Nifedipine Magnesium sulfate

Chi OZ, Poliak P, Weiss HR. Effects of magnesium sulfate and nifedipine on regional cerebral blood flow during middle cerebral artery ligation in the rat. Arch Int Pharma-codyn Ther 1990 304 196-205. 

Tocolytic therapy with nifedipine has been reported in several studies to be at least effective as ritodrine, terbu-taline, or magnesium sulfate, with fewer maternal adverse effects (SEDA-18, 216) (SEDA-20,187) (SEDA-22, 217) (SEDA-23, 211). These observations have been confirmed in two trials in 102 and 54 pregnant women of under 34 weeks gestation, randomized to nifedipine or ritodrine. There were no differences in the time of delivery, but significantly fewer maternal adverse effects in those given nifedipine (41,42). 

Two pregnant women developed bilateral hand contractures after receiving magnesium sulfate either alone or with nifedipine. Two other pregnant women developed muscular weakness and then paralysis when they were given both nifedipine and intravenous magnesium sulfate. Profound hypotension occurred in two women when nifedipine was added to magnesium sulfate and... 

A report describes symptomatic hypocalcaemia (serum calcium levels 5.4 mg/dL) in a woman at 33 weeks gestation after she received magnesium sulfate plus nifedipine." However, this report also describes this effect in a patient taking magnesium sulfate alone. Both women experienced bilateral hand contractures and were successfully treated with calcium gluconate." ... 

Magee LA, Miremadi S, Li J, Cheng C, Ensom MHH, Carleton B, Cote A-M, von Dadelszen P. Therapy with both magnesium sulfate and nifedipine does not increase the risk of serious magnesium-related maternal side effects in women with preeclampsia. AmJ Obstet Gynecol (2005) 193,153-63. 

Koontz SL, Friedman SA, Schwartz ML. Symptomatic hypocalcemia after tocolytic therapy with magnesium sulfate and nifedipine. Am J ObsUt Gynecol (2004) 190,1113-6. 

Glyceryl trinitrate overdose should be treated with the patient s head lowered. Other measures include respiration maintenance, use of plasma expanders, and electrolyte balance. Withdrawal of heparin treatment or dose reduction should be performed with the overdose of heparin. Protamine sulfate may be used to reduce severe bleeding. Heparin should be used with caution with glyceryl trinitrate, aprotinine, alcohol, tobacco, and ACE inhibitors. Nifedipine should be used with care when coadministering with immunosuppressants, magnesium salts, tobacco, digoxin, antineoplastics, calcium channel blockers, antihistamines, antifungals, antiepileptics, antiarrhythmics, and alcohol. 

---