Doses - MAGNESIUM, MAGNESIUM SULFATE, PARENTERAL

Dogs & Cats:

For hypomagnesemia:
a) Magnesium sulfate 25% solution: Dose is dependent on magnitude of intoxication, butusually ranges from 5 - 15 ml IM or IV over 1-2 hours; have calcium gluconateavailable should magnesium intoxication occur. (Seeler and Thurmon 1985)
b) 0.75 - 1 mEq/kg/day administered by a constant rate infusion in D5W. Concentrateshould be diluted to at least 20%. . A lower dose of 0.3 - 0.5 mEq/kg/day may be usedfor an additional 3-5 days as complete repletion occurs slowly. If needed for life-threatening ventricluar arrhythmias: 0.15 - 0.3 mEq/kg may be administered over 5 - 15minutes. (Holland and Chastain 1995)

Ruminants:

For hypomagnesemia (grass and other magnesium-related tetanies):
a) Cattle: Magnesium sulfate 20-50%: 200 ml SQ, followed by a slow IV infusion of 500ml of a calcium/magnesium solution (Calcium borogluconate 23%; MgCl2 6%).(Phillips 1988a)
b) Cattle: 350 ml (250 ml of 25% calcium borogluconate and 100 ml of 10% of magnesium sulfate) by slow IV. If not a proprietary mixture, give calcium first. Relapses occurfrequently after IV therapy, and 350 ml SQ of magnesium sulfate 20% may give moresustained magnesium levels. Alternating calcium and magnesium may prevent adverseeffects. Continue control measures for 4-7 days to prevent relapse.
Sheep and Goats: 50 - 100 ml of above solution (calcium/magnesium).
For whole milk tetany in calves 2-4 months of age: Magnesium sulfate 10% 100 ml;followed by oral magnesium oxide at daily doses of 1 gram PO (0-5 weeks old), 2 gram
PO (5-10 weeks old), and 3 grams PO (10-15 weeks old). (Merrall and West 1986)

Swine:

For adjunctive therapy of malignant hyperthermia syndrome:
a) Magnesium sulfate 50%: Incremental doses of 1 gram injected slowly IV until heart rateand muscle tone are reduced. Use calcium if magnesium-related cardiac arrest occur.(Booth 1988)
Monitoring Parameters -

1) Serum magnesium

2) Physical signs and symptoms associated with hypomagnesemia

3) Serum calcium if indicated
Dosage Forms/Preparations/FDA Approval Status/Withholding Times - Veterinary-Approved Products: There are no parenteral magnesium-only products approvedfor veterinary medicine. There are, however, several proprietary magnesium-containing productsavailable that may also include calcium, phosphorus, potassium and/or dextrose; refer to the individual product's labeling for specific dosage information. Trade names for these products include: Norcalciphos®¯Pfizer, Cal-Dextro® Special, & #2, ¯Fort Dodge, and CMPK®, & Cal-Phos® #2¯(TechAmerica). They are legend (Rx) drugs.

Human-Approved Products:

Magnesium Sulfate Injection 10% (0.8 mEq/ml), 12.5% (1 mEq/ml), & 50% (4 mEq/ml) in 2, 5, 10, 20 & 50 ml amps, vials and/or syringes; Generic; (Rx)