Usage
Manganese chloride is primarily used as a supplement to intravenous solutions given for total parenteral nutrition (TPN). It helps to maintain manganese serum levels and prevent deficiency symptoms in patients who are unable to obtain sufficient manganese through oral intake. It is classified as a mineral supplement. Its mechanism of action involves providing the essential trace element manganese, which is a cofactor for numerous enzymes involved in various metabolic processes, including carbohydrate, protein, and lipid metabolism.
Alternate Names
Manganese(II) chloride, MnCl2
How It Works
Pharmacodynamics: Manganese is an essential trace element crucial for various physiological processes. It acts as a cofactor for enzymes involved in carbohydrate metabolism, protein synthesis, lipid metabolism, and antioxidant defense. It plays a vital role in bone development, wound healing, and immune function.
Pharmacokinetics:
- Absorption: Orally administered manganese is poorly absorbed, with only 1-2% reaching systemic circulation. Absorption is enhanced in iron-deficient states. Intravenously administered manganese directly enters systemic circulation.
- Distribution: Concentrates in the mitochondria-rich organs, including the liver, kidneys, pancreas, pituitary gland, and bones.
- Metabolism: Primarily through biliary excretion.
- Elimination: Predominantly via bile; urinary excretion is negligible.
Mode of Action: Manganese functions as a cofactor for numerous enzymes, including glycosyltransferases, arginase, glutamine synthetase, and superoxide dismutase. It participates in metabolic reactions by facilitating enzyme-substrate interactions and stabilizing enzyme structure.
Elimination Pathways: Hepatic, primarily through biliary excretion.
Dosage
Standard Dosage
Adults (TPN):
- 55-800 mcg/day intravenously after dilution in at least 100 mL of fluid.
- Recommendations favor 60-100 mcg/day to avoid neurotoxicity.
- Monitor plasma manganese levels to guide subsequent administration.
Children (TPN):
- 2-10 mcg/kg/day intravenously after dilution.
- Expert recommendations suggest 1 mcg/kg/day (up to a maximum of 50 mcg/day) to avoid neurotoxicity.
- Monitor plasma levels.
- Use with caution in premature neonates due to the aluminum content in the injection.
Special Cases:
- Elderly Patients: Same as adult dosing but monitor closely for toxicity.
- Patients with Renal Impairment: Use with caution; aluminum toxicity is a concern. Monitor renal function and plasma manganese levels closely. Dosage reduction may be necessary.
- Patients with Hepatic Dysfunction: Reduce dose or omit as manganese is primarily eliminated through bile. Monitor liver function tests.
- Patients with Comorbid Conditions: Exercise caution and consider individual patient factors.
Clinical Use Cases
The primary clinical use case is as a supplement in Total Parenteral Nutrition (TPN). Dosing is as outlined above. Manganese Chloride is not indicated for use in intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations outside the context of preventing or treating manganese deficiency in patients receiving TPN.
Dosage Adjustments
Adjustments based on renal or hepatic function and monitoring of plasma manganese levels are crucial to prevent toxicity. Individual patient factors and comorbid conditions should also be considered.
Side Effects
Common Side Effects
No common side effects are reported when administered at appropriate doses for TPN.
Rare but Serious Side Effects
Manganism (Parkinson’s disease-like symptoms including tremors, gait disturbances, and facial muscle spasms), neurotoxicity (headache, insomnia, exaggerated tendon reflexes, memory loss, impaired motor skills, psychiatric issues), and aluminum toxicity in patients with renal impairment.
Long-Term Effects
Chronic manganese toxicity can lead to irreversible neurological damage.
Adverse Drug Reactions (ADR)
Neurotoxicity, aluminum toxicity (particularly in renal impairment), and hypersensitivity reactions (rare).
Contraindications
Direct intramuscular or intravenous injection of undiluted manganese chloride is contraindicated due to its acidic pH and potential for tissue irritation. Known hypersensitivity to manganese.
Drug Interactions
- Tetracycline and Quinolone Antibiotics: Manganese can chelate these antibiotics, reducing their absorption. Administer manganese at least 2 hours before or 4 hours after tetracyclines and at least 1 hour after quinolones.
- Antacids and Laxatives (Magnesium-containing): These can reduce manganese absorption. Administer manganese at least 1 hour before or 2 hours after these medications.
- Antipsychotic drugs: May potentiate manganese neurotoxicity. Monitor patients closely for adverse effects.
- Reserpine: Can lower manganese levels.
Pregnancy and Breastfeeding
The safety of manganese chloride supplementation during pregnancy and breastfeeding has not been established. Use only if clearly needed and after careful risk-benefit assessment. Animal studies are limited and it is unknown if manganese is excreted in breast milk.
Drug Profile Summary
- Mechanism of Action: Provides essential trace element manganese, acting as a cofactor for multiple enzymes.
- Side Effects: Generally well-tolerated at recommended TPN doses; neurotoxicity and aluminum toxicity are potential concerns.
- Contraindications: Direct IV/IM injection of undiluted solution, hypersensitivity to manganese.
- Drug Interactions: Tetracycline and quinolone antibiotics, magnesium-containing antacids/laxatives, antipsychotic drugs, reserpine.
- Pregnancy & Breastfeeding: Safety not established; use with caution.
- Dosage: Adults (TPN): 55-800 mcg/day IV; Children (TPN): 2-10 mcg/kg/day IV.
- Monitoring Parameters: Plasma manganese levels, renal and liver function tests (as appropriate).
Popular Combinations
Primarily used as a single agent in TPN formulations.
Precautions
- Monitor for signs of manganese toxicity, particularly neurological symptoms.
- Monitor aluminum levels in patients with renal impairment.
- Assess liver function in patients with hepatic dysfunction.
- Exercise caution in pregnant and breastfeeding women.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Manganese Chloride in TPN?
A: Adults: 55-800 mcg/day IV. Children: 2-10 mcg/kg/day IV. Expert recommendations favor lower doses (Adults: 60-100 mcg/day, Children: 1 mcg/kg/day up to 50 mcg/day) to minimize the risk of neurotoxicity.
Q2: How should Manganese Chloride be administered?
A: Intravenously only after dilution in at least 100 mL of fluid. Never administer directly IM or IV as the undiluted solution is acidic and can cause tissue irritation.
Q3: What are the signs of manganese toxicity?
A: Tremors, difficulty walking, facial muscle spasms, headache, insomnia, exaggerated tendon reflexes, memory loss, impaired motor skills, psychiatric disturbances.
Q4: What are the contraindications to using Manganese Chloride?
A: Direct IM/IV injection of undiluted solution, known hypersensitivity to manganese.
Q5: What are the significant drug interactions with Manganese Chloride?
A: Tetracycline and quinolone antibiotics, magnesium-containing antacids and laxatives, antipsychotic drugs, reserpine.
Q6: Can Manganese Chloride be used during pregnancy and breastfeeding?
A: Safety is not established. Use with caution and only if the potential benefits outweigh the potential risks to the fetus or infant. Consult a specialist.
Q7: How is Manganese Chloride eliminated from the body?
A: Primarily through biliary excretion.
Q8: What should be monitored in patients receiving Manganese Chloride?
A: Plasma manganese levels, renal and liver function tests (as appropriate), and clinical signs of manganese toxicity.
Q9: What is the role of manganese in the body?
A: Manganese is an essential trace element and cofactor for various enzymes involved in metabolic processes, bone development, wound healing, and immune function.
Q10: Why is Manganese Chloride used in TPN?
A: To prevent or treat manganese deficiency, which can occur in patients receiving long-term TPN.
