Magnesium Sulfate

Indications & Dose:

(parenteral): Eclampsia prophylaxis, preterm labor.

DOSAGE

Adult:

• BY INTRAMUSCULAR

4-5 g  over 20 minutes followed by infusion at a rate of 1gm/hour. Recurrence of seizures an additional bolus 2-4gm required. 

Contraindications:

Renal failure (Mg toxicity), hypermagnesemia: do not use cathartics in patients with appendicitis, impaction, intestinal obstruction, or perforation; do not use parenterally in patients with heart block, myocardial damage 

Side Effects:

Cautions:

Precautions:

Diarrhea, digitalized patients, impaired renal function (monitor Mg levels) 

Interaction:

Drugs

Allopuinol, cefpodoxime, ciprofloxacin, atenolol, tetracyclines, iron, salts, isoniazid, ketocanazole, lomefoxacin, norflaxacin, ofloxacin, pefloxacin, penicillamine, trovafoxacin: Decreased PO effectiveness of these drugs with PO magnesin products

Aspirin: Decreased salicylate concentrations due to alkalnization of urine with oral magneisum hydroxide

Glipizide, glyburide: increased absorption of these drugwith oral magnesium hydroxide

Nifedipine: Decreased effect of nifedipine with parenteral magnesium sulfate

Quinidine: Increased quinidine concentrations with oral magnesium products

Sodium polystyrene sulfanate. Systemic alkalosis with oral magnesium products

Succinylicholine: Increased toxicity of these drugs with parenteral magnesium sulfate

Labs False increase: Serum alkaline phosophatase

 Special considerations monitoring parameters

Parenteral magnesium: Knee jerk reflexes prior to each dose (do not administer if absent), respiration rate (do not administer if < 16/min). urine output (do not administer if < 100 ml) during 4 hr preceding each dose), serum magnesium concentrations (normal 1.5-3 mEq/L: therapeutic concentrations for preeclampsia eclampsia convulsions 4-7 mEq/L

Warnings:

Adverse Effects:

Lactations:

Pregnancy and Lactation: Pregnancy category B: compatible with breast feeding

Special Precautions:

Counselling:

Side Effects Or Adverse Reactions:

CNS: Coma, depressed deeptendon reflexes, depression, lethargy, weakness
CV: Decreased BP, heart block, increased pulse
GI: Belching, cramps, (PO) diarrhea, flatulence, impaction, nausea, obstruction, pain, vomiting
Metab: Hypremagnesemia
Resp: Respiratory depression 

Patient And Carer Advice: