Metanx Warnings and Precautions
To determine whether Metanx is suitable for you, make sure your healthcare provider is aware of any other medical conditions you have, such as anemia, Leber's disease, or a seizure disorder. Other warnings and precautions with Metanx include possible drug interactions and allergic reactions. Also, make sure to tell your healthcare provider if you are pregnant or breastfeeding.
What Should I Tell My Healthcare Provider?You should talk with your healthcare provider prior to taking Metanx® if you have:
- Low vitamin B12 blood levels
- Plans to have coronary stent (a procedure to open blocked or narrowed heart arteries)
- Leber's disease (a rare genetic eye condition)
- Polycythemia vera (an abnormal increase in red blood cells)
- A seizure disorder
- Any allergies, including to foods, dyes, or preservatives.
Also, let your healthcare provider know if you are:
- Pregnant or thinking of becoming pregnant
You should also tell your healthcare provider about all other medications you are taking, including prescription and nonprescription medicines, vitamins, and herbal supplements.
Specific Precautions and Warnings With MetanxSome warnings and precautions to be aware of prior to taking this product include the following:
- Metanx contains a form of folic acid. Folic acid can mask pernicious anemia, which is a decrease in red blood cells that occurs when the body cannot absorb vitamin B12 properly. This means it will be more difficult to determine if you have pernicious anemia from blood tests. Your healthcare provider may test you for pernicious anemia before you start taking Metanx.
- Do not take large doses of vitamins (megadoses or megavitamins) with Metanx unless your healthcare provider tells you otherwise.
- Using a combination of vitamins (vitamin B12, vitamin B6, and folic acid) similar to those found in Metanx during and after coronary stenting may increase the risk for renarrowing of the heart arteries (called "restenosis"). In general, this combination of vitamins is not recommended for use in people receiving coronary stents.
- Metanx contains a form of vitamin B12. Vitamin B12 has been associated with a rare skin condition, known as rosacea fulminans, which causes severe skin redness, bumps, and pimples. The condition may continue for months after vitamin B12 is stopped, and may require treatment.
- Vitamin B12 intake can expose undiagnosed polycythemia vera, a condition associated with an abnormal increase in red blood cells. Symptoms of this condition may include but are not limited to:
- Difficulty breathing, especially when lying down
- Itchiness, especially after a hot bath or shower
- Skin redness
- Numbness, tingling, or burning.
- Vitamin B12 may damage the eye nerve (optic nerve) in people with a genetic eye condition called Leber's disease. Because Metanx contains a form of vitamin B12, you should discuss this with your healthcare provider if you have Leber's disease.
- Treating megaloblastic anemia (an anemia characterized by larger than normal red blood cells) with vitamin B12 (one of the vitamins found in Metanx) could result in dangerously low blood potassium levels (hypokalemia) and gout in certain people.
- Skin reactions, such as acne, allergic reactions, redness, itching, and sun sensitivity, have been reported with vitamin B6 and folic acid use. Because Metanx contains forms of these vitamins, you should report any such reactions to your healthcare provider.
- High doses of folic acid may increase the risk for seizures in people with seizure disorders. Metanx contains a form of folic acid. Therefore, let your healthcare provider know if you have a seizure disorder before you take this medication.
- Metanx may react with several other medications (see Metanx Drug Interactions).
- It is unknown if Metanx is safe for pregnant women. Talk to your healthcare provider about the risks and benefits of using Metanx during pregnancy (see Metanx and Pregnancy).
- It is unknown if Metanx passes through breast milk. Therefore, if you are breastfeeding or plan to start, discuss this with your healthcare provider prior to taking the drug (see Metanx and Breastfeeding).