Calcium-Dependent Interplay of Lithium and Tricyclic Antidepressants, Amitriptyline and Desipramine, on N-methyl-D-aspartate Receptors.

The facilitated activity of N-methyl-D-aspartate receptors (NMDARs) in the central and peripheral nervous systems promotes neuropathic pain. Amitriptyline (ATL) and desipramine (DES) are tricyclic antidepressants (TCAs) whose anti-NMDAR properties contribute to their analgetic effects. At therapeutic concentrations <1 µM, these medicines inhibit NMDARs by enhancing their calcium-dependent desensitization (CDD). Li+, which suppresses the sodium−calcium exchanger (NCX) and enhances NMDAR CDD, also exhibits analgesia. Here, the effects of different [Li+]s on TCA inhibition of currents through native NMDARs in rat cortical neurons recorded by the patch-clamp technique were investigated. We demonstrated that the therapeutic [Li+]s of 0.5−1 mM cause an increase in ATL and DES IC50s of ~10 folds and ~4 folds, respectively, for the Ca2+-dependent NMDAR inhibition. The Ca2+-resistant component of NMDAR inhibition by TCAs, the open-channel block, was not affected by Li+. In agreement, clomipramine providing exclusively the NMDAR open-channel block is not sensitive to Li+. This Ca2+-dependent interplay between Li+, ATL, and DES could be determined by their competition for the same molecular target. Thus, submillimolar [Li+]s may weaken ATL and DES effects during combined therapy. The data suggest that Li+, ATL, and DES can enhance NMDAR CDD through NCX inhibition. This ability implies a drug−drug or ion−drug interaction when these medicines are used together therapeutically.

Differential tissue distribution of discrete typing units after drug combination therapy in experimental Trypanosoma cruzi mixed infection.

The aim of the present work was to evaluate the distribution of the different clones of the parasite prevailing after treatment with benznidazole (BZ) and clomipramine (CLO), in mice infected with Trypanosoma cruzi, Casibla isolate which consists of a mixture of two discrete typing units (DTUs). Albino Swiss mice were infected and treated with high and low concentrations of BZ (100 or 6.25 mg/kg), CLO (5 or 1.25 mg/kg), or the combination of both low doses (BZ6.25 + CLO1.25), during the acute phase of experimental infection. Treatment efficacy was evaluated by comparing parasitaemia, survival and tissular parasite presence. For DTUs genotyping, blood, skeletal and cardiac muscle samples were analysed by multiplex quantitative polymerase chain reaction. The combined treatment had similar outcomes to BZ6.25; BZ100 was the most effective treatment, but it failed to reach parasite clearance and produced greater histological alterations. Non-treated mice and the ones treated with monotherapies showed both DTUs while BZ6.25 + CLO1.25 treated mice showed only TcVI parasites in all the tissues studied. These findings suggest that the treatment may modify the distribution of infecting DTUs in host tissues. Coinfection with T. cruzi clones belonging to different DTUs reveals a complex scenario for the treatment of Chagas disease and search for new therapies.

Comparative effect of administration and discontinuation of sildenafil and/or clomipramine on the hepatic, cardiac and testicular tissues of male rats.

In this study, we examined the adverse consequences of prolonged treatment with sildenafil and/or clomipramine (CLO) on the hepatic, cardiac and testicular tissues of rats. Additionally, we investigated the potential effects of treatment discontinuation. To this end, 60 adult male rats were randomly assigned into six groups and were orally treated with 4.5 mg sildenafil /kg BW (SLD) and 9 mg/ kg BW (SHD), 2.25 mg CLO/kg BW (CLO), 4.5 mg sildenafil/kg BW + 2.25 mg CLO/kg BW (SLD-CLO) and 9 mg sildenafil/kg BW + 2.25 mg CLO/kg BW (SHD-CLO) while the control rats received 0.5 ml distilled water for 8 weeks. Then, five rats from each group were sacrificed and the other five rats were left untreated for another four weeks to recover from the drug treatment. Long-term administration of sildenafil and/or CLO led to oxidative stress, inflammation and structural changes in the liver, heart and testis, reduction in sperm count and motility, an increase in abnormalities, and a reduction in serum testosterone, FSH and LH levels. All tested parameters returned to the normal state following the four-week discontinuation of sildenafil. Additionally, all the alterations caused by long-term administration of CLO, SLD-CLO and SHD-CLO were significantly improved during the recovery period.

Non-extractive spectrophotometric determination of memantine HCl, clomipramine HCl and fluvoxamine maleate in pure form and in pharmaceutical products by ion-pair complex formation with rose bengal.

OBJECTIVES: The objective of this work is to develop a simple, sensitive and non-extractive spectrophotometric method for the determination of memantine HCl (MEM), clomipramine HCl (CLM) and fluvoxamine maleate (FLV). MATERIAL AND METHODS: The proposed method was based on the formation of colored ion-pair complexes between the basic nitrogen of the target drugs and rose bengal (RB) dye in a weak acidic medium. RESULTS: The formed complexes were measured at 576nm for MEM, CLM and at 575nm for FLV. The reaction conditions were optimized to obtain the maximum color intensity. Beer's law was obeyed in the range of 2-20, 1-16 and 6-30µg/mL for MEM, CLM and FLV, respectively. The limit of detection (LOD) was 0.476, 0.185, 0.806 and the limit of quantitation (LOQ) was 1.443, 0.559 and 2.443 for MEM, CLM and FLV, respectively. The composition ratio of the ion-pair complexes was found to be 1:1 as determined by Job's method. CONCLUSION: The proposed method was applied successfully for the analysis of the cited drugs in pure and dosage forms. Results of the proposed method were statistically compared with the reported methods by applying student's t- and F-tests and no significant differences were observed.

Pharmacological interaction between NSAIDS with clomipramine and risperidone in mice visceral pain.

Nonsteroidal anti-inflammatory drugs (NSAIDs) possess as primary action mechanism the inhibition of cyclooxygenases (COX-1, COX-2, and COX-3), thus producing a decreasing prostaglandin synthesis. This study was designed to evaluate whether the antinociception induced by NSAIDs could be modulated by clomipramine or risperidone using a chemical model of inflammatory acute visceral pain, the abdominal acetic acid induced a writhing test in mice. Dose-response curves, intraperitoneal, or intrathecal for the antinociceptive activity displayed by ketoprofen, piroxicam, nimesulide, parecoxib, and paracetamol were analyzed in order to obtain the ED50 of each drug. Pretreatment of mice with either clomipramine or risperidone, increased antinociceptive potency of ketoprofen, piroxicam, nimesulide, parecoxib, and paracetamol, expressed by a decrease in the values of antinociceptive ED50. The results that were obtained are in line with those where the inhibition of COXs provides a justification for most of the pharmacological actions. Nevertheless, several findings suggest other molecular mechanisms, among which may be mentioned, L-selecting shedding; inhibition of i-NOS; inhibition of NF-Kappa B; suppression metaloproteinasas; inhibition of ß2 integrin activation; activation of α2 -adrenoceptor; increase of IL-1ß; upregulation IL-6. In conclusion, the data generated in this study demonstrated that risperidone and clomipramine, separately, increase antinociceptive potency of NSAIDs in a chemical model of inflammatory acute visceral tonic pain.

Integrated Approach Reveals Role of Mitochondrial Germ-Line Mutation F18L in Respiratory Chain, Oxidative Alterations, Drug Sensitivity, and Patient Prognosis in Glioblastoma.

Glioblastoma is the most common and malignant primary brain tumour in adults, with a dismal prognosis. This is partly due to considerable inter- and intra-tumour heterogeneity. Changes in the cellular energy-producing mitochondrial respiratory chain complex (MRC) activities are a hallmark of glioblastoma relative to the normal brain, and associate with differential survival outcomes. Targeting MRC complexes with drugs can also facilitate anti-glioblastoma activity. Whether mutations in the mitochondrial DNA (mtDNA) that encode several components of the MRC contribute to these phenomena remains underexplored. We identified a germ-line mtDNA mutation (m. 14798T > C), enriched in glioblastoma relative to healthy controls, that causes an amino acid substitution F18L within the core mtDNA-encoded cytochrome b subunit of MRC complex III. F18L is predicted to alter corresponding complex III activity, and sensitivity to complex III-targeting drugs. This could in turn alter reactive oxygen species (ROS) production, cell behaviour and, consequently, patient outcomes. Here we show that, despite a heterogeneous mitochondrial background in adult glioblastoma patient biopsy-derived cell cultures, the F18L substitution associates with alterations in individual MRC complex activities, in particular a 75% increase in MRC complex II_III activity, and a 34% reduction in CoQ10, the natural substrate for MRC complex III, levels. Downstream characterisation of an F18L-carrier revealed an 87% increase in intra-cellular ROS, an altered cellular distribution of mitochondrial-specific ROS, and a 64% increased sensitivity to clomipramine, a repurposed MRC complex III-targeting drug. In patients, F18L-carriers that received the current standard of care treatment had a poorer prognosis than non-carriers (373 days vs. 415 days, respectively). Single germ-line mitochondrial mutations could predispose individuals to differential prognoses, and sensitivity to mitochondrial targeted drugs. Thus, F18L, which is present in blood could serve as a useful non-invasive biomarker for the stratification of patients into prognostically relevant groups, one of which requires a lower dose of clomipramine to achieve clinical effect, thus minimising side-effects.

