Urinary Antiseptics Organisms Escherichia coli Proteus Pseudomonas species

Urinary Antiseptics

Organisms Ø Ø Ø Ø Escherichia coli Proteus Pseudomonas species streptococci Klebsiella Enterococcus Staphylococcus epidermidis

Introduction n n 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

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

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 8095% Widely distributed in body fluids and tissues. Plasma Half life 3 -10 hrs permitting once daily dosing.

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 Therapeutic Uses: n n Many gm –ve organisms. Lower urinary tract infections.

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

Nitrofurantion Bacteriostatic and bactericidal for many Gm +ive and Gm –ive bacteria 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.

Mechanism of Action: Complex 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.

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 (but not proteus or pseudomonas) • Uncomplicated urinary tract infections • Daily dose for adults is 100 mg orally 6 hourly with food or milk

n It is desirable to keep urinary p. H 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 G 6 PD deficiency Acute pneumonitis (fever, chills, leucopenia) Resistance • Resistance emerges slowly • No cross resistance between Nitrofurantion and other antimicrobial agents

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

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

Ø Ø Taken orally excreted unchanged in urine where these drugs are bactericidal for some Gm –ive bacteria when p. H is less than 5. 5 Acidifying agents (Ascorbic acid 4 -12 gm / day) may be needed to lower urinary p. H below 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

Therapeutic uses and status: Not a primary drug, effective for chronic suppressive treatment. Effective against E. coli, S. aureus, S epidermidis and common gram negative bacteria.

Phenazopyridine n n n Phenazopyridine hydrochloride has an analgesic action in urinary tract’ Dysuria Frequency Burning Urgency

Treatment of urinary tract infections n n n 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.

n n n Bacteriological investigations---direct choice of drug Upper UTI dose of the drug is as for systemic infections If recurrences are frequent, chronic suppressive treatment is needed.

n Sulfonamides, Cotrimoxazole, Quinolones, Ampicillin, Cloxacillin, Piperacillin, cephalosporins, gentamicin, Chloramphenicol, Tetracyclines.