Serum α_1-acid glycoprotein,sialic acid,and protein binding of disopyramide in normal subjects and cardiac patients

目的：研究日本人充血性心力衰竭（ＣＨＦ）和急性心肌梗塞（ＡＭＩ）病人对血清α１酸性糖蛋白（ＡＧＰ）、唾液酸（ＳＡ）浓度及ＡＧＰ与丙吡胺（Ｄｉｓ）结合的影响．方法：对正常人、ＣＨＦ及ＡＭＩ患者血清样本９７例，采用免疫化学法测定ＡＧＰ浓度，高效液相层析法测定ＳＡ浓度及超滤膜技术和高效液相层析法测定Ｄｉｓ的体外游离浓度．结果：ＣＨＦ及ＡＭＩ患者血清ＡＧＰ浓度较正常人升高．Ｄｉｓ药物游离浓度降低．血清ＳＡ浓度的变化与血清ＡＧＰ浓度的变化趋势一致．结论：ＣＨＦ和ＡＭＩ病人血清药物游离浓度受血清ＡＧＰ结合的影响而变化，应进行临床监测．     

六项放免检测在NIDDM患者诊断早期肝损伤的临床应用

对３９ 例ＮＩＤＤＭ 患者采用放射免疫法（ＲＩＡ）进行甘胆酸（ＣＧ）、透明质酸（ＨＡ）、分泌型免疫球蛋白Ａ（ｓＩｇＡ）、甲胎蛋白（ＡＦＰ）、铁蛋白（ＳＦ）、及癌胚抗原（ＣＥＡ）联合测定。以５１例健康人血清作对照。结果显示：ＮＩＤＤＭ患者血清ＳＦ、ＣＧ、ｓｌｇＡ与对照组比较有显著差异（Ｐ＜ ０．０１）;血清ＨＡ与对照组比较差异明显（Ｐ＜ ０．０５）;血清ＡＦＰ、ＣＥＡ则无差异（Ｐ＞ ０．０５）。检测结果说明对ＮＩＤＤＭ 患者血清ＳＦ、ＣＧ、ｓＩｇＡ、ＨＡ测定对诊断早期肝损伤具有可靠的临床价值。     

粉防己碱对自发性高血压大鼠血管平滑肌细胞增殖及对PDGF-B,bFGF和相关癌基因表达的影响

用［３Ｈ］胸腺嘧啶核苷（［３Ｈ］ＴｄＲ）参入法，电镜，免疫组化，原位杂交方法，在自发性高血压大鼠（ＳＨＲ）观察了粉防己碱（Ｔｅｔ，０．０３μｍｏｌ·ｋｇ－１·ｄ－１×８周ｉｇ）对血管平滑肌细胞（ＶＳＭＣ）增殖的作用及对生长因子ＰＤＧＦ－Ｂ，ｂＦＧＦ的抗原表达及其相关癌基因ｃ－ｓｉｓ，ｃ－ｍｙｃｍＲＮＡ表达的影响．结果发现：Ｔｅｔ在降低ＳＨＲ血压（Ｐ＜０．０１）同时，能减少ＶＳＭＣ的线粒体，粗面内质网和［３Ｈ］ＴｄＲ参入量（Ｐ＜０．０１），并能逆转ＶＳＭＣ增殖时ＰＤＧＦ－Ｂ，ｂＦＧＦ抗原（Ｐ＜０．０５）及ｃ－ｓｉｓ，ｃ－ｍｙｃｍＲＮＡ的表达增强．提示：Ｔｅｔ抑制ＳＨＲ的ＶＳＭＣ增殖与生长因子及癌基因调控的分子生物学机制有关     

淀粉微球的制备与均匀设计

淀粉微球的制备与均匀设计ＰＲＥＰＡＲＡＴＩＯＮＯＦＳＴＡＲＣＨＭＩＣＲＯＳＰＨＥＲＥＳＡＮＤＵＮＩＦＯＲＭＤＥＳＩＧＮ胡新侯新朴（北京医科大学药学院物理化学教研室，北京１０００８３）ＨＵＸｉｎ，ＨＯＵＸｉｎｇ－Ｐｕ（Ｄｅｐｔ．ｏｆＰｈｙｓｉｃａｌＣｈ...     

