Apatate (cyanocobalamin/pyridoxine HCl (vitamin B6)/thiamine)

No dosing information is available for this tab.

Cyanocobalamin is administered by IM or deep subcutaneous injection. Cyanocobalamin also is administered orally and intranasally. Hydroxocobalamin is administered by IM injection or IV infusion. Oral therapy with vitamin B12 preparations is markedly inferior to parenteral therapy and should be used only for the treatment of dietary vitamin B12 deficiency in patients with normal GI absorption.

Thiamine hydrochloride is usually administered orally. When oral administration is not feasible, when malabsorption is suspected, or in patients with Wernicke's encephalopathy syndrome or high-output heart failure secondary to beriberi, the drug may be administered IM or IV; most clinicians prefer IV administration of thiamine hydrochloride for the treatment of high-output heart failure.

No dosing information is available for this tab.

No dosing information is available for this tab.

Safety of concomitant administration of other cyanide antidotes with hydroxocobalamin (Cyanokit(R)) has not been established. Caution is advised if another cyanide antidote is administered to patients receiving hydroxocobalamin.

Absorption of vitamin B12 from the GI tract may be decreased by aminoglycoside antibiotics, colchicine, extended-release potassium preparations, aminosalicylic acid and its salts, anticonvulsants (e.g., phenytoin, phenobarbital, primidone), cobalt irradiation of the small bowel, and by excessive alcohol intake lasting longer than 2 weeks. Neomycin-induced malabsorption of vitamin B12 may be increased by concurrent administration of colchicine.

Ascorbic acid may destroy substantial amounts of dietary vitamin B12 in vitro; this possibility should be considered when large doses of ascorbic acid are ingested within 1 hour of oral vitamin B12 administration.

Prednisone has been reported to increase the absorption of vitamin B12 and secretion of IF in a few patients with pernicious anemia, but not in patients with partial or total gastrectomy. The clinical importance of these findings is unknown.

Concurrent administration of chloramphenicol and vitamin B12 reportedly may antagonize the hematopoietic response to vitamin B12 in vitamin B12-deficient patients. The hematologic response to vitamin B12 in patients receiving both drugs should be carefully monitored and alternate anti-infectives should be considered.

Although the clinical importance is unknown, thiamine reportedly may enhance the effect of neuromuscular blocking agents.

Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

Pyridoxine/Altretamine

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: The mechanism by which pyridoxine adversely affects response duration while coadministering altretamine is not known at this time and requires further investigation.

CLINICAL EFFECTS: The coadministration of oral pyridoxine with chemotherapy regimens consisting of oral altretamine adversely affected response duration.(1,2)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Although pyridoxine administration significantly reduces the neurotoxicity associated with altretamine, it should not be administered with altretamine due to its adverse effect on response duration.(1,2)

DISCUSSION: In a study, 248 patients with Stages III-IV ovarian epithelial cancer were randomized to one of four cisplatin and altretamine regimens. In each regimen, oral altretamine (200 mg/m2 daily) was administered on days 8-21. In addition, intravenous cisplatin was administered on day 1 (37.5 mg/m2, regimens A and B, or 75 mg/m2, regimens C and D). Oral pyridoxine (300 mg/m2 daily, days 1-21) was added to regimens B and D. While pyridoxine did decrease neurologic toxicity and had no effect on response, pyridoxine was found to adversely affect response duration in all patients. This effect was the greatest in previously untreated patients. In addition, pyridoxine had a slight negative effect on failure-free survival in previously untreated patients.(1)

There are no severe interactions for this drug.

Moderate Interaction: Assess the risk to the patient and take action as needed.

Pyridoxine/Levodopa

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Pyridoxine increases levodopa metabolism, decreasing the amount of levodopa available to the central nervous system.

CLINICAL EFFECTS: The pharmacologic effects of levodopa may be decreased.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: Avoid pyridoxine in patients receiving levodopa alone; however, the interaction can be minimized by giving levodopa with a peripheral decarboxylase inhibitor (e.g. carbidopa, benserazide). Treatment with combination carbidopa-levodopa may contribute to reduced vitamin B6 levels. Higher doses of carbidopa-levodopa may increase the risk of vitamin B6 deficiency. Seizures associated with vitamin B6 deficiency have been reported in the postmarketing setting. In patients taking combination therapy with carbidopa/levodopa, evaluate vitamin B6 levels periodically while on treatment or if symptoms associated with vitamin B6 deficiency are identified. Supplement with vitamin B6 as necessary.

DISCUSSION: In patients with Parkinson's disease, as little as 10 mg of pyridoxine may reverse the clinical benefits as well as the adverse effects of levodopa. Coadministration of levodopa with either carbidopa or benserazide has minimized the effects of this interaction.

Thiamine/Patiromer

SEVERITY LEVEL: 3-Moderate Interaction: Assess the risk to the patient and take action as needed.

MECHANISM OF ACTION: Patiromer may bind to thiamine.(1)

CLINICAL EFFECTS: Concurrent use may result in decreased gastrointestinal absorption and loss of efficacy of thiamine.(1)

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The US manufacturer of patiromer recommends administering patiromer at least 3 hours before or 3 hours after thiamine.(1)

DISCUSSION: An in vitro binding study found potentially clinically significant binding of thiamine by patiromer. It is recommended to take these drugs 3 hours apart.(1)

There is no enhanced messaging for this drug.

• Leber's hereditary optic atrophy

There are no severe contraindications for this drug.

• Atrophic gastritis
• Hypokalemia

There is no enhanced messaging for this drug.

There are no severe adverse reactions for this drug.

Less Frequent

• Diarrhea
• Pruritus of skin

No enhanced messaging available.

No enhanced messaging available.

Adequate and well-controlled studies have not been conducted in pregnant women. However, vitamin B12 requirements are increased in pregnant women. Parenteral preparations should be used during pregnancy only when the potential benefits justify the potential risks to the fetus.

Vitamin B12 is distributed into human milk. Vitamin B12 requirements are increased in lactating women.

Hydroxocobalamin may be administered to lactating women with suspected or known cyanocobalamin poisoning. There is no data available to determine when breastfeeding may be restarted following administration of IV hydroxocobalamin.

No enhanced messaging available.