Blockade of voltage-dependent K+ current in rabbit coronary arterial smooth muscle cells by the tricyclic antidepressant clomipramine.

We investigated the effect of the tricyclic antidepressant clomipramine on voltage-dependent K+ (Kv) channels in native rabbit coronary arterial smooth muscle cells. Our results showed that clomipramine inhibited vascular Kv channels in a concentration-dependent manner, with an IC50 value of 8.61 ± 4.86 µM and a Hill coefficient (n) of 0.58 ± 0.07. The application of 10 µM clomipramine did not affect the activation curves of the Kv channels; however, the inactivation curves of the Kv channels were shifted toward a more negative potential. The clomipramine-induced inhibition of Kv currents was not changed by the application of train pulses (1 or 2 Hz), which demonstrated that clomipramine inhibited Kv current in a state (use)-independent manner. Pretreatment with the Kv1.5 and Kv2.1 inhibitors, DPO-1 and guangxitoxin, respectively, partially reduced the clomipramine-induced inhibition of Kv currents. Therefore, we concluded that clomipramine inhibited vascular Kv channels in a concentration-dependent, but state (use)-independent manner, regardless of its own function.

In vitro and in vivo drug combination for the treatment of Trypanosoma cruzi infection: A multivariate approach.

Combination therapies based on the available drugs have been proposed as promising therapeutic alternatives for many diseases. Clomipramine (CLO) has been found to modify the evolution of the experimental infection. The objective of this study was to evaluate the combined effect of benznidazole (BZ) and clomipramine (CLO) against different life-stages of Trypanosoma cruzi in vitro and their efficacy in a murine model. Life-stages of T. cruzi, BZ-partially-resistant (Y) strain, were incubated with BZ and CLO and isobolograms and combination index (CI) were obtained. Swiss mice were infected with trypomastigotes and different treatment schedules were performed, each of which consisted of 30 consecutive daily doses. Treatment efficacy was evaluated by comparing parasitemia, qPCR, survival and histological analysis. These results were analyzed using multivariate analysis to determine the combined effect of the drugs in vivo. CLO + BZ showed synergistic activity in vitro against the clinically relevant life-stages of T. cruzi. The most susceptible forms were the intracellular amastigotes (CI: 0.20), followed by trypomastigotes (CI: 0.60), with no toxicity upon mammalian cells. The combination of both drugs CLO (1.25 mg/kg) and BZ (6.25 mg/kg), in vivo, significantly diminished the parasitic load in blood and the mortality rate. CLO + BZ presented a similar inflammatory response in cardiac and skeletal muscle (amount of inflammatory cells) to BZ (6.25 mg/kg). Finally, the results from the principal component analysis reaffirmed that both drugs administered in combination presented higher activity compared with the individual administration in the acute experimental model.

Chronic treatment with estradiol restores depressive-like behaviors in female Wistar rats treated neonatally with clomipramine.

Neonatal administration of clomipramine (CMI) induces diverse behavioral and neurochemical alterations in adult male rats that resemble major depression disorder. However, the possible behavioral alterations in adult female rats subjected to neonatal treatment with clomipramine are unknown. Therefore, the aim of this study was to explore the effect of neonatal treatment with CMI on adult female rats in relation to locomotion and behavioral despair during the estrus cycle. Also evaluated was the effect of chronic treatment with E2 on these female CMI rats. We found no effects on spontaneous locomotor activity due to neonatal treatment with CMI, or after 21days of E2 administration. In the FST, neonatal treatment with CMI increased immobility and decreased active swimming and climbing behaviors. Influence of the ovarian cycle was detected only in relation to climbing behavior, as the rats in the MD phase displayed less climbing activity. Chronic E2 administration decreased immobility but increased only swimming in CMI rats. These results suggest that neonatal treatment with CMI induces despair-like behavior in female rats, but that chronic E2 administration generates antidepressant-like behavior by decreasing immobility and increasing swimming, perhaps through interaction with the serotonergic system.

The combination of pharmacogenetic and pharmacokinetic analyses to optimize clomipramine dosing in major depression: a case report.

WHAT IS KNOWN AND OBJECTIVE: Polymorphisms in cytochrome P450 2D6 and 2C19 can lead to interindividual differences in drug plasma concentrations, affecting clomipramine efficacy. Pharmacokinetic and pharmacogenetic analyses may improve drug therapy. CASE SUMMARY: We report the case of a depressed woman requiring higher doses than standard of clomipramine. Identification of low plasma drug levels led to extensive pharmacogenetic analyses of all genes and major functional polymorphisms reported to affect clomipramine metabolism. WHAT IS NEW AND CONCLUSION: Therapeutic drug monitoring and pharmacogenetic analyses may be useful in the investigation and optimization of clomipramine in standard-dose non-responders.

Human Mitochondrial Cytochrome b Variants Studied in Yeast: Not All Are Silent Polymorphisms.

Variations in mitochondrial DNA (mtDNA) cytochrome b (mt-cyb) are frequently found within the healthy population, but also occur within a spectrum of mitochondrial and common diseases. mt-cyb encodes the core subunit (MT-CYB) of complex III, a central component of the oxidative phosphorylation system that drives cellular energy production and homeostasis. Despite significant efforts, most mt-cyb variations identified are not matched with corresponding biochemical data, so their functional and pathogenic consequences in humans remain elusive. While human mtDNA is recalcitrant to genetic manipulation, it is possible to introduce human-associated point mutations into yeast mtDNA. Using this system, we reveal direct links between human mt-cyb variations in key catalytic domains of MT-CYB and significant changes to complex III activity or drug sensitivity. Strikingly, m.15257G>A (p.Asp171Asn) increased the sensitivity of yeast to the antimalarial drug atovaquone, and m.14798T>C (p.Phe18Leu) enhanced the sensitivity of yeast to the antidepressant drug clomipramine. We demonstrate that while a small number of mt-cyb variations had no functional effect, others have the capacity to alter complex III properties, suggesting they could play a wider role in human health and disease than previously thought. This compendium of new mt-cyb-biochemical relationships in yeast provides a resource for future investigations in humans.

Clomipramine kills Trypanosoma brucei by apoptosis.

Drug repositioning, i.e. use of existing medicals to treat a different illness, is especially rewarding for neglected tropical diseases (NTD), since in this field the pharmaceutical industry is rather reluctant to spend vast investments for drug development. NTDs afflict primarily poor populations in under-developed countries, which minimizes financial profit. Here we investigated the trypanocidal effect of clomipramine, a commercial antipsychotic drug, on Trypanosoma brucei. The data showed that this drug killed the parasite with an IC50 of about 5µM. Analysis of the involved cell death mechanism revealed furthermore an initial autophagic stress response and finally the induction of apoptosis. The latter was substantiated by a set of respective markers such as phosphatidylserine exposition, DNA degradation, loss of the inner mitochondrial membrane potential and characteristic morphological changes. Clomipramine was described as a trypanothione inhibitor, but as judged from our results it also showed DNA binding capacities and induced substantial morphological changes. We thus consider it likely that the drug induces a multifold adverse interaction with the parasite's physiology and induces stress in a way that trypanosomes cannot cope with.

Quantitative PCR and unconventional serological methods to evaluate clomipramine treatment effectiveness in experimental Trypanosoma cruzi infection.

Clomipramine (CLO), a tricyclic antidepressant drug, has been used for the treatment of mice infected with Trypanosoma cruzi. In this work we evaluated the effectiveness of CLO treatment upon T. cruzi-infected mice in the chronic phase of the experimental infection using Quantitative polymerase chain reaction (qPCR) and recombinant ELISA. Sixty Swiss albino mice were inoculated with 50 trypomastigote forms of T. cruzi (Tulahuen strain). CLO treatment consisted of 5mg/kg/day during 60days by intraperitoneal injection, beginning on day 90 post infection (p.i) when the mice presented electrocardiographic (ECG) alterations compatible with the chronic phase of the disease. The evolution of experimental infection and the treatment efficacy were studied through survival, electrocardiography, serology using a mixture and individual (1, 2, 13, 30, 36 and SAPA) recombinant proteins from epimastigotes and trypomastigotes of T. cruzi; and qPCR on days 180 and 270 p.i. CLO treatment in the chronic phase decreased the parasite load, reduced the levels of antibodies against antigen 13 throughout 270days p.i and reversed the ECG abnormalities in the treated animals, from 100% of the mice with alterations at the beginning of the treatment to only 20% of the mice with alterations by day 270 p.i. This study shows that qPCR and the use of recombinant antigens are more sensitive to evaluate the effectiveness of the treatment and proves that clomipramine may be considered as a new chemotherapy for the chronic phase of the disease.