1-(2,6-二甲基苯氧基)-2-(3,4-二甲氧基苯乙胺基)丙烷盐酸盐对自发性高血压大鼠血管平滑肌细胞增殖及对PDGF-B,bFGF,c-sis,c-myc的影响

用氚胸腺嘧啶核苷（３ＨＴｄＲ）掺入法，电镜，免疫组化，原位杂交方法，在自发性高血压大鼠（ＳＨＲ）观察了１（２，６二甲基苯氧基）２（３，４二甲氧基苯乙胺基）丙烷盐酸盐（ＤＤＰＨ）对血管平滑肌细胞（ＶＳＭＣ）增殖的作用及对生长因子ＰＤＧＦＢ，ｂＦＧＦ及其相关癌基因ｃｓｉｓ与ｃｍｙｃ表达的影响。结果发现：ＤＤＰＨ在降低ＳＨＲ血压同时，能减少肾动脉ＶＳＭＣ的线粒体，粗面内质网和３ＨＴｄＲ掺入量，并能逆转ＶＳＭＣ增殖时ＰＤＧＦＢ，ｂＦＧＦ抗原及ｃｓｉｓ与ｃｍｙｃｍＲＮＡ的表达增强。提示：ＤＤＰＨ能抑制ＳＨＲ的ＶＳＭＣ增殖，与生长因子及癌基因调控的分子生物学机制有关。     

慢性肾功能衰竭患者血清胃动素和胃泌素测定的临床意义

测定慢性肾功能衰竭（ＣＲＦ）患者胃动素（ＭＯＴ）和胃泌素（ＧＡＳ）的水平及其血液透析（ＨＤ）前后变化、并设健康成年人作对比分析。结果示ＣＲＦ患者ＭＯＴ和ＧＡＳ明显高于健康人（Ｐ〈０．００１）。ＨＤ后ＭＯＴ和ＧＡＳ明显降低（Ｐ〈０．０１或０．０５），且ＭＯＴ、ＧＡＳ与血清肌酐（Ｓｃｒ）均呈密切正相关。     

阿齐霉素胶囊溶出度测定

阿齐霉素胶囊溶出度测定尚飞，裴桂芬（辉瑞制药有限公司，大连１１６６００；锦州制药四厂，辽宁１２１００４）ＤＥＴＥＲＭＩＮＡＴＩＯＮＯＦＤＩＳＳＯＬＵＴＩＯＮＲＡＴＥＯＦＡＺＩＴＨＲＯＭＹＣＩＮＣＡＰＳＵＬＥＳ￥ＳＨＡＮＧＦｅｉ；ＰＥＩＧｕｉ－Ｆｅｎ（...     

中国临床药理学与治疗学杂志第二届编委会

主编（Ｅｄｉｔｏｒ＿ｉｎ＿Ｃｈｉｅｆ）:孙瑞元（ＳＵＮＲｕｉ＿Ｙｕａｎ）副主编（ＡｓｓｉｓｔａｎｔＥｄｉｔｏｒ＿ｉｎ＿Ｃｈｉｅｆ）：夏祥厚（ＸＩＡＸｉａｎｇ＿Ｈｏｕ）宋建国（ＳＯＮＧＪｉａｎ＿Ｇｕｏ）张均田（ＺＨＡＮＧＪｕｎ＿Ｔｉａｎ）曾繁典（ＺＥＮＧＦａｎ＿Ｄｉａｎ）顾问（Ａｄｖｉｓｏｒ）：顾方舟（ＧＵＦａｎｇ＿Ｚｈｏｕ）编委（ＢｏａｒｄＭｅｍｂｅｒｓ）（按字母顺序）:陈奇（ＣＨＥＮＱｉ）南昌陈学奎（ＣＨＥＮＸｕｅ＿Ｋｕｉ）合肥崔振宇（ＣＵＩＺｈｅｎ＿Ｙｕ）北京丁德云（ＤＩＮＧＤｅ＿Ｙｕｎ）杭州…     

DDPH对血管平滑肌细胞增殖及PDGF-B、bFGFc-sis、c-myc的影响

目的：观察１－（２，６－二甲基苯氧基）－２－（３，４－二甲氧基苯乙胺基）丙烷盐酸盐（ＤＤＰＨ）对血管平滑肌细胞增殖的作用及对生长因子ＰＤＧＦ－Ｂ，ｂＦＧＦ及其相关癌基因ｃ－ｓｉｓ，ｃ－ｍｙｃ表达的影响。方法：内皮素建立培养的ＶＳＭＣ增殖模型，氚—胸腺嘧啶核苷（３Ｈ－ＴｄＲ）参入法，流式细胞术，１９９７－０３－２３收稿，１９９７－０４－０４修回＊国家教委优秀年轻教师基金资助项目１同济医院心内科，武汉４３００３０作者简介：熊一力，女，４１岁，博士后钱家庆，男，６３岁，博士生导师，药理教研室主任，中国药理学会常务理事免疫细胞化学及Ｎｏｒｔｈｅｒｎｂｌｏｔ杂交方法测定。结果：ＤＤＰＨ能逆转内皮素所致的３Ｈ－ＴｄＲ参入量增多，阻止ＶＳＭＣ由静止期（Ｇ０／Ｇ１期）进入ＤＮＡ合成期（Ｓ期）和有丝分裂期（Ｇ２／Ｍ期），并能逆转内皮素引起的ＰＤＧＦ－Ｂ，ｂＦＧＦ抗原，ｃ－ｓｉｓ，ｃ－ｍｙｃｍＲＮＡ表达增强。结论：ＤＤＰＨ能抑制ＶＳＭＣ增殖，与生长因子及癌基因调控的分子生物学机制有关。     

AUTHENTICATIONOFTHECHINESEDRUG“KUDIDAN”（HERBAELEPHANTOPI）ANDITSSUBSTITUTESUSINGRANDOMPRIMEDPOLYMERASECHAINREACTION（PCR）

ＡＵＴＨＥＮＴＩＣＡＴＩＯＮＯＦＴＨＥＣＨＩＮＥＳＥＤＲＵＧ“ＫＵＤＩＤＡＮ”（ＨＥＲＢＡＥＬＥＰＨＡＮＴＯＰＩ）ＡＮＤＩＴＳＳＵＢＳＴＩＴＵＴＥＳＵＳＩＮＧＲＡＮＤＯＭＰＲＩＭＥＤＰＯＬＹＭＥＲＡＳＥＣＨＡＩＮＲＥＡＣＴＩＯＮ（ＰＣＲ）ＨＣａ...     

Reproducible and time-dependent modification of serum protein binding in Wistar Kyoto rats

INTRODUCTION: The theoretical basis of the influence of (alterations in) plasma protein binding on pharmacokinetics (PK) is well-established. In contrast, the impact of protein binding on pharmacodynamics has not been examined in a systematic manner. Here we present an experimental approach to modify serum protein levels and binding in the rat, in a robust, reproducible, and time-dependent manner. METHOD: Male Wistar Kyoto rats were divided into three different groups. The control group (n=4) did not receive treatment. In the cannulation(-) group (n=6) the rats were instrumented with three permanent blood cannulas. The rats in the cannulation(+) group received in addition to the cannulation a subcutaneous injection of turpentine oil of 100 microl/100 g bodyweight. The effects were characterized in terms of 1) the time course of serum levels of albumin and alpha(1)-acid glycoprotein (AGP), and 2) the effect on the ex vivo serum protein binding of S(-)-propranolol. RESULTS: In control rats the AGP serum concentration was stable at a value of 169+/-16 microg/ml. In the cannulation(-) group a maximum ten- to fifteen-fold increase in serum AGP concentration was observed at 48 h post surgery, followed by a gradual return back to baseline within 1 week. In the cannulation(+) group a similar concentration-time profile for AGP was found, but without a complete return to baseline within 1 week and with a much higher variability. Ex vivo, an increase in AGP serum concentration from 55 to 675 microg/ml resulted in a profound decrease in the free fraction of S(-)-propranolol from 14+/-0.6 to 1.9+/-0.3%. CONCLUSIONS: In conclusion, through cannulation alone the serum protein levels and binding were modified in a robust, reproducible and time-dependent manner. Therefore this experimental approach is suitable for the investigation of the influence of protein binding on both pharmacokinetics and pharmacodynamics.     

