Stability of famotidine 20 and 40 mg/L and amino acids in total parenteral nutrient solutions

The stability of famotidine in total parenteral nutrient (TPN) solutions and the concentrations of amino acids in the presence of famotidine were determined. Two famotidine concentrations (20 mg/L and 40 mg/L) and two amino acid concentrations (20 g/L and 42.5 g/L) were studied under the following storage conditions: refrigerated for 24 hours and then kept at room temperature (20-22 degrees C) for 24 hours, at room temperature for 48 hours, or refrigerated for seven days. Control TPN solutions were studied under the same storage conditions. TPN solutions also contained dextrose 25%, electrolytes, trace elements, and vitamins. Famotidine concentration was determined at 0, 24, and 48 hours and at seven days by high-performance liquid chromatography. Amino acid concentration was determined in the TPN solutions containing 42.5 g/L of amino acids without famotidine and with famotidine 40 mg/L under both 48-hour storage conditions. At 24 hours, all solutions retained at least 95% of the initial famotidine concentration. Seven of the eight famotidine solutions retained more than 95% of the initial famotidine concentration at 48 hours. All samples refrigerated for seven days retained more than 95% of the initial famotidine concentration. The concentration of amino acids in TPN solutions containing 42.5 g/L of amino acids was not affected by the addition of famotidine 40 mg/L under either 48-hour storage condition. Famotidine in concentrations of 20 mg/L and 40 mg/L is stable under the studied 48-hour storage conditions in TPN solutions containing amino acid concentrations of either 20 g/L or 42.5 g/L.(ABSTRACT TRUNCATED AT 250 WORDS)     

Modeling of relationships between pharmacokinetics and blockade of agonist-induced elevation of intraurethral pressure and mean arterial pressure in conscious dogs treated with alpha(1)-adrenoceptor antagonists.

Fiduxosin is a new alpha(1)-adrenoceptor antagonist targeted for the treatment of symptomatic benign prostatic hyperplasia. The purpose of this study was to determine and compare the potencies of the alpha(1)-adrenoceptor antagonists terazosin, doxazosin, tamsulosin, and fiduxosin, based on relationships between plasma drug concentrations and blockade of phenylephrine (PE)-induced intraurethral (IUP) and mean arterial pressure (MAP) responses after single oral dosing in conscious male beagle dogs. Magnitude of blockade and plasma concentrations were evaluated at selected time points over 24 h. All drugs produced dose-dependent antagonism of PE-induced IUP and MAP responses. When IUP and MAP blockade effects were plotted against drug plasma concentrations, direct relationships were observed that were well described by the sigmoidal maximal effect model. IUP IC(50) values for terazosin, doxazosin, tamsulosin, and fiduxosin were 48.6, 48.7, 0.42, and 261 ng/ml, respectively. MAP IC(50) values were 12.2, 13.8, 1.07, and 1904 ng/ml, respectively. Uroselectivity index values, defined as MAP IC(50)/IUP IC(50), were 0.25, 0.28, 2.6, and 7.3, respectively. These results extend previous observations with terazosin in this model, showing that doxazosin exhibits a uroselectivity index comparable to terazosin, consistent with the lack of alpha(1)-adrenoceptor subtype selectivity or uroselectivity of these drugs. Tamsulosin, an alpha(1a)-/alpha(1d)-subtype selective agent, had an index value approximately 10-fold greater than the nonselective drugs. Based on its pharmacokinetic profile and a relative uroselectivity 29-fold greater than the nonselective drugs, fiduxosin is expected to exhibit greater selectivity for urethral compared with vascular alpha(1)-adrenoceptors in human and should be a novel, long-acting, uroselective alpha(1)-adrenoceptor antagonist.     

Diaphragm of the gallbladder: a case report.

Gallbladder anomalies are rare and normally affect its shape, size, and position. We report on a 3-year-old boy with a gallbladder divided transversally by a windsock-type diaphragm, isolating the fundus from the rest of the biliary tree. Bilobed and multiseptated gallbladder have been described before, but this is the first isolated case of a congenital hourglass gallbladder.     

Complications of lymphangiomas in children.

One hundred ninety-three cases of lymphangioma presenting in children were reviewed over a 10-year period. The diagnosis was established before 5 years of age in 87.0%. The distribution of lymphangiomas was: cervical (31.4%), craniofacial (18.9%), extremity (18.9%), trunk (9.2%), intraabdominal (9.2%), cervicoaxillothoracic (4.9%), multiple (3.8%), cervicomediastinal (2.2%), and intrathoracic (1.6%). Of 164 patients undergoing primary therapy, total excision was performed in 77.4% and partial excision in 20.7% with recurrence rates of 11.8% and 52.9%, respectively. Thirty-eight percent of all operations for lymphangiomas were performed for resection of recurrent or residual disease. The incidence of postoperative complications was 31.3%. Forty-four additional procedures were required to manage these complications. Sclerotherapy with 50% dextrose was used as an adjunct in 9.5%. Recurrences were seen after total resection in 17.6% of operations in which 50% dextrose was used and 11.8% in which it was not used. Seroma formation was noted in 3.5% of total resections and 40.0% of resections for recurrent disease in which adjunctive sclerotherapy with 50% dextrose was used. Seromas occurred in 9.8% of wounds in which local drains were used and 3.6% of wounds in which drains were not used. Infectious complications occurred after 6.6% of operations using perioperative antibiotics and 3.5% not using antibiotics. The management of lymphangiomas in children remains a difficult problem. Despite being benign lesions, lymphangiomas are attended by a high rate of morbidity from complications of the disease and its management. Complete excision still offers the best chance for complete cure. Sclerotherapy with 50% dextrose is not beneficial in the management of recurrent disease or postoperative seromas. Local drains and perioperative antibiotics do not appear to diminish the incidence of seromas and infectious complications, respectively.