensitivity results
- Assess renal and hepatic function
- Determine urine pH. A pH of 5.5 is desired. However, alkalization of the urine is not recommended.
Nursing Diagnosis:
- Acute pain related to inflammation in the urinary tract
- Risk for infection related to insufficient knowledge to avoid invasion of pathogens
Planning:
- Client will be free of signs and symptoms of UTI within 10 days
Nursing Interventions:
- Monitor client's urinary input and output and urine specific gravity. Careful attention to out put is required when administering urinary aseptics to patients with anuria (no output of urine) and oliguria (low output of urine). Report promptly any urine output decrease.
- Obtain urine culture to identify infecting organism prior to initiation of drug therapy to treat UTI.
- Observe client for side effects and adverse reactions to urinary antiseptic drugs. Peripheral neuropathy (tingling, numbness of extremities) may result from renal insufficiency (inability to excrete drug) or long term use of nitrofurantoin. Peripheral neuropathy may be irreversible.
Client Teaching:
- teach client not to crush tablets or open capsules
- advise client to rinse mouth thoroughly after taking oral nitrofurantoin. Drug can stain teeth.
- Instruct client to avoid antacid as it may interfere with drug absorption.
- Teach client to shake suspension well before administration and protect from freezing.
- Warn client not to drive or operate heavy machinery, drug may cause drowsiness.
- Advise female client to immediately report pregnancy to PCP
Diet:
- Inform patient to increase fluids and take drug with food to minimize GI upset
Side Effects:
- Alert client that urine may turn a harmless brown color
- Encourage client to report any signs of secondary fungal or bacterial infection (superinfection), such as stomatitis anogenital discharge or itching
Methenamine:
- Educate client to drink cranberry juice, eat plums, or take Vitamin C (with approval of health care provider) to keep urine acidic.
Fluoroquinolones:
- Warn client to avoid operating heavy machinery, especially if dizziness is present
- Encourage client to take with food and avoid antacids
- Alert client urine may turn harmless brown color
- Direct client to report signs of superinfection
- Tell client to avoid excessive exposure to light
Evaluation:
- Evaluate the effectiveness of the urinary antiinfectives in alleviating the UTI. Client is free of side effects and adverse reactions to the drug.
Methenamine:
- Hiprex
- produces bactericidal effect when urine pH is less than 5.5
- effective against gram negative and gram positive organisms
- used for chronic UTI's
- should not be taken with sulfonamides, because crystalluria is likely to occur
- absorbed readily from GI tract
- 90% is excreted in the urine unchanged
- urine needs to be acidified for bactericidal action
- cranberry juice, ascorbic acid, and ammonium chloride can be taken to lower urine pH
- Side Effects: GI disturbances, nausea, vomiting, diarrhea. Allergic reactions to the dye in Hiprex. Bladder irritation and crystalluria when taken in large doses.
Trimethoprim and Trimethoprim Sulfamethoxazole:
- Bactrim, Septra
- trimethoprim can be used alone for treatment of UTI but is usually used with a sulfonamide, to prevent the occurrence of trimethoprim resistant organisms
- drug combination produces slow-acting bactericidal effects against gram negative an positive organisms
- used in treatment and prevention of chronic and acute UTI's
- Side Effects: GI symptoms and skin problems (rash and pruritus)
Fluoroquinolones:
- Cipro
- urinary antibacterial effective against lower UTI's
- effective against wide variety of UTI's
- drug dosage should be decreased when renal dysfunction is present
- Side Effects: Nalidixic acid (NegGram) use can have headaches, dizzinesss, syncope, peripheral neuritis, visual disturbances, and rash. Photosensitivity is the most common side effect with fluoroquinolones.
Drug-Drug Interactions
The following drug-drug interactions can occur with the use of urinary antiseptics/antiinfectives:
- Antacids decrease nitrofurantoin absorption
- Sodium Bicarb inhibits the action of methenamine
- Methenamine taken with sulfonamides increases the risk of crystalluria
- Nalidixic acid enhances the effects of warfarin (Coumadin)
- Most urinary antiseptics cause false-positive Clinitest results
Urinary Analgesics
- Phenazopyridine hydrochloride (Pyridium)
- an azo dye
- relieves urinary pain and burning, urgency and frequency
- can cause GI disturbances, hemolytic anemia, nephrotoxicity, and hepatotoxicity
- urine become harmless reddish orange
- can alter glucose urine test so blood glucose should be used instead
Urinary Stimulants
- used when bladder function is decreased or lost due to (1) neurogenic bladder (2)spinal cord injury (3) spinal cord injury
- parasympathomimetic may be given to stimulate urination
- drug of choice is Urecholine
- drug action is to increase muscle tone by increasing tone of detrusor muscle which produces a contraction strong enough to stimulate urination
Urinary Antispasmotics/Antimuscarinics
- used to relieve urinary tract spasms resting from infection or injury
- have direct action on smooth muscle of urinary tract
- DMSO contraindicated for use if pt has GI or urinary obstruction or glaucoma
- antispasmodics have same effects as antimuscarinics (agents that block parasympathetic nerve impulses), parasympatholytics, and anticholinergics
- side effects include: dry mouth, increased heart rate, dizziness, intestinal distention, and constipation
- Detrol is used to control overactive bladder and can decrease urge incontinence
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