Effect of Plasmodium falciparum malaria infection on the plasma concentration of alpha 1-acid glycoprotein and the binding of quinine in Malawian children.

1. We have measured plasma concentrations of alpha 1-acid glycoprotein (AGP) in 18 healthy children and 85 children with falciparum malaria in Malawi. In addition, we determined the degree of protein binding of quinine (QN) in the plasma of 52 of the patients and each of the healthy controls. 2. The mean plasma AGP concentration was higher in patients than in controls (P less than 0.0001) and remained elevated 3 weeks after complete resolution of malaria infection. 3. The mean unbound QN fraction was significantly less (P less than 0.00001) in patients with malaria (0.128 +/- 0.037) than in controls (0.193 +/- 0.051) and significantly higher (P = 0.02) in convalescence (0.153 +/- 0.067) than during acute illness. 4. There were highly significant negative correlations between plasma AGP concentration and the free QN fraction in spiked plasma samples (r = -0.534, P less than 0.0001, n = 93) and in clinical samples (r = -0.484, P less than 0.00001, n = 225). There was a significant positive correlation between plasma concentrations of AGP and another acute phase reactant, C reactive protein (P less than 0.001).     

Serum binding of indapamide in health and disease: primary role of alpha 1-acid glycoprotein

The serum concentrations of alpha-1-acid glycoprotein (AAG), albumin (HSA), and non-esterified fatty acids (NEFA), and the serum binding of indapamide were measured in four groups of individuals: control (healthy) subjects (N = 24), patients with inflammatory syndrome (N = 28), with hepatic (N = 20) and renal (N = 27) insufficiency. Indapamide serum binding was increased in patients with inflammatory syndrome (82.2 +/- 3.4%, P less than .001), decreased in patients with hepatic insufficiency (72.3 +/- 5.9%, P less than .001) and unchanged in patients with renal insufficiency (77.7 +/- 2.8%) as compared with controls (78.2 +/- 3.1%). A multivariate analysis indicated that these changes were mainly related to concomitant changes in AAG concentration (that explained 63% of intersubject variability in bound/free binding ratio), and to a lesser extent to HSA (that explained only 4% of the variability in the binding). These data show that the free fraction of the acidic drug indapamide in serum is affected by pathologic conditions in which changes in AAG concentration occur and that, unexpectedly, HSA plays a negligible role in the binding.     

Pharmacokinetic–pharmacodynamic model for perindoprilat regional haemodynamic effects in healthy volunteers and in congestive heart failure patients

