Mephyton
phytonadione
(fye-toe-na-dye-one) phytonadione,Mephyton
(trade name),vitamin K
(trade name)Classification
Therapeutic: antidotesPharmacologic: fat soluble vitamins
Indications
- Excessive doses of oral anticoagulants,
- Salicylates,
- Certain anti-infective agents,
- Nutritional deficiencies,
- Prolonged total parenteral nutrition.
Action
Therapeutic effects
Pharmacokinetics
Time/action profile
| ROUTE | ONSET | PEAK† | DURATION‡ |
|---|---|---|---|
| PO | 6–12 hr | unknown | unknown |
| Subcut | 1–2 hr | 3–6 hr | 12–14 hr |
| IV | 1–2 hr | 3–6 hr | 12 hr |
Contraindications/Precautions
Adverse Reactions/Side Effects
Gastrointestinal
- gastric upset
- unusual taste
Dermatologic
- flushing
- rash
- urticaria
Hematologic
- hemolytic anemia
Local
- erythema
- pain at injection site
- swelling
Miscellaneous
- allergic reactions
- hyperbilirubinemia (large doses in very premature infants)
- kernicterus
Interactions
Drug-Drug interaction
Large doses will counteract the effect of warfarin.Large doses of salicylates or broad-spectrum anti-infectives may ↑ vitamin K requirements.Bile acid sequestrants, mineral oil, and sucralfate may ↓ vitamin K absorption from the GI tract.Route/Dosage
IV use of phytonadione should be reserved for patients with serious or life-threatening bleeding and elevated INR. Oral route is preferred in patients with elevated INRs and no serious or life-threatening bleeding. IM route should generally be avoided because of risk of hematoma formationTreatment of Hypoprothrombinemia due to Vitamin K Deficiency (from factors other than warfarin)
Vitamin K Deficiency (Supratherapeutic INR) Secondary to Warfarin
Prevention of Hypoprothrombinemia during Total Parenteral Nutrition
Prevention of Hemorrhagic Disease of Newborn
Treatment of Hemorrhagic Disease of Newborn
Availability (generic available)
Nursing implications
Nursing assessment
- Monitor for frank and occult bleeding (guaiac stools, Hematest urine, and emesis). Monitor pulse and BP frequently; notify health care professional immediately if symptoms of internal bleeding or hypovolemic shock develop. Inform all personnel of patient’s bleeding tendency to prevent further trauma. Apply pressure to all venipuncture sites for at least 5 min; avoid unnecessary IM injections.
- Pediatric: Monitor for side effects and adverse reactions. Children may be especially sensitive to the effects and side effects of vitamin K. Neonates, especially premature neonates, may be more sensitive than older children.
- Lab Test Considerations: Monitor prothrombin time (PT) prior to and throughout vitamin K therapy to determine response to and need for further therapy.
Potential Nursing Diagnoses
Imbalanced nutrition: less than body requirements (Indications)Ineffective tissue perfusion (Indications)
Implementation
- Do not confuse Mephyton (phytonadione) with methadone.
- The parenteral route is preferred for phytonadione therapy but, because of severe, potentially fatal hypersensitivity reactions, IV vitamin K is not recommended.
- Administration of whole blood or plasma may also be required in severe bleeding because of the delayed onset of this medication.
- Phytonadione is an antidote for warfarin overdose but does not counteract the anticoagulant activity of heparin.
Intravenous Administration
- pH: 3.5–7.0.
- Intermittent Infusion: Diluent: Dilute in 0.9% NaCl, D5W, or D5/0.9% NaCl.
- Rate: Administer over 30–60 min. Rate should not exceed 1 mg/min.
- Y-Site Compatibility: alfentanil, amikacin, aminophylline, ascorbic acid, atracurium, atropine, azathioprine, aztreonam, benztropine, bumetanide, buprenorphine, butorphanol, calcium chloride, calcium gluconate, cefazolin, cefoperazone, cefotaxime, cefotetan, cefoxitin, ceftazidime, ceftriaxone, cefuroxime, chloramphenicol, chlorpromazine, clindamycin, cyanocobalamin, cyclosporine, dexamethasone sodium phosphate, digoxin, diphenhydramine, dopamine, doxycycline, enalaprilat, ephedrine, epinephrine, epoetin alfa, erythromycin, esmolol, famotidine, fentanyl, fluconazole, folic acid, furosemide, ganciclovir, gentamicin, glycopyrronate, heparin, hydrocortisone sodium succinate, imipenem/cilastatin, indomethacin, insulin, isoproterenol, ketorolac, labetalol, lidocaine, mannitol, meperidine, metaraminol, methoxamine, methyldopate, metoclopramide, metoprolol, metronidazole, midazolam, morphine, multivitamins, nafcillin, nalbuphine, naloxone, nitroglycerin, nitroprusside, norepinephrine, ondansetron, oxacillin, oxytocin, papaverine, penicillin G, pentamidine, pentazocine, pentobarbital, phenobarbital, phentolamine, phenylephrine, potassium chloride, procainamide, prochlorperazine, propranolol, pyridoxime, ranitidine, sodium bicarbonate, streptokinase, succinylcholine, sufentanil, theophylline, thiamine, ticarcillin/clavulanate, tobramycin, tolazoline, trimetaphan, vancomycin, vasopressin, verapamil, vitamin B complex with C
- Y-Site Incompatibility: dantrolene, diazepam, diazoxide, magnesium sulfate, phenytoin, trimethoprim/sulfamethoxazole
Patient/Family Teaching
- Instruct patient to take phytonadione as directed. Take missed doses as soon as remembered unless almost time for next dose. Notify health care professional of missed doses.
- Cooking does not destroy substantial amounts of vitamin K. Patient should not drastically alter diet while taking vitamin K. See for foods high in vitamin K.
- Caution patient to avoid IM injections and activities leading to injury. Use a soft toothbrush, do not floss, and shave with an electric razor until coagulation defect is corrected.
- Advise patient to report any symptoms of unusual bleeding or bruising (bleeding gums; nosebleed; black, tarry stools; hematuria; excessive menstrual flow).
- Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications and alcohol.
- Advise patient to inform health care professional of medication regimen prior to treatment or surgery.
- Advise patient to carry identification at all times describing disease process.
- Emphasize the importance of frequent lab tests to monitor coagulation factors.
Evaluation/Desired Outcomes
- Prevention of spontaneous bleeding or cessation of bleeding in patients with hypoprothrombinemia secondary to impaired intestinal absorption or oral anticoagulant, salicylate, or anti-infective therapy.
- Prevention of hemorrhagic disease in the newborn.