Effect of Nigella sativa and Fenugreek on the Pharmacokinetics and Pharmacodynamics of Amlodipine in Hypertensive Rats

BACKGROUND

The present article is related to in-vitro and in-vivo herb-drug interaction studies.

OBJECTIVES

This study aimed to investigate the effect of Nigella sativa and fenugreek on the pharmacodynamics and pharmacokinetics of amlodipine.

METHOD

Hypertensive rats of group-I were treated with amlodipine and rats of group-II and III were treated with N. sativa, and N. sativa + amlodipine and fenugreek, and fenugreek + amlodipine, respectively. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean blood pressure (MBP) of group-I, II and III rats were measured by the "tail-cuff system".

RESULTS

N. sativa, as well as fenugreek, reduced the SBP, DBP and MBP. Simultaneously, administration of fenugreek + amlodipine or N. sativa + amlodipine showed better control of BP. Individually, fenugreek, as well as N. sativa, showed a surprising reduction in the heart rate. There was no remarkable effect of any of these two herbs on Cmax, AUC0-t, Kel, and terminal elimination half-life of amlodipine, but fenugreek altered the Tmax of amlodipine significantly, from 2 ± 1.2h in control to 7.2 ± 1.7h in fenugreek treated group, probably by delaying the absorption.

CONCLUSION

Results of pharmacodynamics and pharmacokinetics studies suggested that simultaneous administration of fenugreek or N. sativa with amlodipine improved the pharmacological response of amlodipine in hypertensive rats, though there was no remarkable change in pharmacokinetic parameters (Cmax, Kel, elimination t1/2, and AUC0-t).

Pharmacogenomics of amlodipine and hydrochlorothiazide therapy and the quest for improved control of hypertension: a mini review

Blood pressure (BP) is a complex trait that is regulated by multiple physiological pathways and include but is not limited to extracellular fluid volume homeostasis, cardiac contractility, and vascular tone through renal, neural, or endocrine systems. Uncontrolled hypertension (HTN) has been associated with an increased mortality risk. Therefore, understanding the genetics that underpins and influence BP regulation will have a major impact on public health. Moreover, uncontrolled HTN has been linked to inter-individual variation in the drugs’ response and this has been associated with an individual’s genetics architecture. However, the identification of candidate genes that underpin the genetic basis of HTN remains a major challenge. To date, few variants associated with inter-individual BP regulation have been identified and replicated. Research in this field has accelerated over the past 5 years as a direct result of on-going genome-wide association studies (GWAS) and the progress in the identification of rare gene variants and mutations, epigenetic markers, and the regulatory pathways involved in the pathophysiology of BP. In this review we describe and enhance our current understanding of how genetic variants account for the observed variability in BP response in patients on first-line antihypertensive drugs, amlodipine and hydrochlorothiazide.

Use of amlodipine oral solution for the treatment of hypertension in children

Background Amlodipine is a widely used antihypertensive agent for the treatment of paediatric hypertension, but the commercially available tablets are not suitable to treat young patients, who need lower, flexible dosages and a liquid formulation. Objective To determine the pharmacokinetic properties of amlodipine and the acceptability of a standardised, extemporaneous oral solution. Method A newly developed liquid formulation of amlodipine was administered to hypertensive children between the age of 6 months and 11 years. Using a limited sampling strategy, population PK analysis was performed using nonlinear mixed effects modelling. Results Nine children, with a median age of 2.9 years (IQR 1.8-8.4), receiving stable amlodipine therapy in a median dose of 0.15 mg kg^-1 day^-1 (IQR 0.11-0.18), were switched to study medication. The population pharmacokinetic model was able to accurately predict the clearance of amlodipine in the study population. Based on the final model, clearance was reduced by 31.2% (RSE: 10%) in females. Patient reported outcomes on taste from a five-point hedonic scale were available for five patients, who scored the taste from positive to slightly negative. Conclusion The results from the PK study and the acceptability assessment show that the amlodipine oral solution presented in this study offers an appropriate treatment option for young children.

