Usage
Liver Extract + Thiamine is used to treat or prevent thiamine deficiency (vitamin B1 deficiency), which can lead to beriberi (affecting the cardiovascular or nervous system) and Wernicke-Korsakoff syndrome (a neurological disorder). Liver extract is sometimes included as a source of other B vitamins and iron. Thiamine is crucial for carbohydrate metabolism, energy production, and nerve function. Liver extract may stimulate red blood cell production.
Pharmacologically, thiamine is classified as a vitamin.
Alternate Names
Vitamin B1; Thiamin; Aneurin. Brand names vary depending on the manufacturer and region.
How It Works
Pharmacodynamics: Thiamine acts as a coenzyme in carbohydrate metabolism, specifically in the conversion of pyruvate to acetyl-CoA, a crucial step in the Krebs cycle (energy production). It’s also essential for nerve function, possibly through its role in maintaining myelin sheath integrity and nerve conduction velocity. Liver extract can stimulate red blood cell production due to its iron and vitamin B12 content.
Pharmacokinetics: Thiamine is absorbed in the small intestine and is transported to tissues. It’s metabolized in the liver and excreted primarily through the kidneys. Liver extract components, including iron and other B vitamins, have varying absorption, metabolism, and elimination pathways.
Mode of Action: Thiamine’s coenzyme form, thiamine pyrophosphate (TPP), is essential for several enzymatic reactions, including the decarboxylation of pyruvate and alpha-ketoglutarate in the Krebs cycle, and in the pentose phosphate pathway. It’s also involved in the synthesis of acetylcholine and other neurotransmitters. There’s no direct receptor binding or enzyme inhibition in its primary mechanism.
Dosage
Standard Dosage
Adults:
Mild Thiamine Deficiency: 25-100 mg orally once daily.
Severe Thiamine Deficiency: 100 mg orally two to three times daily. For severe deficiency, parenteral administration (IM or IV) may be preferred for faster and more reliable delivery.
Children:
Dosage is weight-based and should be determined by a pediatrician. Generally, the RDA is 0.3 to 0.7 mg/day for children under 3 and increases with age.
Special Cases:
- Elderly Patients: Standard adult dosing; careful assessment of nutritional status is essential.
- Patients with Renal Impairment: Monitor for potential toxicity at higher doses; dose adjustment may be needed.
- Patients with Hepatic Dysfunction: Thiamine absorption may be impaired; parenteral administration might be required.
- Patients with Comorbid Conditions: Assess for other nutritional deficiencies and adjust accordingly. Conditions like diabetes or alcohol use disorder increase thiamine requirements.
Clinical Use Cases
- Intubation/Surgical Procedures/Mechanical Ventilation/ICU Use: Dosages may vary significantly depending on the patient’s condition and needs. Consult specialized resources and clinical guidelines for recommendations in these settings. Parenteral administration is often preferred in acute care settings.
- Emergency Situations (e.g., Wernicke encephalopathy): 100 mg IV initially, followed by 50-100 mg daily IM or IV until the patient is on a regular, balanced diet.
Dosage Adjustments
Dose modifications are essential based on patient-specific factors such as renal/hepatic dysfunction, metabolic disorders, or genetic polymorphisms affecting drug metabolism.
Side Effects
Common Side Effects
Headache, nasal congestion, flushing, fatigue, allergic reactions (rare), gastrointestinal discomfort.
Rare but Serious Side Effects
Anaphylaxis (severe allergic reaction), pulmonary edema, difficulty breathing.
Long-Term Effects
No specific long-term adverse effects are typically associated with thiamine or liver extract used for deficiency treatment.
Adverse Drug Reactions (ADR)
Severe allergic reactions require immediate medical intervention.
Contraindications
Hypersensitivity to thiamine or any component of the formulation. Use caution in patients with hemochromatosis (iron overload) as liver extract contains iron.
Drug Interactions
Thiamine can interact with certain medications, including some antibiotics (e.g., azithromycin, clarithromycin, erythromycin) and trimethoprim. It can also interact with loop diuretics like furosemide. Alcohol can interfere with thiamine absorption. Liver extract may interact with iron chelators or other iron supplements. Consult drug interaction databases for a comprehensive list.
Pregnancy and Breastfeeding
Thiamine is considered safe during pregnancy and breastfeeding at recommended daily allowances (RDAs). Higher therapeutic doses should be used under medical supervision and only if clearly necessary. Limited information is available regarding the safety of liver extract during pregnancy and breastfeeding; caution is advised.
Drug Profile Summary
- Mechanism of Action: Coenzyme in carbohydrate metabolism, essential for energy production and nerve function.
- Side Effects: Generally well-tolerated; rare allergic reactions possible.
- Contraindications: Hypersensitivity to thiamine or components.
- Drug Interactions: Certain antibiotics, diuretics, and alcohol.
- Pregnancy & Breastfeeding: Generally safe at RDA levels.
- Dosage: Varies based on indication and severity of deficiency.
- Monitoring Parameters: Monitor for resolution of deficiency symptoms (e.g., beriberi, Wernicke encephalopathy) and any adverse effects.
Popular Combinations
Thiamine is often combined with other B vitamins in B-complex formulations.
Precautions
Pre-screening for allergies and relevant medical conditions (e.g., hemochromatosis, liver disease, renal disease) is recommended. Monitor renal function in patients receiving high parenteral doses, especially those with pre-existing renal impairment. Alcohol should be avoided or minimized in patients with thiamine deficiency.
FAQs (Frequently Asked Questions)
A: It varies depending on the severity of deficiency. Mild thiamine deficiency: 25-100 mg orally once daily for adults. Severe deficiency may require higher doses and parenteral administration.
A: Primarily used to treat and prevent thiamine deficiency, beriberi, and Wernicke-Korsakoff syndrome.
Q3: What are the common side effects?
A: Generally well-tolerated. Possible side effects include headache, nasal congestion, flushing, and fatigue. Rarely, allergic reactions may occur.
Q4: Are there any contraindications?
A: Known hypersensitivity to thiamine or any component of the formulation.
Q5: What are the key drug interactions?
A: Interactions may occur with certain antibiotics, loop diuretics, and alcohol. Check drug interaction resources for specific interactions.
Q6: Can it be used during pregnancy and breastfeeding?
A: Thiamine is generally considered safe during pregnancy and breastfeeding at RDA levels. Higher doses should be used with caution and under medical supervision. Consult a healthcare provider for guidance on liver extract use during pregnancy and breastfeeding.
A: Thiamine is primarily metabolized in the liver and excreted by the kidneys.
Q8: What is the role of thiamine in the body?
A: It’s a crucial coenzyme in carbohydrate metabolism, essential for energy production, and it plays a role in nerve function.
Q9: What should patients be monitored for?
A: Resolution of thiamine deficiency symptoms, including those of beriberi and Wernicke-Korsakoff syndrome. Monitor for adverse effects, especially in patients with renal impairment.