Most antidepressant drugs are safe for patients with epilepsy at therapeutic doses: A review of the evidence.

For a long time, there has been a misconception that all antidepressant drugs have proconvulsant effects. Yet, antidepressants of the selective serotonin reuptake inhibitor (SSRI) and serotonin-norepinephrine reuptake inhibitor (SNRI) families have been not only shown to be safe when used in patients with epilepsy (PWE) but have been found to display antiepileptic properties in animal models of epilepsy. In humans randomized to SSRIs vs. a placebo for the treatment of primary major depressive episodes, the incidence of epileptic seizures was significantly lower among those treated with the antidepressants. On the other hand, SSRIs and SNRIs can display proconvulsant properties at toxic doses. This article reviews the preclinical and clinical data of antiepileptic and proconvulsant properties of these drugs and addresses special considerations to take when prescribing them for PWE.

A neonatal prolonged QT syndrome due to maternal use of oral tricyclic antidepressants.

UNLABELLED: It is known that tricyclic antidepressants induce long QT intervals associated with forms of life-threatening arrhythmia such as torsades de pointes (TdP), and these adverse effects may also occur in neonates whose mothers take tricyclic antidepressants. We report a neonatal case of prolonged QT interval and TdP caused by clomipramine that was transferred transplacentally from the mother. Administration of magnesium sulfate was effective to abolish TdP. CONCLUSION: When mothers take tricyclic antidepressants during pregnancy, their newborns should be watched carefully for drug-induced long QT syndrome and TdP. WHAT IS KNOWN: •Tricyclic antidepressant can prolong the QT interval. It may be used for depression in pregnancy. What is New: •This is the first neonatal case report of prolonged QT interval and TdP caused by clomipramine transferred transplacentally from the mother.

Intravenous Clomipramine for Treatment-Resistant Obsessive-Compulsive Disorder.

BACKGROUND: This open trial was conducted to evaluate the effectiveness of intravenous clomipramine (CMI) in refractory obsessive-compulsive disorder (OCD). METHODS: Thirty OCD poor responders to previous multiple trials of anti-obsessive medications were selected and admitted to the hospital. Severity of the illness and response to treatment were primarily assessed by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). CMI was gradually administered intravenously for one week. All patients were thereafter switched to oral CMI with a maximum dose of 225 mg/day. RESULTS: The Y-BOCS total score mean at admission was in the severe range (24-31), and dropped on discharge and follow-ups to the moderate range (16-23). At discharge, 23 patients (76.7%) had a decrease in Y-BOCS ≥ 25% and were considered responders, while only 18 (60%) were still responders at 24 weeks. No relevant persistent side effects were reported. CONCLUSION: Intravenous clomipramine could be of benefit for severe OCD cases that have not adequately responded to several therapies, including oral clomipramine.

A META-ANALYSIS OF COGNITIVE BEHAVIOR THERAPY AND MEDICATION FOR CHILD OBSESSIVE-COMPULSIVE DISORDER: MODERATORS OF TREATMENT EFFICACY, RESPONSE, AND REMISSION.

BACKGROUND: Individual randomized controlled trials (RCTs) have demonstrated the efficacy of cognitive behavioral therapy (CBT) and serotonin reuptake inhibitors (SRIs) for the treatment of youth with obsessive-compulsive disorder (OCD). Although meta-analyses have confirmed these results, there has been minimal examination of treatment moderators or an examination of treatment response and symptom/diagnostic remission for these two treatment types. The present report examined the treatment efficacy, treatment response, and symptom/diagnostic remission for youth with OCD receiving either CBT or SRIs relative to comparison conditions, and examined treatment moderators. METHOD: A comprehensive literature search identified 20 RCTs that met inclusion criteria, and produced a sample size of 507 CBT participants and 789 SRI participants. RESULTS: Random effects meta-analyses of CBT trials found large treatment effects for treatment efficacy (g = 1.21), treatment response (relative risk [RR] = 3.93), and symptom/diagnostic remission (RR = 5.40). Greater co-occurring anxiety disorders, therapeutic contact, and lower treatment attrition were associated with greater CBT effects. The number needed to treat (NNT) was three for treatment response and symptom/diagnostic remission. Random effects meta-analyses of SRI trials found a moderate treatment effect for treatment efficacy (g = 0.50), treatment response (RR = 1.80), and symptom/diagnostic remission (RR = 2.06). Greater methodological quality was associated with a lower treatment response for SRI trials. The NNT was five for treatment response and symptom/diagnostic remission. CONCLUSIONS: Findings demonstrate the treatment effects for CBT and SRIs across three important outcome metrics, and provide evidence for moderators of CBT across trials.