AIMS: We compared the relationships between the plasma concentrations (C) of perindoprilat, active metabolite of the angiotensin I-converting enzyme inhibitor (ACEI) perindopril, and the effects (E) induced on plasma converting enzyme activity (PCEA) and brachial vascular resistance (BVR) in healthy volunteers (HV) and in congestive heart failure (CHF) patients after single oral doses of perindopril. METHODS: Six HV received three doses of perindopril (4, 8, 16 mg) in a placebo-controlled, randomized, double-blind, crossover study whereas 10 CHF patients received one dose (4 mg) in an open study. Each variable was determined before and 6-12 times after drug intake. E (% variations from baseline) were individually related to C (ng ml(-1)) by the Hill model E=Emax x Cgamma/(CE50gamma + Cgamma). When data showed a hysteresis loop, an effect compartment was used. RESULTS: (means+/-s.d.) In HV, relationships between C and E were direct whereas in CHF patients, they showed hysteresis loops with optimal k(e0) values of 0.13 +/- 0.16 and 0.13 +/- 0.07 h(-1) for PCEA and BVR, respectively. For PCEA, with Emax set to -100%, CE50 = 1.87 +/- 0.60 and 1.36 +/- 1.33 ng ml(-1) (P = 0.34) and gamma = 0.90 +/- 0.13 and 1.11 +/- 0.47 (P = 0.23) in HV and CHF patients, respectively. For BVR, Emax= -41 +/- 14% and -60 +/- 7% (P = 0.02), CE50 = 4.95 +/- 2.62 and 1.38 +/- 0.85 ng ml(-1) (P = 0.02), and gamma = 2.25 +/- 1.54 and 3.06 +/- 1.37 (P = 0.32) in HV and CHF patients, respectively. CONCLUSIONS: Whereas concentration-effect relationships were similar in HV and CHF patients for PCEA blockade, they strongly differed for regional haemodynamics. This result probably expresses the different involvements, in HV and CHF patients, of angiotensinergic and nonangiotensinergic mechanisms in the haemodynamic effects of ACEIs.     

Protein binding of antiepileptic drugs during pregnancy, labor, and puerperium

Twenty-four epileptic women were followed-up during late pregnancy, labor, and early puerperium in order to detect possible alterations in serum protein binding of antiepileptic drugs (AEDs). The total and free concentrations of carbamazepine (CBZ), phenytoin (PHT), and valproate (VPA) in maternal serum were measured. In addition, the concentrations of albumin, alpha 1-acid glycoprotein (AGP), and free fatty acids (FFA) were also measured. Total AED concentrations during labor were influenced by changes in drug dosages; total PHT increased during the first puerperal weeks. During labor the free fraction of CBZ remained stable, whereas PHT and particularly VPA free fractions increased. This phenomenon was parallel to the increase in FFA concentration; FFA concentrations decreased again during the first days postpartum. Albumin and AGP concentrations were low during pregnancy and labor, and increased after delivery. The total umbilical CBZ and PHT concentrations were not significantly different from maternal concentrations. The total VPA concentration in umbilical serum was significantly higher than that in maternal serum. The free fraction of CBZ was higher and that of PHT and VPA lower in umbilical than in maternal serum at delivery. Umbilical cord serum had a higher albumin but a lower AGP and FFA concentration than maternal serum. The changes in PHT and particularly VPA free fraction associated with changes in FFA concentration should be considered when assessing the total concentration of these drugs in maternal and umbilical serum.     

Oxaprozin pharmacokinetics in patients with congestive heart failure

12 patients aged 26-71 years with stable, compensated congestive heart failure (CHF) and 12 healthy controls matched for age, sex, height, weight, and serum albumin, received a 1200-mg oral dose of the nonsteroidal antiinflammatory agent 4,5-diphenyl-2-oxazolepropionic acid (oxaprozin). Serum oxaprozin levels were measured by high pressure liquid chromatography during the next 14 days. Oxaprozin elimination half-life was not different between controls and CHF patients (63 vs 69 h), but peak serum levels were lower (79 vs 63 micrograms/ml, p less than 0.01), apparent volume of distribution was larger (0.22 vs 0.29 l/kg, p less than 0.05) and clearance tended to be higher, although not significantly so, (0.042 vs 0.053 ml/min/kg) in CHF patients. These differences might have been due to reduced serum protein binding (increased free fraction) in CHF patients (0.25 vs 0.44% unbound, p less than 0.1). After correction for individual values of free fraction, groups did not differ in peak free oxaprozin serum levels (0.20 vs 0.26 micrograms/ml), unbound volume of distribution (92 vs 83 l/kg), or unbound clearance (17.5 vs 15.0 ml/min/kg). Thus protein binding of oxaprozin in the present study was reduced in CHF due either to the underlying disease or to the concurrent medications. This in turn caused reciprocal reduction in total (free plus bound) oxaprozin levels and elevated estimates of volume of distribution and clearance. Although protein binding is altered, CHF causes no significant alteration in distribution of free oxaprozin nor free clearance of oxaprozin, which is accomplished by a combination of oxidation and conjugation.     

