Urinary antiseptics pharmacology

1. Urinary Antiseptics
By=Dr.Ishfaq Ahmad

3. Treatment of urinary
tract infections
 Most UTIs are caused by gram
negative bacteria specially
coliforms.
 Acute infections are self limiting,
high urine flow rate with frequent
bladder voiding.
 Upper UTIs require more aggressive
and longer treatment.

4. Organisms
 Escherichia coli (80%)
 Staphylococcus saprophyticus
 Proteus
 Pseudomonas species
 Enterococcus
 Staphylococcus epidermidis

5. Introduction
 Oral agents have antibacterial
activity in urine but have little or no
systemic antibacterial activity
 Usefulness is limited to lower UTI
 Effective antibacterial concentration
reach the renal pelvis and bladder.
 Used in chronic UTI where eradication of
infection by short term systemic
therapy has not been possible

6. Drugs that act as urinary
antiseptics are as
follows:
•Nalidixic Acid & Cinoxacin
•Nitrofurantion
•Methenamine
•Phenazopyridine

7. Nalidixic Acid &
Cinoxacin
Introduction: One of the earlier
quinolones, did not achieve
systemic antibacterial levels
therefore were useful only for
treatment of lower UTI
Pharmacokinetics: Well absorbed
orally. BA 80-95%
Widely distributed in body fluids and
tissues. Plasma Half life 3-10 hrs
permitting once daily dosing.

8.  Oral absorption is impaired by divalent
cations including those in antacids.
 Serum concentration of I/V
administration is equal to orally
administered drug.
 Excretion is renal either GF or Tubular
secretion
MOA inhibit DNA gyrase and topoisomerase
IV
Therapeutic Uses: -
 Many gm –ve organisms.
 Lower urinary tract infections.

9.  Adverse Effects
 GIT irritation
 Glycosurea
 Skin rashes
 Photo sensitization
 Visual disturbances
 CNS stimulation.
 Hepatic failure

10. Nitrofurantion
 Bacteriostatic and bactericidal for
many Gm +ive and Gm –ive bacteria
specially against E.coli
 Second line agent for treatment of UTI
Pharmakokinetics
•Well absorbed orally
•Rapidly metabolized and excreted
through kidneys glomerular
filtration and tubular secretion.
•No systemic antibacterial activity
•Brown discoloration of urine.

11. Mechanism of Action:
•Rapid intracellular
conversion into highly
reactive intermediates by
bacterial reductase
•This intermediate then reacts
non-specifically with many
ribosomal proteins and disrupt
synthesis of proteins, RNA, DNA
and metabolic processes.

12. Anti bacterial spectrum:
 E. coli, enterococci.
 Most species of Proteus and
Pseudomonas, Enterobacter and
Klebsiella are resistant.
Therapeutic Uses: -
•Active against many urinary
tract pathogens
•Daily dose for adults is 100
mg orally 6 hourly with food
or milk

13.  It is desirable to keep urinary pH below
5.5, which greatly enhances drug
activity
Adverse Effects:-
•GIT irritation, anorexia, nausea,
vomiting
•Skin rashes and hypersensitivity
reactions
•Neuropathies
•Hemolysis in patients with G6PD
deficiency
•Acute pneumonitis (fever, chills,
leucopenia)

14. Contraindications
 Pregnant woman
 Individuals with impaired renal
function.
 Children younger than 1 month
of age.

15. Methenamine
 Chemistry:
 It is hexamethylenetetramine.
 The compound decomposes in water to
form formaldehyde which is responsible
for antibacterial activity.
 Acidification of urine is required for
this decomposition.
 Methenamine mandelate is salt of
mendelic acid and methenamine
 Methenamine Hippurate is salt of
huppuric acid and methenamine

16.  Taken orally excreted unchanged
in urine
 bactericidal for some Gm –ive
bacteria when pH is less than 5.5
 Combination with sulfonamide lead
to mutual antagonism.
 Microorganisms such as proteus
that make a strongly alkaline
urine through release of ammonia
from urea are usually resistant

17. Therapeutic uses and status:
 used for chronic
suppressive therapy for
UTIs
 Also used for upper UTI like
pyelonephritis
 Effective against E. coli, S.
aureus, S epidermidis and
common gram negative
bacteria.

18. Phenazopyridine
 Phenazopyridine hydrochloride has
an analgesic action in urinary
tract’
 Dysuria
 Frequency
 Burning
 Urgency