Prescription medication · Vitamin K Supplement
phytonadione
Also sold as Vitamin K1, Mephyton. This medicine treats bleeding problems caused by low vitamin K levels.
Data updated 2026-05-15
- 8,078
- FDA reportsLightly reported
- 1
- InteractionFew interactions
- 1
- Recall record
What the data shows
phytonadione (Vitamin K1) is a prescription Vitamin K Supplement, reported less often than most tracked drugs (8,078 FDA reports), with 1 documented drug interaction.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
phytonadione (Vitamin K1) is a prescription Vitamin K Supplement. This medicine treats bleeding problems caused by low vitamin K levels.
Phytonadione is a vitamin K supplement. It helps your blood clot properly.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Generic Price
$12.59/unit
Generic Available
Yes (15 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
This medicine treats bleeding problems caused by low vitamin K levels.
Common side effects
No common side effects listed.
Key warnings
This medicine can cause severe reactions, including death, if given intravenously (into a vein) or intramuscularly (into a muscle).
The sections below are summarized in plain English from phytonadione's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Phytonadione provides vitamin K1, which is needed to make certain clotting factors in your blood. These clotting factors help stop bleeding. By increasing these factors, phytonadione helps your blood clot normally.
How to Take It
Phytonadione is usually given as an injection by a healthcare provider. It can be injected under the skin, into a muscle, or into a vein. The dose depends on your condition and how you respond to the medicine. If injected into a vein, it should be given very slowly.
This is a plain-language summary of phytonadione's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
It is not known if phytonadione can harm an unborn baby. Talk to your doctor if you are pregnant or breastfeeding.
This is a plain-language summary of phytonadione's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
Since phytonadione is usually given by a healthcare provider, you are not likely to miss a dose. If you are giving yourself the injections, call your doctor if you miss a dose.
This is a plain-language summary of phytonadione's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store at room temperature (68 to 77°F) and protect from light. Keep the ampules in the carton until you are ready to use them.
Side Effects (from patient reports)
Based on 8,078 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for phytonadione, by number of reports
- Feeling sick to your stomach
Feeling sick to your stomach
630 reports
- Throwing up
Throwing up
533 reports
- Feeling very tired
Feeling very tired
523 reports
- Difficulty breathing
Difficulty breathing
486 reports
- Blood infection
Blood infection
446 reports
- Loose stools
Loose stools
436 reports
- Stomach pain
Stomach pain
428 reports
- Difficulty passing stools
Difficulty passing stools
405 reports
- Pain in your head
Pain in your head
372 reports
- Swollen stomach
Swollen stomach
368 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for phytonadione each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where phytonadione sits
phytonadione has more FDA adverse-event reports than 35% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is phytonadione; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 8,078 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 1999–2025.
Total Reports
8,078
Reports Mentioning Death
1,508
18.7% of reports — not proof of cause
Hospitalization Reports
3,758
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 2 | NAUSEA | 630 |
| 3 | VOMITING | 533 |
| 4 | FATIGUE | 523 |
| 5 | DYSPNOEA | 486 |
| 7 | SEPSIS | 446 |
| 8 | DIARRHOEA | 436 |
| 9 | ABDOMINAL PAIN | 428 |
| 10 | CONSTIPATION | 405 |
| 11 | HEADACHE | 372 |
| 12 | ABDOMINAL DISTENSION | 368 |
| 13 | CONDITION AGGRAVATED | 364 |
| 14 | PYREXIA | 346 |
| 15 | ANAEMIA | 344 |
| 16 | ASCITES | 337 |
| 17 | GENERAL PHYSICAL HEALTH DETERIORATION | 314 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
This medicine can cause severe reactions, including death, if given intravenously (into a vein) or intramuscularly (into a muscle). These reactions can resemble an allergic reaction, with shock and cardiac or respiratory arrest. Intravenous and intramuscular routes should only be used if subcutaneous injection is not possible.
Known Drug Interactions
If relatively large doses have been employed, it may be necessary when reinstituting anticoagulant therapy to use somewhat larger doses of the prothrombin-depressing anticoagulant, or to use one which acts on a different principle, such as heparin sodium.
Mechanism: Vitamin K helps blood clot, but heparin works to thin the blood using a different process that Vitamin K does not block.
What to do: Your doctor may use heparin if you need to thin your blood after taking Vitamin K.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
Common Questions
What is phytonadione used for?
How is phytonadione given?
What should I do if I experience side effects?
Can I take phytonadione if I am pregnant?
How quickly does phytonadione work?
Will I need blood tests while taking this medicine?
Can phytonadione interact with other medicines?
What if the injection site is painful?
Is phytonadione the same as vitamin K?
What should I avoid while taking phytonadione?
Does phytonadione interact with other medications?
What drug class is phytonadione?
Is phytonadione safe during pregnancy?
Has phytonadione been recalled?
Active Recalls
Failed Stability Specifications: Observed OOS results: eg results for colour index
Cipla Limited
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Medication Guides
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What the FDA Data Shows for phytonadione
The FDA label for phytonadione (sold under brand names such as Vitamin K1, Mephyton) classifies it as a prescription-only medication in the Vitamin K Supplement class. This medicine treats bleeding problems caused by low vitamin K levels. Labeling covers dosing, contraindications, and monitoring requirements derived from clinical trials.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 8,078 voluntary reports. The database also lists 1 documented drug interaction derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $12.59.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 1 recall record on file), and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: May 30, 2019
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages