Nitrofurantoin is an antibiotic designed to treat urinary tract infections. It is also used to treat a bladder infection called cystitis. Some common brand names for antibiotics are Furadantin, Macrodantin, and Macrobid. Does nitrofurantoin affect birth control? While this antibiotic may have some benefits and is not known to reduce the effectiveness of contraceptives specifically, it is not recommended to be taken with it. For those on contraceptives who are also taking nitrofurantoin, it may be of concern if vomiting or diarrhea occurs. This could mean the effectiveness of contraceptives may be damaged.
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Common side effects of nitrofurantoin
There are many common side effects when taking nitrofurantoin. The likelihood of experiencing these issues increases in older adults. The most common side effect is diarrhea.
Possible side effects include:
- Appetite loss
- Abdominal pain
- Abnormal weakness or loss of energy
- Rapid and involuntary eye movements
- Hair loss
- Yellow-brown urine discoloration
- Salivary gland inflammation
- Sore throat
- Itchy skin
- Joint pain
- Muscle pain
- Rigors (shivering chills)
Serious side effects of nitrofurantoin
In addition to the common side effects, there are many more serious side effects of nitrofurantoin. Luckily, these side effects are much more rarely experienced but can lead to severe conditions like hemolytic anemia, peripheral neuropathy, or pancreatitis.
Some of the more severe side effects are severe abdominal pain and watery or bloody diarrhea or dark urine that persist after stopping the medication. You may also experience weakness, numbness, or pain in the limbs, such as the hands, feet, arms, and legs. Others have experienced redness or swelling in the lower jaw and some skin peeling or rashes in other body areas.
In some cases, people also reported visual disturbances due to taking nitrofurantoin. These may include blurred vision, vision loss, or severe pain behind the eyes. Other reported problems include increased pressure on the skull, which may lead to vision problems, ear ringing, nausea, dizziness, and severe headaches.
In very severe cases, side effects may include jaundice and other signs of issues with the functioning of the liver or pancreas. Some may also experience reduced red blood cells, white blood cells, and blood platelets. For those that are pregnant and give birth, they may find bulging soft spots on their newborn’s skull.
In addition to the long list of possible side effects of nitrofurantoin, there are also some possible allergic reactions.
Some clinical trials have been done for the drug Macrobid – one of the name-brand antibiotics for nitrofurantoin. Although allergic reactions occurred in only under 1% of those studied, there were some alarming reactions. Reactions included itchy skin, hives, swelling of the phase, swelling of the throat, burning eyes, skin pain, peeling skin, and a painful reddish-purple-colored rash with blistering and peeling skin.
How long do nitrofurantoin side effects last?
The longevity of side effects experienced while on nitrofurantoin varies from person to person. Often, they go away during the treatment, but this isn’t always the case. Side effects that persist after this period are a significant cause for concern. For example, long-term use of the drug can lead to drug-induced lung disease. This is a rare occurrence but has happened in patients who were taking the drug for at least six months. Typically, this goes away naturally after the drug has stopped being taken, but all long-term takers of nitrofurantoin should be carefully monitored even after they have stopped.
Read also: How Does Zoloft Affect Birth Control?
Nitrofurantoin contraindications & warnings
Those who stop taking nitrofurantoin are not known to experience any withdrawal symptoms. However, it isn’t recommended to stop taking the drug prematurely. Doing so will not allow for the full effects of the drugs and may increase the risk of the infection recurring.
Taking too much of the drug may have very harmful side effects. Vomiting, in this case, is very likely, and a healthcare provider or poison control should be notified immediately. Some additional rules to follow are to discard any unused liquids after 30 days do not exceed 400 mg/day. Most recommended daily dose ages are much smaller than that amount. Custom doses may be prescribed by healthcare providers for children under 12 years old. Most people 12 years old and older will be prescribed between 50 and 100 mg per day or every six hours. Other 100 mg extended-release capsules may also be prescribed.
Many restrictions are also essential to keep in mind. If the patient had previously been struggling with another medical condition, the side effects of the drug could worsen. This includes those with compromised kidneys, impaired liver function, hepatitis, breastfeeding mothers, diabetes mellitus, anemia, and those with lung or breathing problems. Those with specific conditions such as peripheral neuropathy or those who have what is called glucose-6-phosphate dehydrogenase (G6PD) deficiency are more susceptible to experiencing bad reactions. Those above age 65 are asked to be extra cautious because a higher likelihood of decreased kidney function may worsen side effects.
Nitrofurantoin during pregnancy
Although there is not a lot of information out yet showing the drug effects on pregnancy, some studies suggest evidence links craniosynostosis to fetal exposure to nitrofurantoin and drugs with similar chemical structures. It is strongly recommended not to take the drug, especially during the first trimester, as it is associated with congenital disabilities.
There is a period when the drug can remain mostly safe for pregnant women. That is between the end of the first trimester and before the 38th week of gestation. After 38 weeks, or during labor and delivery, pregnant women should no longer take nitrofurantoin.
Additionally, research shows that women who are breastfeeding may be able to take the drug safely. A small quantity can pass through the breast milk and will likely have little side effects if the infant is older than eight days old and has no G6PD deficiency.
Five main interactions can be experienced while taking nitrofurantoin. These include interactions with antacids, anesthetics, probenecid or sulfinpyrazone, live cholera vaccine or live typhoid vaccine, and fluconazole.
Antacids often contain magnesium trisilicate. This could decrease the absorption of nitrofurantoin, making it less effective. Anesthetics are particularly dangerous when taken with the drug. They often include lidocaine, articaine, mepivacaine, and ropivacaine. The combination of those with the contents of nitrofurantoin can increase the risk of methemoglobinemia, which leaves those infected with a blood disorder where too little oxygen is delivered to a patient’s cells.
