phytonadione
Phytonadione is a vitamin K supplement that helps prevent bleeding in adults with certain blood clotting conditions or those taking medications like warfarin. It comes as a tablet that's taken by mouth, and your prescriber will recommend a dose based on your lab tests. Side effects from the tablet are rare. There's also an injection form commonly given to newborn babies to prevent internal bleeding since they have low vitamin K levels at birth.
What is Phytonadione?
What is Phytonadione used for?
Treatment of blood clotting problems caused by:
- Blood thinners like warfarin
- Antibiotics
- Conditions that affect how your body absorbs or makes vitamin K (e.g. jaundice, celiac disease, ulcerative colitis)
- Medications that interfere with vitamin K, like aspirin.
How Phytonadione works
Phytonadione is a vitamin K supplement. Vitamin K is an essential vitamin your liver needs to make clotting factors — proteins that help your blood clot and prevent excessive bleeding.
Drug facts
Side effects of Phytonadione
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
See Risks and Warnings
Less Common Side Effects
The following side effects are reported from the intravenous (IV) injection form, which is given in the hospital.
- Allergic reactions
- Flushing sensation
- Unusual taste
- Dizziness
- Fast or weak pulse
- Sweating
- Low blood pressure
- Trouble breathing
- Blue skin (cyanosis)
- High bilirubin levels in newborn babies
The following Phytonadione side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
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Pros and cons of Phytonadione
Pros
- The only oral pill to prevent bleeding caused by warfarin
- Sometimes only 1 or 2 doses are needed
- Dose can be adjusted based on how you respond
Cons
- Takes several hours to start working, so not a good option for emergencies or major bleeding
- Usually needs repeat blood tests to check if it's working
- Can cause too much clotting if not dosed carefully
Pharmacist tips for Phytonadione
- Phytonadione tablets take 6 to 10 hours to work, so it might not be fast enough for serious bleeding. If you have major bleeding, get medical help right away.
- Phytonadione breaks down quickly when exposed to light. Always keep the tablets protected from light by storing them in their original, closed vial until you’re ready to take them.
- You’ll need blood tests after taking phytonadione because it works differently for everyone. Make sure to get blood tests and follow up with your prescriber.
- If you have severe liver or gallbladder problems, you might need to take phytonadione with bile salts to help your body absorb it properly.
- Phytonadione can interact with blood thinners, temporarily making them work less well. If this happens, your prescriber might need to change your blood thinner dose or recommend a different one, like heparin.
- Phytonadione is a higher strength and prescribed for specific blood clotting problems, compared to OTC vitamin K supplements. Talk to your prescriber before taking any vitamin K supplements to make sure they are safe for you.
Common questions about Phytonadione
Yes. Newborns are born with low levels of vitamin K, so it’s recommended that they receive a vitamin K injection in the muscle shortly after birth. Speak to your OB-GYN provider if you have questions about this medication.
Phytonadione is a man-made form of vitamin K, specifically vitamin K1. It's available as a prescription medication used to treat or prevent low vitamin K levels and related blood clotting problems. There's also vitamin K supplements available over the counter (OTC) which might contain both vitamin K1 and vitamin K2. Before taking any vitamin K supplements, talk to a healthcare professional (HCP) to make sure they’re safe for you.
Phytonadione is found in breast milk, but it’s not known how it affects the breastfed baby or milk production. Speak to your prescriber about the risks and benefits of taking this medication while nursing.
It can be in certain situations. Phytonadione is used to reverse the effects of blood thinners like warfarin when they cause excessive bleeding or if there’s a risk of bleeding due to a high INR (a measure of blood clotting). But it works slowly, so it’s not a quick solution for life-threatening bleeding. In emergencies, other treatments like plasma or Kcentra can be given with phytonadione.
Pretty slowly. Phytonadione tablets usually start working within 6 to 10 hours. But if your lab work doesn’t show enough improvement within 12 to 48 hours, your prescriber might recommend you take another dose.
The brand name for phytonadione tablets, Mephyton, has been discontinued. Only the generic version is now available.
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Risks and warnings for Phytonadione
Phytonadione can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Taking too much phytonadione
If you’re taking phytonadione to treat blood thinning caused by anticoagulant medications like warfarin, you might be at risk of the same clotting problems that led to starting the anticoagulant in the first place, such as atrial fibrillation, pulmonary embolism (PE), or deep vein thrombosis (DVT). Phytonadione isn't a clotting agent, but taking too much can bring back conditions that raise your risk of dangerous blood clots. It’s important to take the lowest dose needed. Your prescriber will check your blood tests regularly to make sure your dose is right for your condition.
Phytonadione dosage
Typical dosage for Phytonadione
The typical starting dose is 2.5 mg to 10 mg taken by mouth as a single dose, but it can go up to 25 mg in some cases. In rare situations, 50 mg might be needed. Your prescriber will decide how much and how often you should take phytonadione based on your lab tests and your overall health.
Phytonadione is also available as an injection form, which is usually given in the hospital or clinic.
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