Effect of an anabolic steroid on nitrogen balance and amino acid patterns after total hip replacement.

The effect of an anabolic steroid, nandrolone decanoate, on nitrogen balance and plasma and muscle amino acid concentrations was studied in patients undergoing total hip replacement and receiving daily postoperative infusions of 5% dextrose and 3.5% amino acids. An intramuscular injection of 200 mg immediately after operation resulted in a nitrogen balance of -48 mg N/kg . day for the first 3 days, as compared to 102 mg N/kg . day in noninjected controls. After steroid injection there was also an attenuation of trauma-induced changes in amino acid concentrations in muscle but not in plasma. This suggests that nandrolone decanoate may act directly on muscle to reduce the protein catabolism which follows a major form of operative trauma.