Pyridoxine HCl Injection

This product is available solely through our 503B Outsourcing Facility, offering you the highest standards of quality and safety in every purchase. If you do not have an account, please contact us.

See Product Details

Start your order

Product Overview

Vitamin B₆ (pyridoxine) can interact with various medications, and these interactions should be considered when administering pyridoxine HCl Injection. One well-documented interaction is with certain anti-epileptic drugs: high-dose pyridoxine may reduce the plasma levels of phenytoin and phenobarbital by enhancing their hepatic metabolism, potentially diminishing their anticonvulsant efficacy. Concurrent administration of pyridoxine with these medications has been reported to lower their therapeutic levels, so monitoring and dosage adjustments of the anticonvulsant might be required if high-dose vitamin B₆ is given.

Pyridoxine also antagonizes the effects of levodopa when levodopa is used without a dopa-decarboxylase inhibitor (such as carbidopa) . In patients with Parkinson’s disease on levodopa monotherapy, vitamin B₆ supplementation can increase peripheral levodopa metabolism and thus reduce the amount of levodopa reaching the central nervous system, worsening symptom control.^[7] (This interaction is not significant when levodopa is combined with carbidopa, as in standard carbidopa/levodopa therapy, because carbidopa prevents peripheral levodopa breakdown.)

Another notable interaction involves the chemotherapeutic agent altretamine: coadministration of pyridoxine can decrease altretamine’s effectiveness and is generally advised against unless specifically directed.^[7]

Conversely, certain drugs can affect pyridoxine status. Isoniazid (INH), a tuberculosis medication, and hydralazine, used for hypertension, both form complexes with pyridoxal 5′-phosphate or otherwise interfere with vitamin B₆ metabolism, leading to functional vitamin B₆ deficiency. Patients on prolonged INH therapy often receive supplemental pyridoxine to prevent peripheral neuropathy, an adverse effect related to B₆ deficiency.

Other antibiotics such as cycloserine and penicillamine have similar vitamin B₆–antagonizing effects, necessitating supplementation to avert neurological side effects.^[8] It is also known that oral contraceptives may lower pyridoxine levels in some individuals, which could be considered a drug-nutrient interaction of clinical relevance.^[5]

In summary, pyridoxine may decrease the efficacy of certain medications (notably levodopa and some anticonvulsants), and various drugs can in turn precipitate vitamin B₆ deficiency. Clinicians should review the patient’s medication list and use pyridoxine judiciously, adjusting therapy as needed to account for these interactions.

At physiological or moderately elevated doses, pyridoxine is generally well tolerated, and side effects tend to be mild. Because pyridoxine HCl Injection is a water-soluble vitamin preparation, it does not typically cause systemic toxicity at recommended dosages. Commonly reported minor adverse effects include nausea, headache, somnolence (drowsiness), and mild paresthesia (tingling or numbness) in the extremities. Some patients receiving intramuscular injections may experience localized injection site reactions such as pain, redness, or irritation, but serious injection site complications are uncommon. Allergic reactions are rare; however, as with any medication, anaphylactic reactions to pyridoxine injection have been reported in isolated cases of hypersensitive individuals. High-dose or prolonged pyridoxine supplementation can also lead to alterations in other nutrient levels – for example, extended use of large doses has been associated with reduced serum folate concentrations in some reports, which suggests a need to monitor nutritional balance during long-term therapy.^[9]

The most significant side effect of excessive pyridoxine exposure is peripheral neuropathy affecting sensory nerve function. Chronic high-dose vitamin B₆ intake (generally in gram quantities daily over many months) has been linked to severe sensory neuropathy characterized by numbness, impaired proprioception, and paresthesia in a “stocking-glove” distribution. Cases of progressive gait instability and loss of balance have been documented in patients taking extremely high doses for extended periods, with symptoms in some instances proving irreversible. Neuropathy is believed to result from pyridoxine neurotoxicity to dorsal root ganglia when plasma levels are excessively high. Notably, these neurotoxic effects are rarely seen at doses below 100 mg/day in adults; typical therapeutic doses are well below the toxic threshold and are considered safe.^[10]

Other uncommon adverse effects reported with very high doses include dermatological lesions (photosensitivity and skin rash), gastrointestinal upset, and in some cases dependency syndromes (e.g. a proposed phenomenon where abrupt cessation of 200 mg/day long-term caused withdrawal-like symptoms).^[6]

Overall, when used at the prescribed therapeutic doses and duration, side effects of pyridoxine HCl Injection are minimal. Patients are advised to report any unusual numbness, tingling, or coordination problems, as these may signal neurotoxicity if dosing is excessive.^[10]

Pyridoxine (vitamin B₆) is generally considered safe for use during pregnancy when administered at recommended doses. Adequate maternal pyridoxine levels are important for fetal development, and the vitamin is present in prenatal vitamins in amounts roughly equivalent to the Recommended Dietary Allowance (around 1.9 mg per day for pregnant women). There is no evidence of fetal harm from normal physiologic supplementation of vitamin B₆; historically, the FDA categorized pyridoxine as Pregnancy Category A for standard doses, indicating that controlled studies in pregnant women have not shown a risk to the fetus.^[11]

Pyridoxine has been extensively used to treat nausea and vomiting of pregnancy, reflecting its safety profile. In clinical practice, the American College of Obstetricians and Gynecologists (ACOG) recommends pyridoxine (10–25 mg three or four times daily) as a first-line treatment for morning sickness, given its efficacy in reducing nausea and its excellent safety record. Pyridoxine’s use in pregnancy, often in combination with doxylamine, has not been associated with teratogenic effects in either the first trimester or later trimesters.^[12]

While routine dietary or prenatal vitamin levels of pyridoxine are clearly safe and beneficial in pregnancy, extremely high pharmacological doses are not routinely advised unless there is a clear medical indication. Doses greatly exceeding the nutritional requirements (for example, hundreds of milligrams daily) have not been studied in randomized trials for safety, so one should avoid mega doses in pregnancy unless treating a specific condition (such as pyridoxine-responsive seizures) under careful supervision. Notably, older classification systems indicated that using pyridoxine above the usual recommended intake falls under Pregnancy Category C, reflecting that risk cannot be ruled out without more data.^[11]

In practice, this means that while normal doses are safe, any use of pyridoxine beyond typical supplemental levels during pregnancy should be guided by a healthcare provider’s assessment of risk versus benefit. Pyridoxine is also considered safe during lactation in normal amounts, although exceedingly high doses might transiently suppress prolactin levels and were historically used (in much larger doses than nutritional needs) to suppress lactation.^[11]

Overall, pyridoxine HCl Injection can be used in pregnant patients if needed for deficiency or other indications, with prudent dosing and medical oversight.

503A vs 503B

503A pharmacies compound products for specific patients whose prescriptions are sent by their healthcare provider.
503B outsourcing facilities compound products on a larger scale (bulk amounts) for healthcare providers to have on hand and administer to patients in their offices.

Learn More