822
P A R T 9
Drugs acting on the renal system
Adverse effects
Adverse effects associated with these drugs include
nausea, vomiting, diarrhoea, anorexia, bladder irrita-
tion and dysuria. Infrequent symptoms include pruritus,
urticaria, headache, dizziness, nervousness and confu-
sion. These effects may result from GI irritation caused
by the agent, which may be somewhat alleviated if the
drug is taken with food, or from a systemic reaction to
the urinary tract irritation.
Clinically important drug–drug interactions
Because these drugs are from several different chemical
classes, the drug–drug interactions that can occur are
very specific to the drug being used. Consult a drug
guide for specific interactions.
Prototype summary: Norfloxacin
Indications:
Treatment of adults with UTIs caused
by susceptible strains of bacteria; uncomplicated
urethral and cervical gonorrhoea; prostatitis caused
by
Escherichia coli
.
Actions:
Interferes with DNA replication in
susceptible Gram-negative bacteria, leading to cell
death.
Pharmacokinetics:
Route Onset
Peak
Duration
Oral
Varies
2–3 hours
12 hours
T
1/2
:
3 to 4.5 hours; metabolised in the liver and
excreted in urine.
Adverse effects:
Headache, dizziness, nausea,
vomiting, dry mouth, fever, rash, photosensitivity.
CRITICAL THINKING SCENARIO
Teaching about cystitis treatment
THE SITUATION
J.K. is a 6-year-old girl with a history of repeated urinary
tract infections (UTIs). She was screened for potential
sexual abuse, which may present as repeated urinary tract
infections, and no evidence of abuse was found. She is
seen today with complaints of dysuria, frequency, urgency
and a low-grade fever. A urine sample is sent for culture
and sensitivity testing. The doctor prescribes hexamine
hippurate (
Hiprex
), 500 mg q.i.d., and refers J.K. and her
mother to the nurse for teaching.
CRITICAL THINKING
What is the best approach for J.K.?
What key teaching points (at least five) should be
emphasised to assist the pharmacological therapy in
treating this infection?
Think about the following points:
what the drug is doing, how it works and how it works
best.
DISCUSSION
Cystitis is very difficult to treat in young girls and can
become a chronic problem. Person and parent education
is very important for blocking the growth of bacteria and
curing the infection. Teaching points should emphasise
activities that will decrease the number of bacteria
introduced into the bladder, acidify the urine to make the
bladder an inhospitable environment for bacterial growth,
and flush the bladder to prevent stagnant urine from
encouraging bacterial growth.
To decrease the number of bacteria introduced into
the bladder, education should cover the following hygiene
measures: Always wipe from front to back and never from
back to front to avoid the introduction of intestinal bacteria
into the urethra; avoid baths, particularly bubble baths,
which facilitate the entry of bacteria into the urethra on the
bubbles; and wear dry, cotton underwear to discourage
bacterial growth.
Education also should stress the importance of
avoiding alkaline ash foods (e.g. citrus fruits, certain
vegetables) and antacids and encouraging foods that
acidify the urine. Cranberry juice is often recommended
as a choice for fruit juice because it helps to prevent the
bacteria from adhering to the bladder wall, which in turn
aids infection prevention. Fluid intake, especially water,
should be encouraged as much as possible to keep the
bladder flushed. Finally, the person should be encouraged
to complete the full course of medication prescribed and
not to stop taking the drug when symptoms disappear.
CARE GUIDE FOR J.K.: URINARY TRACT
ANTI-INFECTIVE HEXAMINE HIPPURATE
Assessment: History and examination
Assess J.K.’s health history, particularly any allergies to
antibacterial medications, and liver or renal dysfunction.
(If J.K. were of childbearing age, you would assess
pregnancy and breastfeeding status.)
Focus the physical examination on the following areas:
Neurological: orientation, reflexes, strength
Skin: colour, texture, oedema
