Manganese Sulphate

Usage

Manganese sulfate is prescribed for the prevention and treatment of manganese deficiency. It plays a crucial role as a cofactor in numerous enzymatic systems, particularly those involved in carbohydrate and protein metabolism. While not a distinct pharmacological classification like “antibiotic” or “analgesic,” it is categorized as a trace element or dietary supplement essential for normal physiological function. Its mechanism of action involves acting as a cofactor for enzymes such as glycosyltransferases and arginase, and is essential for normal development of bone. It is vital for synthesizing mucopolysaccharides, which are crucial components of connective tissues.

Alternate Names

Manganese(II) sulfate, manganese sulfate monohydrate (if monohydrated), manganese sulfate pentahydrate (if pentahydrated). Brand names can include Mangimin and MN-50.

How It Works

Pharmacodynamics: Manganese acts as a cofactor for many enzymes, including arginase, pyruvate carboxylase, and superoxide dismutase (SOD). It impacts various physiological processes, from bone development and wound healing to carbohydrate and protein metabolism.

Pharmacokinetics:

• Absorption: Oral absorption of manganese is poor, generally less than 5%. Absorption is influenced by dietary factors like iron and calcium.
• Distribution: Following absorption, manganese is distributed throughout the body, concentrating primarily in the mitochondria-rich tissues like the liver, kidneys, pancreas, pituitary gland, and bones.
• Metabolism: Manganese isn’t extensively metabolized in the conventional sense.
• Elimination: Primarily excreted via the biliary route (feces), with negligible urinary excretion. Impaired biliary function can lead to manganese accumulation.

Dosage

Standard Dosage

Adults:

The recommended daily allowance for adults is 1.8 mg for women and 2.3 mg for men. As a dietary supplement, the typical oral dose ranges from 2-5 mg daily for the prevention of deficiency. For treating deficiency, the dosage is determined by the prescriber and can range from 0.5-5.6 mg daily for up to 24 weeks or as needed. For parenteral administration (TPN), 60-100 mcg/day IV is recommended for adults.

Children:

The recommended daily allowance for children varies by age, ranging from 0.3-1.5 mg daily for infants and children 1 to 3 years, 1.5-2 mg daily for children 4 to 6 years and 2-3 mg daily for children 7-10 years old. For parenteral administration, 1 to 50 mcg/day is recommended. Use caution in premature neonates as manganese chloride injection can contain aluminum. Dosage adjustments are usually based on the severity of the deficiency.

Special Cases:

• Elderly Patients: Refer to adult dosing.
• Patients with Renal Impairment: No specific dosage adjustments are typically required, but caution is advised.
• Patients with Hepatic Dysfunction: Use with caution as manganese is primarily eliminated through the bile. Dosage adjustments may be necessary depending upon the degree of impairment.
• Patients with Comorbid Conditions: Patients with biliary disease or liver disease should use manganese with caution, as it may accumulate and lead to toxicity.

Clinical Use Cases Dosage recommendations for specific medical settings, such as intubation, surgical procedures, mechanical ventilation, or emergency situations, are not clearly established for manganese supplementation. It is primarily used for its role in metabolism and preventing/treating deficiency. Magnesium sulfate (MgSO4) is frequently used in these situations. Do not confuse manganese sulfate (MnSO4) with magnesium sulfate (MgSO4).

Dosage Adjustments Dosage adjustments are made primarily based on individual needs and the severity of manganese deficiency, as well as based on hepatic function and other comorbid conditions if needed.

Side Effects

Common Side Effects

Manganese supplementation at recommended dosages typically does not cause significant side effects.

Rare but Serious Side Effects

At high doses or with chronic inhalation, manganese can cause neurotoxicity, manifesting as Parkinson’s disease-like symptoms (manganism), including tremors, muscle rigidity, and cognitive impairment.

Long-Term Effects

Chronic exposure to high levels of manganese, primarily through inhalation, is associated with neurotoxicity.

Adverse Drug Reactions (ADR)

Serious ADRs are rare with oral manganese sulfate used at recommended dosages. With chronic inhalation or excessive intravenous administration, neurotoxicity (manganism) is the major concern.

Contraindications

No absolute contraindications are listed in the manufacturer’s US labeling for oral manganese sulfate. However, relative contraindications include severe liver disease and biliary obstruction due to the risk of manganese accumulation.

Drug Interactions

Manganese can interact with certain medications, including:

• Antipsychotics: May worsen manganese-related side effects.
• Iron, calcium, and other minerals: Can affect manganese absorption.

Some sources state that manganese has no known interactions.

Pregnancy and Breastfeeding

Pregnant and lactating women have increased manganese requirements (2.0 mg/day and 2.6 mg/day, respectively) but should not exceed the Upper Tolerable Intake level (UL). Chronic inhalation of manganese is considered likely unsafe during pregnancy and breastfeeding.

Drug Profile Summary

• Mechanism of Action: Cofactor for various enzymes involved in metabolic processes.
• Side Effects: Generally well-tolerated at recommended doses; high doses or chronic inhalation can cause neurotoxicity.
• Contraindications: Relative contraindications include severe liver disease and biliary obstruction.
• Drug Interactions: Limited interactions with medications, primarily antipsychotics. Iron, calcium, and other minerals can impact absorption.
• Pregnancy & Breastfeeding: Increased requirements during pregnancy and lactation; chronic inhalation exposure is contraindicated.
• Dosage: Adult RDA: 1.8-2.3 mg/day. For deficiency: 0.5-5.6 mg/day orally or 60-100 mcg/day IV.
• Monitoring Parameters: Serum manganese levels can be monitored in cases of suspected toxicity or deficiency.

Popular Combinations

Manganese is often included in multivitamin/mineral supplements. Specific drug combinations with manganese sulfate for therapeutic purposes are not well-established.

Precautions

Patients with liver disease or biliary obstruction should exercise caution with manganese supplementation. Monitor for signs of neurotoxicity, particularly with prolonged high-dose exposure.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Manganese Sulfate?

A: The recommended dietary allowance (RDA) for adults is 1.8 mg/day for women and 2.3 mg/day for men. Therapeutic doses for deficiency typically range from 0.5 mg to 5.6 mg daily, or 0.06 mg to 0.1 mg/day, with higher doses up to 20 mg daily having been reported for some conditions like osteoporosis, though these are not typically given to treat manganese deficiency. Intravenously, 60-100 mcg/day are given to adults, and 1-50 mcg/day are given to children.

Q2: What are the signs and symptoms of manganese deficiency?

A: Signs and symptoms of manganese deficiency are rare and can be nonspecific, including impaired growth, skeletal abnormalities, impaired glucose tolerance, and altered carbohydrate and lipid metabolism.

Q3: How is manganese deficiency diagnosed?

A: Diagnosis of manganese deficiency is primarily based on low serum manganese levels combined with clinical presentation. It is often challenging to diagnose due to the nonspecific nature of the symptoms.

Q4: What foods are rich in manganese?

A: Nuts, whole grains, legumes, leafy green vegetables, and tea are good dietary sources of manganese.

Q5: What are the long-term effects of manganese toxicity?

A: Chronic manganese toxicity, primarily through inhalation, can lead to manganism, a neurological disorder resembling Parkinson’s disease, characterized by tremors, muscle rigidity, and cognitive impairment.

Q6: Can manganese sulfate be given intravenously?

A: Yes, manganese sulfate can be administered intravenously, typically as part of total parenteral nutrition (TPN) solutions to prevent deficiency in individuals unable to absorb nutrients orally.

Q7: Is manganese safe during pregnancy?

A: Manganese is essential during pregnancy, but it is important to stay within the RDA and UL. Chronic inhalation exposure is considered likely unsafe.

Q8: How is manganese toxicity treated?

A: Treatment for manganese toxicity primarily involves removing the source of exposure. Chelation therapy may be considered in severe cases.

Q9: What is the role of manganese in the body?

A: Manganese acts as a cofactor for numerous enzymes involved in various metabolic processes, including carbohydrate and protein metabolism, bone formation, and antioxidant defense.

Q10: Can manganese interact with other supplements?

A: Yes, high doses of iron or calcium can interfere with manganese absorption.