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Konakion Side Effects

Generic name: phytonadione

Medically reviewed by Last updated on Oct 22, 2023.

Note: This document contains side effect information about phytonadione. Some dosage forms listed on this page may not apply to the brand name Konakion.

Applies to phytonadione: oral capsule, oral tablet. Other dosage forms:

Serious side effects of Konakion

Along with its needed effects, phytonadione (the active ingredient contained in Konakion) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking phytonadione:

Incidence not known

Other side effects of Konakion

Some side effects of phytonadione may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

For Healthcare Professionals

Applies to phytonadione: compounding powder, injectable solution, oral tablet.


Rare (less than 0.1%): Injection site reactions (inflammation, atrophy, necrosis)

Very rare (less than 0.01%): Venous irritation or phlebitis (IV route)

Frequency not reported: Pain, swelling, and tenderness at the injection site[Ref]


Rare (less than 0.1%): Rapid and weak pulse, hypotension, cyanosis

Very rare (less than 0.01%): Facial flushing

Postmarketing reports: Tachycardia, flushing[Ref]


Very rare (less than 0.01%): Anaphylactoid reactions (IV route)

Frequency not reported: Allergic sensitivity, anaphylaxis

Postmarketing reports: Fatal hypersensitivity reaction[Ref]

Fatalities and other severe reactions have occurred during or immediately after the parenteral administration of phytonadione. The majority of these reactions have occurred with intravenous administration. These reactions resemble hypersensitivity or anaphylaxis and include shock and cardiac or respiratory arrest. Feelings of uneasiness, flushing, diaphoresis, chest pain, tachycardia, cyanosis, weakness, and dyspnea may precede the cardiopulmonary event. These severe reactions are more likely with, but are not limited to, rapid infusions of undiluted drug.[Ref]


Gastrointestinal side effects have rarely included 'peculiar' sensations of taste.


Rare (less than 0.1%): Dyspnea[Ref]


Frequency not reported: Death (IV and IM routes)[Ref]


Uncommon (0.1% to 1%): Erythematous, indurated, pruritic plaques

Rare (less than 0.1%): Profuse sweating, scleroderma-like lesions,

Very rare (less than 0.01%): Sweating

Frequency not reported: Erythema perstans-like lesions[Ref]

Nervous system

Rare (less than 0.1%): Dizziness

Very rare (less than 0.01%): Unusual taste

Postmarketing reports: Dysgeusia[Ref]


Rare (less than 0.1%): Hyperbilirubinemia

Frequency not reported: Jaundice in newborns[Ref]

Hyperbilirubinemia occurred primarily with doses above those recommended.[Ref]


Frequency not reported: Hemolysis in newborns[Ref]


The most common adverse events were dermatologic and injection site reactions.[Ref]


1. (2022) "Product Information. Vitamin K (phytonadione)." Apothecon Inc

2. Cerner Multum, Inc. "UK Summary of Product Characteristics."

3. Cerner Multum, Inc. "Australian Product Information."

4. (2001) "Product Information. Mephyton (phytonadione)." Merck & Co., Inc

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.