Reversible binding of the novel anti-tumour agent 5,6-dimethylxanthenone-4-acetic acid to plasma proteins and its distribution into blood cells in various species

The plasma protein binding and distribution in blood cells of the novel anti-tumour agent 5,6-dimethylxanthenone-4-acetic acid (DMXAA) has been investigated in-vitro using filtration and an HPLC method to measure DMXAA. DMXAA (500 microM) was extensively bound in plasma from all species with an unbound fraction (fu) of 4.61+/-1.10 (mouse), 2.59+/-0.32 (rat), 2.02+/-0.48 (rabbit) and 2.07+/-0.23% (human). The binding was concentration dependent with DMXAA concentrations > or = 1,000 microM markedly increasing the fu in the plasma from all species. The estimated number of binding sites in plasma were 2.4+/-0.2 (mouse), 1.7+/-0.2 (rat), 0.8+/-0.1 (rabbit) and 2.1+/- 0.2 (human). The major binding protein in human plasma was albumin, with negligible binding to gamma-globulin and alpha1-acid glycoprotein. There was a significant linear relationship between the bound:free DMXAA concentration ratio (Cb/Cu) and albumin concentration in human serum albumin solution (r = 0.955; P < 0.05) and in healthy human plasma (r = 0.998; P< 0.05), but not in plasma from cancer patients (n = 5), nor across species. In cancer patients (n = 5) DMXAA had a significantly higher (P < 0.05) fu (4.60+/- 0.42%) compared with healthy human plasma (2.07+/-0.23%). In human plasma, the fu of DMXAA (500 microM) was significantly reduced by 500 microM diazepam (P < 0.05), but not by warfarin, phenylbutazone, salicylic acid, ibuprofen or clofibric acid at that concentration. DMXAA significantly reduced the binding of dansylsarcosine (a Site-II binder) to HSA, but significantly increased the binding of dansylamide (a Site-I binder). Within species, the blood:plasma concentration ratio (CBL/CP) of DMXAA was relatively constant (mouse, 0.581+/-0.005; rat, 0.667+/-0.025; rabbit, 0.637+/-0.019; human, 0.673+/-0.103) over the range 50-1000 microM, but increased significantly at DMXAA concentrations > 1000 microM in all species except the rabbit. These results indicate that significant alterations in DMXAA plasma binding and distribution into blood cells occur with increasing concentrations of DMXAA in all species, and also that significant interspecies differences exist. It would be more appropriate to compare plasma unbound concentrations when assessing DMXAA exposure in cancer patients or when extrapolating across species.     

Plasma protein binding of azapropazone in patients with kidney and liver disease.

1 The free fraction of azapropazone in the plasma of 37 healthy volunteers ranged from 0.0027 to 0.0070 (0.0044 +/- 0.0009, mean +/- s.d.). The principal binding protein was found to be albumin. 2 In 27 patients with various degrees of renal failure the free fraction values of azapropazone were markedly enhanced (0.0260 +/- 0.0239, mean +/- s.d.) and increased more than tenfold in some patients. There was a weak correlation (r = 0.46, P less than 0.05) between the free fraction and the clearance of endogenous creatinine. Such correlation was not found for serum creatinine, serum albumin, serum uric acid and serum urea nitrogen. 3 In 32 patients with chronic liver disease the free fraction values of azapropazone were also markedly higher (0.0210 +/- 0.0242, mean +/- s.d.) than in healthy subjects. There were statistical significant correlation between free fraction values and the prothrombin complex activity in the plasma (r = 0.40, P less than 0.05) and the total bilirubin concentration in the plasma (r = 0.90, P less than 0.001), respectively. Such correlation was not found for serum albumin, serum glutamic oxalacetic transaminase, serum gamma-glutamyl transpeptidase and serum alkaline phosphatase. 4 In patients with kidney and liver disease the free fraction values of azapropazone correlated well with those of the anticoagulant drug phenprocoumon (r = 0.93, P less than 0.001). However, the binding of the latter drug was less impaired. Bilirubin, when added in vitro, displaced both drugs from plasma proteins but this displacing effect was much smaller than the binding changes observed in patients with liver disease. 5 Kidney and liver disease caused a marked impairment of the plasma protein binding of azapropazone. In patients with kidney disease the degree of impairment of azapropazone binding cannot or only poorly (creatinine clearance) be predicted from the biochemical parameters of kidney function whereas in patients with chronic liver disease the total bilirubin concentration in the plasma may serve as an index of the binding defect.     

