C H A P T E R 5 2
Drugs affecting the urinary tract and the bladder
827
bladder wall. Pentosan polysulfate sodium (
Elmiron
) is
used to coat or adhere to the bladder mucosal wall and
protect it from irritation related to solutes in urine. It is
not available in New Zealand.
Therapeutic actions and indications
Pentosan polysulfate sodium, available for oral
administration, is a heparin-like compound that has
anticoagulant and fibrinolytic effects. This drug adheres
to the bladder wall mucosal membrane and acts as a
buffer to control cell permeability, preventing irritating
solutes in the urine from reaching the bladder wall cells
(see Figure 52.1). It is used specifically to decrease the
pain and discomfort associated with
interstitial cystitis
,
a chronic inflammation of the interstitial connective
tissue of the bladder that may extend into deeper tissue.
See Table 52.4.
Pharmacokinetics
After oral administration, very little of this drug is
absorbed (3%). It is distributed to the GI tract, liver,
spleen, skin, bone marrow and periosteum. It under-
goes metabolism in the liver and spleen and is excreted
in urine. It has a half-life of 4.8 hours. It is not known
whether the drug crosses the placenta or enters breast
milk due to the lack of adequate studies of the effects
of the drug during pregnancy or breastfeeding; caution
should be used if the drug is needed during pregnancy or
breastfeeding.
Contraindications and cautions
Pentosan should not be used with any condition that
involves an increased risk of bleeding (surgery, preg-
nancy, anticoagulation, haemophilia)
because of its
heparin-like effects.
It is also contraindicated in the
presence of a history of heparin-induced thrombocyto-
penia,
which could recur with use of this drug.
Caution should be used in individuals with hepatic
or sphenic dysfunction,
which could be affected by
the heparin-like actions of the drug
, and in pregnant
or breastfeeding women
because of the potential for
adverse effects on the fetus or neonate.
Adverse effects
Adverse effects associated with pentosan use include
bleeding that may progress to haemorrhage (related to
the drug’s heparin effects), headache, alopecia (seen
with heparin-type drugs) and GI disturbances related to
local irritation of the GI tract with administration.
Clinically important drug–drug interactions
There is a potential for increased bleeding risks if
this drug is combined with anticoagulants, aspirin or
non-steroidal anti-inflammatory drugs (NSAIDs). If such
a combination is used, the person should be monitored
very closely for any signs of bleeding, and appropriate
dose adjustments should be made to the anticoagulants,
aspirin or NSAID.
TABLE 52.4
DRUGS IN FOCUS Other drugs affecting the urinary tract and bladder
Drug name
Dosage/route
Usual indications
Bladder protectant
pentosan polysulfate
sodium (Elmiron)
100 mg PO t.d.s
Relief of bladder pain or discomfort
associated with interstitial cystitis
Prototype summary: Pentosan polysulfate
sodium
Indications:
Relief of bladder pain associated with
interstitial cystitis.
Actions:
Adheres to the bladder wall mucosal
membrane and acts as a buffer to control cell
permeability, preventing irritating solutes in the
urine from reaching the bladder wall cells.
Pharmacokinetics:
Route
Onset
Oral
Varies
T
1/2
:
4.8 hours; metabolised in the liver and spleen
and excreted in urine.
Adverse effects:
Bleeding, headache, alopecia, GI
disturbances.
Care considerations for
people receiving a bladder protectant
Assessment: History and examination
■
■
Assess for
contraindications or cautions
: history of
allergy to these drugs
to prevent hypersensitivity
reactions
or renal insufficiency,
which could
interfere with excretion of the drug
; history
of bleeding abnormalities, splenic disorders or
hepatic dysfunction,
which could be exacerbated
by the heparin-like effect
s; and current status
of pregnancy and breastfeeding,
which require
cautious use of this drug.
