Antibiotics For UTI: Urinary Tract Infection

antibiotics for uti

Antibiotics For UTI

Antibiotics for UTI include many types and generic names. The most commonly used antibiotics for UTI are: penicillins, Sulfonamides, Cephalosporins and Fluoroquinolones.

Urinary tract infections also known as UTIs are a very common problem encountered by everyone in their lifetime, especially women. It was evidenced that one in three women will have been treated for at least one urinary tract infection (UTI) by the age of 26 years. Urinary tract infections (UTI) are prevalent in women because of the anatomy of their genitourinary system: unlike men, women have a short urethra and this results in shortening the distance a bacteria must cross to reach the bladder. It has been shown that Escherichia coli (E.Coli) was the bacterium responsible for more than 80% of urinary tract infections (UTI) seen by doctors in outpatients.

urethra men women
Difference In urinary system between men and women

Antibiotics for UTI

1. Penicillins as Antibiotics for UTI

Penicillins were widely used as standard antibiotics for UTI especially UTI caused by enteric pathogens. This class of antibiotics has a broad spectrum but resistance to E.Coli is increasingly growing in the recent years.

Types of penicillin antibiotics for UTI are Ampicillin, Amoxicillin and Amoxicillin Calvulanate (Augmentin)

As the majority of antibiotics, penicillins have some adverse effects that include :

  • Gastrointestinal disturbance: diarrhea, nausea and vomiting.
  • Hematology: risk for bleeding, anemia.
  • Integumentary: urticaria, rash.

2. Sulfonamides as Antibiotics for UTI

Sulfonamides are inexpensive antibiotics for UTI. They have a bacteriostatic action by inhibition of p-Aminobenzoic acid, necessary for the synthesis of the bacterial folic acid.

The most commonly used Sulfonamide drug as an antibiotic for UTI is Trimethoprim-sulfamethoxazole (Bactrim, Septra) which is a combination of Sulfametoxazole and Trimethoprim. This medication is also known as TMP-SMX.

With regards to their adverse reactions, sulfonamides can cause gastrointestinal disturbances like nausea, vomiting or abdominal pain; and CNS symptoms like headache, dizziness and insomnia.

3. Cephalosporins as Antibiotics for UTI

Cephalosporins are divided into four different generations according to their spectrum of activity against Gram negative bacteria. They have some chemical and pharmacological properties similar to these of penicillin.

Cephalosporins have a broad spectrum against Gram+ and Gram- bacteria, what made them a treatment of choice in UTIs resistant to Amoxicillin and Trimethoprim-sulfamethoxazole. But, this tend to change due to overuse of cephalosporins and development of resistance.

Types of Cephalosporins used as antibiotics for UTI:

  • First generation: cefadroxil (Duricef), cefazolin (Ancef), cephalexin (Keflex), cephradine (Velosef)
  • Second generation: cefaclor (Ceclor), cefamandole (Mandol), cefotetan (Cefotan), cefoxitin (Mefoxin), cefuroxime (Zinacef, Ceftin)
  • Third generation: cefdinir (Omnicef), cefixime (Suprax), cefoperazone (Cefobid), ceftazidime (Fortaz), ceftriaxone (Rocephin)
  • Fourth generation: cefepime (Maxipime)

The adverse effects of cephalosporins are as follow:

  • GI: diarrhea, nausea, vomiting, abdominal pain
  • CNS: headache, dizziness, weakness
  • Hematology: leukopenia, thrombocytopenia, agranulocytosis, anemia
  • Integumentary: rash, urticaria, dermatitis
  • Genitourinary (GU): proteinuria, vaginitis, candidiasis, nephrotoxicity

4. Fluoroquinolones as Antibiotics for UTI

Quinolones are synthetic, bactericidal antibacterial agents with broad-spectrum activity used in the treatment of urinary tract infections caused by most organisms. Exhibit bactericidal properties by interfering with the duplication of DNA.

Types of Fluoroquinolones used as antibiotics for UTI:

  • Ciprofloxacin (Cipro)
  • Enoxacin (Penetrex)
  • Gatifloxacin (Tequin)
  • Levofloxacin (Levaquin)
  • Norfloxacin (Noroxin)
  • Ofloxacin (Floxin)

Adverse reactions related to Fluoroquinolones:

  • GI: nausea, vomiting, diarrhea
  • CNS: dizziness, drowsiness, headache, restlessness
  • Integumentary: rash, pruritus, urticaria, photosensitivity


Leave a Reply