The gingival crevicular fluid levels of growth factors in patients with amlodipine-induced gingival overgrowth: A pilot study

Background

Amlodipine, calcium channel blocker (CCB), is used in the management of cardiovascular diseases which causes gingival overgrowth (GO). The growth factors may have a role in the pathogenesis of amlodipine-induced GO.

Objectives

This pilot study aimed to investigate the growth factors including transforming growth factor-b1 (TGF-b1), platelet-derived growth factor-BB (PDGF-BB), and basic fibroblast growth factor (bFGF) in gingival crevicular fluid (GCF) of patients with amlodipine-induced GO and compare with of healthy subjects.

Methods

GCF samples were collected from 56 sites presenting GO (GO + group) and from 38 sites not presenting GO (GO- group) of 5 patients using amlodipine for more than one year, and from 45 sites (control group) of 5 healthy subjects. The levels of TGF-b1, PDGF-BB, and bFGF were determined by using ELISA kits.

Results

The mean concentration of TGF-b1 in GCF samples of GO + group (9.50 ± 7.30 ng/ml) was higher than both GO- group (2.07 ± 0.50 ng/ml) and control group (2.74 ± 1.01 ng/ml) (P = 0.014). No significant difference was found among the groups in the GCF levels of PDGF-BB (P = 0.767). bFGF was detected in only 33% of the sites from patients.

Conclusion

These preliminary results suggest that TGF-b1 may play a crucial role in the pathogenesis of amlodipine-induced GO.

A rare cause of severe Cushing's syndrome

SUMMARY

Ectopic adrenocorticotropic hormone (ACTH) production is an uncommon cause of Cushing's syndrome and, rarely, the source can be a phaeochromocytoma. A 55-year-old man presented following an episode of presumed gastroenteritis with vomiting and general malaise. Further episodes of diarrhoea, joint pains and palpitations followed. On examination, he was hypertensive with no clinical features to suggest hypercortisolaemia. He was subsequently found to have raised plasma normetanephrines of 3.98 nmol/L (NR <0.71) and metanephrines of 0.69 nmol/L (NR <0.36). An adrenal CT showed a 3.8 cm right adrenal nodule, which was not MIBG-avid but was clinically and biochemically consistent with a phaeochromocytoma. He was started on alpha blockade and referred for right adrenalectomy. Four weeks later, on the day of admission for adrenalectomy, profound hypokalaemia was noted (serum potassium 2.0 mmol/L) with non-specific ST-segment ECG changes. He was also diagnosed with new-onset diabetes mellitus (capillary blood glucose of 28 mmol/L). He reported to have gained weight and his skin had become darker over the course of the last 4 weeks. Given these findings, he underwent overnight dexamethasone suppression testing, which showed a non-suppressed serum cortisol of 1099 nmol/L. Baseline serum ACTH was 273 ng/L. A preliminary diagnosis of ectopic ACTH secretion from the known right-sided phaeochromocytoma was made and he was started on metyrapone and insulin. Surgery was postponed for 4 weeks. Following uncomplicated laparoscopic adrenalectomy, the patient recovered with full resolution of symptoms.

LEARNING POINTS

Phaeochromocytomas are a rare source of ectopic ACTH secretion. A high clinical index of suspicion is therefore required to make the diagnosis. Ectopic ACTH secretion from a phaeochromocytoma can rapidly progress to severe Cushing's syndrome, thus complicating tumour removal. Removal of the primary tumour often leads to full recovery. The limited literature suggests that the presence of ectopic Cushing's syndrome does not appear to have any long-term prognostic implications.

Ninjurin-1 upregulated by TNFα receptor 1 stimulates monocyte adhesion to human TNFα-activated endothelial cells; benefic effects of amlodipine

AIMS

The objectives of the present study were to investigate the mechanisms of Ninj-1 regulation in TNFα-activated human endothelial cells (HEC), and to test if Amlodipine (AML) ameliorates the inflammatory stress by decreasing Ninj-1 expression.

MAIN METHODS

TNFα-activated HEC with/without AML (0.1 μM and 1 μM) were used. TNFα-receptor 1 (TNFR1) was silenced and inhibitors for oxidative stress (N-acetyl cysteine), endoplasmic reticulum stress (salubrinal, 4-phenyl butyric acid), or NF-kB (Bay 11-7085) and p38 MAPK (SB203580) were used. Levels of Ninj-1, TNFR1, monocyte adhesion, endoplasmic reticulum stress (ERS) sensors, NADPH oxidase- and mitochondria-derived oxidative species were evaluated.

KEY FINDINGS

The novel findings that we report here are: (i) silencing the endothelial TNFR1 leads to decreased Ninj-1 expression and diminished monocyte adhesion; (ii) increased oxidative stress, ERS and NF-kB activation enhance Ninj-1 expression and monocyte adhesion; (iii) up-regulation of endothelial Ninj-1 expression stimulates monocytes adhesion to TNFα - activated HEC; (iv) AML diminishes monocyte adhesion by reducing Ninj-1 expression through mechanisms involving the decrease of NADPH oxidase and mitochondria-dependent oxidative stress, ERS and NF-kB. In addition, AML alleviates apoptosis by reducing the pro-apoptotic CHOP expression and re-establishing the mitochondrial transmembrane potential.

SIGNIFICANCE

The results of the present study suggest that Ninj-1 and the proteins involved in its regulation can be considered therapeutic targets for the alleviation of inflammation- dependent disorders. In addition, we demonstrate that some of the benefic effects of AML can be achieved through regulation of Ninj-1.

Effect of amlodipine on blood flow of preovulatory follicle in women with clomiphene resistant polycystic ovaries: a randomized controlled trial

OBJECTIVE

To detect whether amlodipine could increase pre-ovulatory follicular blood flow, thus enhancing ovulation and creating a better chance of conception in women with PCOS.

METHODS

165 women were screened of which 124 were qualified and women were equally randomized to 62 receiving clomiphene citrate and amlodipine and 62 receiving clomiphene citrate and placebo. The primary outcome was to detect if amlodipine can improve pre-ovulatory follicle blood flow studied by colour and power Doppler Pulsatility index of ovarian arteries, with drug administration. The secondary outcomes were endometrial thickness and clinical pregnancy.

RESULTS

The mean value of the ovarian arteries Pulsatility Index was significantly lower in the amlodipine group when compared to those of the placebo group (1.36 and 1.82, respectively, with P value 0.002). Mean endometrial thickness, for all women in both groups, on the day of detecting a mature follicle was significantly higher in the amlodipine group compared to the placebo group (8.99 and 7.0, respectively, with P value 0.003), and clinical pregnancy increased from 11% to 37% in the amlodipine group compared to the placebo group.

CONCLUSION

Amlodipine improves ovarian blood flow and increases the chances of conception.

TRIAL REGISTRATION

Pan African Clinical Trial Registry (http://www.pactr.org). Trial No: PAC TR201708002485292.

Investigation of complexation of amlodipine with lysozyme and its effect on lysozyme crystal growth

Lysozyme (LYZ) is a model protein frequently employed to study interaction with drugs and to understand the crystallization process of protein due to its small size and rapid crystallization behavior. Studies related to drug interaction and complexation with proteins will be significantly benefited if a suitable drug-lysozyme crystal is available. This can further aid in the understanding of the mechanism of nucleation, growth and the formation of drug-lysozyme complex. In the present study, amlodipine (AMLD) complexation with LYZ has been monitored, along with its effect on lysozyme crystallization. Different spectroscopic methods have been employed to monitor the nature of complexation, binding mode and changes in helix after interaction with AMLD. The absorbance and fluorescence spectroscopic measurement indicated the probability of a ground state complex between LYZ and AMLD. Further, the temperature dependent fluorescence studies showed an increase in binding constant with temperature, suggesting the static quenching mechanism involved in complex formation due to hydrophobic interactions. CD, FTIR, DLS and DSC techniques confirm the probability of changes in the tertiary structure of protein. Molecular docking was applied to investigate the interaction of amino acid residues of LYZ with AMLD. It was found that the complex formation is spontaneous and the ΔG value obtained (-21. 76 kJ/mol) very well matched with temperature dependent fluorescence study (-24.91 kJ/mol). Crystallization of LYZ was performed with different concentration ranges of AMLD to get a clear picture of its interference on the process. The time required for crystallization of AMLD-LYZ complex and the observed structure of crystal indicates that AMLD influences lysozyme crystallization process by changing the nature of nucleation and rate of crystal growth.

Evaluation of pharmacokinetics and safety with bioequivalence of Amlodipine in healthy Chinese volunteers: Bioequivalence Study Findings

Background and Objective

Amlodipine, a main series of L‐type calcium channel blockers (CCBs), exerts potent antihypertensive effects. The aim of this trial was to explore the pharmacokinetics (PK) and safety with bioequivalence of orally administered Amlodipine provided by two sponsors in healthy volunteers (HVs).

Methods

Two separate randomized, open‐label, single‐dose, crossover‐design studies were conducted: a fasting study (n = 24) and a fed study (n = 24). In each study, HVs were randomized to Fangming Pharmaceutical Group (Test, T) followed by NORVASC^® (Reference, R), or vice versa. Each study subject received a 5‐mg Amlodipine tablet with a 15‐day washout. The plasma concentrations of Amlodipine were measured using a LC‐MS/MS method, and PK parameters were determined by noncompartmental model.

Results

Forty‐eight healthy volunteers were enrolled. And overall demographics were as follows: the fasting study: female (n = 16/24), age (18‐54 years), weight (47‐76 kg), and BMI (19.5‐26.0). The fed study: female (n = 16/24), age (20‐49 years), weight (45.5‐69 kg), and BMI (19.1‐25.0). All PK endpoints met the pre‐specific criteria for PK equivalence. In fasting subjects, the maximum plasma concentration (C_max) was 3.881 ± 0.982 ng/mL at 6 hours (median) of sponsor T, and 4.042 ± 1.147 ng/mL at 6 hours (median) of sponsor R. In fed subjects, C_max was 3.312 ± 0.789 ng/mL at 6 hours (median) of sponsor T, and 3.392 ± 0.902 ng/mL at 5 hours (median) of sponsor R. Both fasting and fed studies achieved a plausible bioequivalence.

Conclusions

Amlodipine is well tolerated and have a favorable safety profile. The observed adverse events were mild (the severity was assessed according to the Common Terminology Criteria for Adverse Events [version CTCAE4.03]) and all of them were recovered without severe sequences. And the bioequivalence is achieved under fasting and fed conditions, supporting the demonstration of biosimilarity.

Simultaneous estimation of amlodipine and atorvastatin by micelle-augmented first derivative synchronous spectrofluorimetry and multivariate analysis

Five Selective, rapid and sensitive spectrofluorimetric methods were performed in this study for the simultaneous estimation of amlodipine besylate (AML) and atorvastatin (ATR) in their binary mixtures and combination polypills that are used for management of cardiovascular conditions. The first method depends on micelle-enhanced first derivative synchronous fluorimetric analysis (method I) and the other four methods are multivariate analysis techniques based on the use of factor-based calibration prediction methods comprising partial least squares (PLS), Principal Component Regression (PCR), genetic algorithm PLS (GA-PLS) and genetic algorithm PCR (GA-PCR). The synchronous fluorescence spectra of the solutions were measured at a constant wavelength difference; Δλ = 100 nm. The magnitudes of the peaks of the first derivative spectra (1D) were measured at 292 nm and 387 nm for ATR, and AML correspondingly. The multivariate models were constructed utilizing fifteen mixtures as a calibration set and ten mixtures as a validation set. The linearity of all the methods was in the concentration ranges of (0.1-4.0 μg mL^-1, 0.4-10.0 μg mL^-1) for AML and ATR, correspondingly. Statistical analysis revealed no significant difference between the proposed methods and the reference method. The validity of the proposed methods allows their suitability for quality control work. All the analysis settings were optimized and all the suggested procedures were applied productively for the determination of both drugs in synthetic mixtures, validation set, and combination polypills.

