Carnes MagnesiumInMusculoskeletalHealth

7/23/2019 Carnes MagnesiumInMusculoskeletalHealth

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Mike Carnes, D.O., F.A.A.O.

University of Pikeville

Kentucky College of Osteopathic Medicine


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N-methyl-D-aspartate (NMDA) receptors Ca2+channel that is blocked physiologically by Mg2+

Methadone is unique amongst the narcotics

Zinc also can block these receptors

Neuropathic pain Neuronal damage

Acute excitotoxic activity and oxidative stress with rapidCa2+influx

Delayed signaling leading to cell apoptosis is a problemwhen the receptors are blocked pharmacologically

Searching for a pathologically activated NMDA receptorantagonist


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Mitochondrial ATP production

Cofactor in thiamine dependent reactions Cofactor in Na+K+ATPase activity

K+secretion block (deficiency of Mg2+ low K+)

Can inhibit acetylcholine release (myasthenia gravis)

Deficiency may lead to hypocalcemia 20to effect on PTHsecretion

Aerobic metabolism, anaerobic metabolism, glycolysis,oxidative phosphorylation

Cofactor in some 300 enzymatic reactions

Low Mg2+& vitamin D (and some other micronutrients)can contribute to accelerated aging and adverseoutcomes


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Adult

25 grams Bone 50%

25% of the total body Mg2+insoluble mineral phase

99% of extraskeletal Mg2+is intracellular

Less than 1% of total body magnesium is in ECF Serum concentrations are closely regulated by the body

30% protein bound

15% loosely complexed to phosphate and other anions

Serum level below 1.8 mg/dL is indicative of total bodymagnesium deficit


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Nuts, unpolished grains, green leafy vegetables, halibut

Meats, lentils, starches, milk Absorbed in distal jejunum and ilium (30 40%)

1, 25-(OH)2D can stimulate this to reach 70% in times ofmagnesium depletion

Low protein diets (less than 30 grams/day) decreasesmagnesium absorption

RDA

Women 360 mg/d (14-18) tapers to 320 mg/d Men 420 mg/d gradually increasing with age

60 % of US population does not get their RDA

Excreted by nephron in the loop of Henle


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Extremely rare in the absence of renal dysfunction % absorbed inversely related to amount ingested

Renal function may worsen with supplementation

Tetanus therapeutic dose may also effect diaphragm

4.8 mg/dL - hypotension, neuromuscular blockade

9 mg/dL - loss of DTRs, respiratory suppression, nausea,

lethargy 20 mg/dL asystole


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Neuropathic pain

Migraines/headache, Bruxism, Nocturnal muscle cramp

Chronic Fatigue Syndrome / Fibromyalgia

Sickle crisis / anemia (pain, RBC dehydration, vascular

adhesion) Dysmenorrhea

Post-operative pain

Ischemic stroke

Asthma Acute nebulized or IV

Chronic oral

Cardiac arrhythmias (particularly QT prolongation)


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Oral increase by one tab every 3 4 days to bowel

tolerance, then decrease by one tab Topical MgCl 20% cream

Epsom Salt soak (MgCl)

Parenteral

for pain or spasm with intact renal function 4 gram dose intraoperatively

1 1.5 grams per hour

Scale 2.4 2.5 mg/dL = 1 gram mag sulfate in 50 cc NS

2.2 2.3 mg/dL = 2 grams mag sulfate in 100 cc NS




1.5 or below = 8 grams mag sulfate in 500 cc NS


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Harrison's Principles of Internal Medicine, 18th Edition.McGraw-Hill Professional Publishing, 07/2011.

Present Knowledge in Nutrition, 10th Edition., John Wiley& Sons, Inc., 2012

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Carnes MagnesiumInMusculoskeletalHealth