Harmful drug interactions may also occur. Probenecid, or sulfinpyrazone, is a drug that is commonly used to treat gout. When taken with nitrofurantoin, the level of the drug may be increased, causing toxic side effects. Fluconazole taken with nitrofurantoin can also increase the likelihood of toxicity in the lungs.
Does nitrofurantoin affect birth control?
Just as nitrofurantoin can be tricky when taken while pregnant, this is also the case while on birth control. Does nitrofurantoin affect birth control? The drug should not impact the efficacy of oral contraceptives unless the nitrofurantoin is causing vomiting or diarrhea or longer than 24 hours while taking the birth control drug. If this happens, a doctor should be notified immediately. Aside from this issue, there is no known specific reaction for the antibiotic with birth control pills.
How to avoid nitrofurantoin side effects
Experiencing side effects of nitrofurantoin can be severe. It is best to take preventive measures so they are less likely to occur. Some ideas to remember are to tell a doctor immediately if you are taking any other medications or at-home remedies alongside nitrofurantoin, take the course of the antibiotic with food, and avoid antacids containing magnesium trisilicate.
When to see a Doctor
Remember to contact a doctor if anything feels out of the ordinary. Doctors should also be notified of patients’ complete medical history and any current drugs or conditions that they might have. This can help prevent unintentional harmful side effects and allow medical professionals to catch issues earlier. It could save a life.
If you are taking birth control and are experiencing issues you think may be a reason for concern, such as vomiting or diarrhea for an extended period, seeing a doctor will allow them to offer additional advice and alternative contraceptive measures.
A common occurrence with those trying to treat their UTIs is first trying at-home remedies and over-the-counter medication. This history should also be discussed with a doctor before taking nitrofurantoin. This also includes information about the patient’s health history, such as kidney disease, anemia, diabetes, electrolyte imbalance, vitamin B deficiency, glucose-6-phosphate dehydrogenase (G6PD) deficiency, or other diseases.
Frequently Asked Questions
Studies have been done to look at the effects of nitrofurantoin on sperm mobility. One study showed sperm motility and fertilizing capacity were decreased in nitrofurantoin because of reduced metabolism. Another study showed that antibiotics can cause sperm immobilization.
Taking nitrofurantoin long-term could affect fertility levels. However, most of these side effects should go away within three months after the drug has stopped being taken. A doctor should be consulted to find a new antibiotic that won’t impact sperm mobility.
Unfortunately, nitrofurantoin can cause a long list of side effects. Some of the most common side effects include changes in facial or skin color, chest pain, chills, cough, fever, general feeling of discomfort or illness, hives, hoarseness, itching, joint or muscle pain, shortness of breath, skin rash, sudden trouble in swallowing or breathing, swelling of the face, mouth, hands, or feet, and troubled breathing. There is also a long list of less common and rare side effects.
It is also important to note that some medications and health complications could cause adverse side effects when taken alongside nitrofurantoin.
Although nitrofurantoin is known to decrease fertility, it is still possible to get pregnant while taking the antibiotic. If you become pregnant while taking nitrofurantoin, you should call a doctor immediately. Nitrofurantoin may cause problems in newborns after delivery if the drug is taken during the last month of pregnancy.
With a long list of possible side effects from taking nitrofurantoin, there is also a list of what to avoid. Some things to avoid include:
- Magnesium-containing antacids
- Certain live vaccines
- Certain lab tests
- Certain foods
Magnesium-containing antacids and probenecid, used to treat gout, can reduce the effectiveness of nitrofurantoin. Certain vaccines may also become less effective if the antibiotic is taken simultaneously.
When taking tests that require urine testing, nitrofurantoin may cause a false-positive reading for glucose. This false information may lead healthcare workers to believe you have another serious health condition that isn’t present, such as diabetes or kidney problems.
Taking methotrexate alongside nitrofurantoin has one of the most dangerous side effects. Taking the two together could lead to potentially severe reactions in the lungs.
Lastly, some foods and drinks may worsen UTI symptoms. These include drinks containing large amounts of caffeine, artificial sweeteners, juices, citrus fruits, spicy foods, and acidic foods. These foods and drinks and drinks should be avoided for the best results.
If the antibiotics affect your mood, St. John’s Wort is safe to take to decrease feelings such as anxiety or depression.
Not all antibiotics are designed the same. However, there are some precautions to take when combining birth control pills and urinary tract infection antibiotics. Certain urinary tract drugs and antibiotics used for treating UTIs can make birth control less effective and lead to an unwanted pregnancy. Some specific UTI antibiotics to avoid while taking birth control are Rifampin, Griseofulvin, and some anticonvulsants. These antibiotics can interfere with the absorption of hormones in birth control capsules. Remain cautious and talk to a doctor before taking any other type of antibiotic while on birth control.
The majority of antibiotics don’t have an impact on contraception. However, there are new findings that show types of antibiotics that interact with hormonal contraception may make it less effective, such as rifampicin-like antibiotics. These are enzyme-inducing and may prevent the full effects of hormonal contraception. Rifamycin, like rifampin, rifabutin, and rifapentin, are commonly used to treat bacterial infections. The liver breaks down your hormonal birth control much faster when rifamycin antibiotics are taken, making the birth control less effective.
Nitrofurantoin is not known to affect the efficacy of oral contraceptives. The only known complication the antibiotic could have with the effectiveness of oral contraceptives is side effects of the antibiotic are causing vomiting or diarrhea longer than 24 hours. If this is the case, talk to a doctor about alternatives that you can take.