Serum, tear and salivary concentrations of methotrexate in man.

1. Methotrexate handling has been studied in four patients with psoriasis and eleven patients with neoplastic disease. 2. Methotrexate levels in serum, tears and saliva were measured by radioimmunoassay while protein binding studies were performed by continuous ultrafiltration. 3. There was a close correlation between methotrexate concentrations in tears and serum (P less than 0.001, r = 0.714). Parotid salivary and serum methotrexate levels were similarly correlated (P less than 0.001, r = 0.557) but not mixed salivary and serum levels (P greater than 0.1, r = 0.232). 4. The mean protein binding was 95.11% +/- 2.26 (s.d.) while the ratio of methotrexate levels in tears to the free serum methotrexate level was 1:1.04. The corresponding parotid salivary level: free serum level ratio was 1:18.11. 5. No relationship could be determined between the methotrexate levels in tears and conjunctivitis observed in some of the patients under study.     

Pharmacokinetic interaction between imipramine and carbamazepine in patients with major depression

RATIONALE: Despite the fact that carbamazepine (CBZ) is frequently added to the existing tricyclic antidepressant (TCA) therapy, to date little is known about serum levels of pharmacologically active hydroxy metabolites of TCAs, as well as about possible changes in free (non-protein-bound) concentrations of these drugs and their metabolites during such combination treatment of depression. OBJECTIVE: The aim of this study was to evaluate the effect of CBZ on steady-state total and free serum concentrations of imipramine (IMI) and its metabolites, desipramine (DMI), 2-hydroxyimipramine and 2-hydroxydesipramnine, in depressed patients. In addition, the free and total serum concentrations of CBZ and 10,11-epoxycarbamazepine were measured. METHOD: Thirteen patients with DSM-III-R diagnosis of major depression were enrolled in the study. All patients hospitalised at the Department of Psychiatry, Collegium Medicum, Jagiellonian University were treated with IMI at a dose of 2 mg/kg per day for 3 weeks, after which CBZ at a dose of 400 mg/day was added. Steady-state serum concentrations of IMI, CBZ and their metabolites were assayed by HPLC. Free drug concentrations were measured by ultrafiltration. RESULTS: After 2 weeks of combination therapy a significant decrease in mean steady-state total serum concentrations of IMI (from 168.84 +/- 102.18 to 98.12 +/- 43.79 ng/ml) and DMI (from 293.89 +/- 171.93 to 221.85 +/- 153.21 ng/ml) was observed. Simultaneously, steady-state serum concentrations of total hydroxy metabolites and free IMI and its metabolites, measured just before and 2 weeks after CBZ were started, did not differ significantly. In consequence, a significant increase in free fraction of the parent drug was observed (3.36 +/- 3.24% vs 5.75 +/- 3.60%). Also free fraction of DMI tended to be higher after CBZ addition. CONCLUSION: CBZ affects not only the metabolism of IMI and its metabolites, but also their protein binding. Therefore, despite considerable reductions in total serum levels of IMI and DMI, but when the unchanged free fraction concentration of these compounds is maintained, a dosage elevation of IMI does not seem to be necessary after CBZ addition to TCA therapy.