Reengineered tricyclic anti-cancer agents.

The phenothiazine and dibenzazepine tricyclics are potent neurotropic drugs with a documented but underutilized anti-cancer side effect. Reengineering these agents (TFP, CPZ, CIP) by replacing the basic amine with a neutral polar functional group (e.g., RTC-1, RTC-2) abrogated their CNS effects as demonstrated by in vitro pharmacological assays and in vivo behavioral models. Further optimization generated several phenothiazines and dibenzazepines with improved anti-cancer potency, exemplified by RTC-5. This new lead demonstrated efficacy against a xenograft model of an EGFR driven cancer without the neurotropic effects exhibited by the parent molecules. Its effects were attributed to concomitant negative regulation of PI3K-AKT and RAS-ERK signaling.

Dibenzosuberyl substituted polyamines and analogs of clomipramine as effective inhibitors of trypanothione reductase; molecular docking, and assessment of trypanocidal activities.

Trypanothione reductase (TR) is an enzyme critical to the maintenance of the thiol redox balance in trypanosomatids, including the genera Trypanosoma and Leishmania that are parasites responsible for several serious diseases. Analogs of clomipramine were prepared since clomipramine is reported to inhibit TR and cure mice infected with trypanosomes, however its psychotropic activity precludes its use as an anti-trypanosomal therapeutic. The clomipramine analogs contained a tricyclic dibenzosuberyl moiety. Additionally a series of polyamines with N-dibenzosuberyl substituents were prepared. All compounds studied were competitive inhibitors of TR and showed trypanocidal activities against Trypanosoma brucei in vitro. The analogs of clomipramine were poor inhibitors of TR, whereas the polyamine derivatives were effective TR inhibitors with the most potent compound, N(4),N(8)-bis(dibenzosuberyl)spermine (7), having a Ki value of 0.26µM. However, compound (7) did not prolong the lives of mice infected with trypanosomes. Analysis of docking studies indicated: the tricyclic groups of inhibitors bind at four distinct hydrophobic regions in the active site of TR; the importance of the chlorine substituent of clomipramine in binding to TR; and binding of the dibenzosuberyl groups of (7) occur at separate and distinct hydrophobic regions within the active site of TR.

Pharmacokinetics of clomipramine during pregnancy.

PURPOSE: Clomipramine is one of the drugs for depression during pregnancy; however, pharmacokinetic data of clomipramine and its active metabolite desmethylclomipramine in this vulnerable period are lacking. In this study, we describe clomipramine and desmethylclomipramine concentrations including their ratios during pregnancy. Second, we describe Center for Epidemiologic Studies Depression scale (CES-D) scores during pregnancy. METHODS: During 13 pregnancies, every trimester and 3 months after pregnancy, the clomipramine and desmethylclomipramine concentrations were measured with LC-MSMS and the severity of depression was assessed by taking the CES-D score. All concentrations used in our calculations were in fact the ratio between actual plasma concentration (µg/l) and the actual dose (mg). We compared differences in ratios between trimesters by using the Friedman test. RESULTS: Studying 12 women and 13 pregnancies, we found no changes in mean clomipramine concentrations, a statistically significant decrease in mean desmethylclomipramine concentrations (p = 0.014) and a significant decrease in the ratio of desmethylclomipramine/clomipramine mean concentrations during pregnancy (p = 0.014) compared to the post-partum period. Sub-therapeutic concentrations of clomipramine and desmethylclomipramine were found in three patients during whole pregnancy. CONCLUSIONS: The mean concentrations of the pharmacologically active metabolite of clomipramine and desmethylclomipramine changes during pregnancy, where a decrease in mean concentrations was found during pregnancy. In case of recurrent disease, we recommend to control clomipramine and its metabolite concentrations, while both are active.