Phenazopyridine is a chemical that, when released into the urine, has a local analgesic effect. It is often used to relieve pain, irritation, discomfort, or urgency caused by urinary tract infections, surgery, or injury to the urinary tract. Phenazopyridine was discovered by Bernhard Joos, founder of Cilag.
Video Phenazopyridine
Medical use
Phenazopyridine is prescribed for local analgesic effects on the urinary tract. Sometimes used in conjunction with antibiotics or other anti-infective drugs early in treatment to help relieve symptoms directly. Phenazopyridine does not treat infections or injuries; only used to relieve symptoms. It is recommended that it be used no more than the first two days of antibacterial treatment because longer treatment may mask the symptoms.
Phenazopyridine is also prescribed for other cases that require relief from irritation or discomfort during urination. For example, it is often prescribed after the use of an inside Foley catheter, an endoscopic procedure (cystoscopy), or after surgery of the urethra, prostate, or bladder that may cause irritation of the urinary tract epithelial layer.
The American Urological Association has recommended the use of phenazopyridine as a first-line treatment for interstitial cystitis.
It is not used to treat infections and may mask untreated UTI symptoms. It provides symptomatic relief during UTI, after surgery, or injury to the urinary tract. UTI therapy should be limited to 1-2 days. Long-term use of phenazopyridine may mask symptoms.
Maps Phenazopyridine
Side effects
Phenazopyridine produces vivid color changes in the urine, usually to a dark orange to a reddish color. These effects are common and harmless, and indeed are the main indicators of the presence of drugs in the body. Phenazopyridine users are warned not to wear contact lenses, since phenazopyridine has been known to permanently discolor contact lenses and fabrics. Some people may misunderstand that this indicates the presence of blood in the urine.
Phenazopyridine can also cause headaches, abdominal pain (especially when not taken with food), or dizziness. Less often it can cause pigment changes in the skin or eyes, to a visible yellowish color. This is due to the suppressed excretion through the kidneys that cause the buildup of drugs in the skin, and usually indicates the need to discontinue use. Other side effects include fever, confusion, shortness of breath, skin rashes, and swelling of the face, fingers, feet, or legs. Long-term use can cause yellowing of the nails.
Phenazopyridine should be avoided by people with a deficiency of glucose-6-phosphate dehydrogenase, because it can cause hemolysis (destruction of red blood cells) due to oxidative stress. It has been reported to cause methemoglobinemia after an overdose and even a normal dose. At least in one case the patient had a low rate of reduction of pre-existing methemoglobin, which tended to affect this condition. It has also been reported to cause sulfhemoglobinemia.
Phenazopyridine is azo dye. Other azo dyes, previously used in textile, printing, and plastic manufacturing, have been implicated as carcinogens that can cause bladder cancer. While phenazopyridine has never been shown to cause cancer in humans, evidence from animal models suggests that it is potentially carcinogenic.
Pregnancy
This drug is a B pregnancy category. This means that the drug does not show any adverse effects on the animal model, but no human trials are performed. It is not known whether phenazopyridine is excreted in breast milk.
Pharmacokinetics
The complete pharmacokinetic properties of phenazopyridine have not been determined. This has been widely studied on animal models, but they may not be very representative of humans. The mouse model showed half-life to 7.35 hours, and 40% metabolized liver (by the liver).
Action mechanism
The mechanism of action of Phenazopyridine is not well known, and only basic information about its interaction with the body is available. It is known that chemicals have a direct topical analgesic effect on the mucosal lining of the urinary tract. This is quickly excreted by the kidneys directly into the urine. Hydroxylation is the main form of metabolism in humans, and azo bonds are usually not cleaved. At the order of 65% of the oral dose will be excreted directly to urine chemically unchanged.
Brand name
In addition to its generic form, phenazopyridine is distributed under the following brand names:
References
External links
- Information on phenazopyridine from the US National Library of Medicine
- Interstitial Cystitis Association
- American Urological Association
Source of the article : Wikipedia