Breastfeeding your baby can bring many benefits and help you create a bond with your new baby but for some, breastfeeding may not come easy and can be a painful and stressful experience. Both you and your baby benefit from breastfeeding but it can be hard work with too many considerations. It is important for breastfeeding mothers to inform their child’s paediatrician about all of the medications they are taking, including herbal products. Not all drugs are present in clinically significant amounts in human milk or pose a risk to the infant. Certain classes of drugs can be problematic, either because of accumulation in breast milk or due to their effects on the nursing infant or mother. The most common products of concern include pain medications, antidepressants, and drugs to treat substance/alcohol abuse or smoking abandonment.

Phenazopyridine is an azo dye. Other azo dyes, which were previously used in textiles, 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. Phenazopyridine is used as a local anesthetic in urinary tract disorders to relieve pain of lower urinary-tract irritation, as in cystitis, urethritis or prostatitis. It only provides symptomatic relief, appropriate treatment of the cause of pain should be initiated and phenazopyridine should be discontinued when symptoms are controlled.

Phenazopyridine is administered in form of oral tablets. Metabolism of phenazopyridine probably occurs in the liver; one of the metabolites is acetaminophen. It exerts an analgesic or local anaesthetic effect on the mucosa of the urinary tract. It possesses no antibacterial actions. The drug is rapidly excreted by the kidneys, with much of an oral dose excreted unchanged in the urine. The pharmacokinetic disposition of phenazopyridine has not been fully established. Trace amounts of the drug are believed to cross the placenta and to enter the brain.

Phenazopyridine – Side Effects, Pregnancy and Lactation

Side Effects of Phenazopyridine

Serious side effects have been reported with phenazopyridine.  See the phenazopyridine precautions section.  Common side effects of phenazopyridine include the following:

• Phenazopyridine produces a vivid color change in urine, typically from Red-orange to brown colored urine (this is not harmful, but care should be taken to avoid staining clothing or other items)
• Headache
• Itching
• Dizziness
• Stomach upset (taking with or after meals may reduce stomach upset).
• Phenazopyridine should be avoided by people with glucose-6-phosphate dehydrogenase deficiency, because it can cause hemolysis (destruction of red blood cells) due to oxidative stress.
• It has been reported to cause methemoglobinemia after overdose and even normal doses.
• Also been reported to cause sulfhemoglobinemia.

Tell your doctor if you experience serious side effects of Phenazopyridine including:

• pale skin
• fever
• confusion
• weakness
• jaundice (yellowing of your skin or eyes)
• urinating less than usual or not at all
• drowsiness
• mood changes
• increased thirst
• loss of appetite
• nausea
• vomiting
• swelling
• weight gain
• shortness of breath
• Blue or purple coloring on your skin.

Phenazopyridine and Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant. The FDA categorizes medications based on safety for use during pregnancy.  Five categories – A, B, C, D, and X are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Phenazopyridine falls into category B. This means that the medication has shown no adverse events in animal models. There are no well-done studies that have been done in humans with phenazopyridine. In animal studies, pregnant animals were given this medication, and the babies did not show any medical issues related to this medication.

Phenazopyridine and Lactation

Nevertheless, phenazopyridine should be used during pregnancy only if clearly needed. It is not known whether phenazopyridine is excreted in human milk. The safety of phenazopyridine is not established in infants or during breastfeeding. And as many medications can cross human milk and hence have possibilities for serious adverse reactions in nursing infants with the use of them. Cases of acquired methemoglobinemia, sulfhemoglobinemia, and hemolytic anaemia in infants after phenazopyridine ingestion have been reported. Phenazopyridine and its metabolites (i.e., aniline) may have the potential to produce these medical conditions.

Therefore, it is prudent to avoid phenazopyridine use while breastfeeding, especially with an infant < 1 month of age or with G-6-PD deficiency. Tell your doctor if you are breastfeeding or planning to breastfeed. So a choice should be made whether to stop nursing or stop the use of this medication.  Your doctor and you will decide if the benefits outweigh the risk of using phenazopyridine.