Severe Amlodipine Toxicity: A Case Rescued with Extracorporeal Membrane Oxygenation

Amlodipine is a widely prescribed drugs for the management of hypertension. Its toxicity is associated with severe myocardial depression and refractory hypotension. We present a case of a 28-year-old female known case of seizure disorder and depression who got admitted to our hospital with a history of consumption of 80 tablets of 5 mg amlodipine (total 400 mg). Patient presented to our hospital after 23 hours following consumption of the drug. Patient was managed in the intensive care unit (ICU) with mechanical ventilation support and intravenous infusion of noradrenalin, adrenalin, insulin-dextrose, and calcium gluconate. Due to refractory hypotension, venoarterial extracorporeal membrane oxygenation (VA-ECMO) was initiated on the same day. Patient was successfully managed and discharged home on the 8th day. This report highlights a rare case of a massive amlodipine overdose (400 mg) and ECMO as a rescue therapy.

How to cite this article

Sutar A, Venkategowda PM, Murthy A, Chikkaswamy SB. Severe Amlodipine Toxicity: A Case Rescued with Extracorporeal Membrane Oxygenation. Indian J Crit Care Med 2020;24(5):365-366.

Primary aldosteronism in Klinefelter's syndrome: two cases

SUMMARY

Primary aldosteronism (PA) is more common than expected. Aberrant adrenal expression of luteinizing hormone (LH) receptor in patients with PA has been reported; however, its physiological role on the development of PA is still unknown. Herein, we report two unique cases of PA in patients with untreated Klinefelter's syndrome, characterized as increased serum LH, suggesting a possible contribution of the syndrome to PA development. Case 1 was a 39-year-old man with obesity and hypertension since his 20s. His plasma aldosterone concentration (PAC) and renin activity (PRA) were 220 pg/mL and 0.4 ng/mL/h, respectively. He was diagnosed as having bilateral PA by confirmatory tests and adrenal venous sampling (AVS). Klinefelter's syndrome was suspected as he showed gynecomastia and small testes, and it was confirmed on the basis of a low serum total testosterone level (57.3 ng/dL), high serum LH level (50.9 mIU/mL), and chromosome analysis. Case 2 was a 28-year-old man who had untreated Klinefelter's syndrome diagnosed in his childhood and a 2-year history of hypertension and hypokalemia. PAC and PRA were 247 pg/mL and 0.3 ng/mL/h, respectively. He was diagnosed as having a 10 mm-sized aldosterone-producing adenoma (APA) by AVS. In the APA, immunohistochemical analysis showed co-expression of LH receptor and CYP11B2. Our cases of untreated Klinefelter's syndrome complicated with PA suggest that increased serum LH levels and adipose tissues, caused by primary hypogonadism, could contribute to PA development. The possible complication of PA in hypertensive patients with Klinefelter's syndrome should be carefully considered.

LEARNING POINTS

The pathogenesis of primary aldosteronism is still unclear. Expression of luteinizing hormone receptor has been reported in aldosterone-producing adenoma. Serum luteinizing hormone, which is increased in patients with Klinefelter's syndrome, might contribute to the development of primary aldosteronism.

Compelling therapy of LVH: straight (and not-so-straight) inferences from evidence

We have read with interest the Korean Society of Hypertension guidelines for the management of hypertension and congratulate the Society for an extensive review of literature while drafting the guidelines. The guidelines indicate preferring ACE-I and CCB over diuretics in patients with left ventricle hypertrophy. However, in landmark head-to-head comparison trials, the thiazide-like diuretic chlorthalidone has been shown to be superior to ACE-I and CCB in decreasing left ventricle mass and preventing heart failure in hypertensive patients. Also, we put forth the paradoxical finding that mere regression of LVH may not always translate into reduction in risk of HF; and that the pleiotropic effects of chlorthalidone may be the explanation behind its beneficial action in HF.

Pharmacokinetic comparison between fixed-dose combination of fimasartan/amlodipine 60/10 mg and the corresponding loose combination through partial replicated crossover study in healthy subjects

Combination therapies of antihypertensive drugs are recommended in cases where hypertension is not controlled by monotherapy. This study aimed to compare the pharmacokinetics (PKs) between fixed-dose combination (FDC) of fimasartan/amlodipine 60/10 mg and the corresponding loose combination. Because of the high intra-subject variability for maximum plasma concentration (Cmax) of fimasartan, a randomized, open-label, 3×3 partial replicated crossover design was adopted. Subjects received a single dose of FDC of fimasartan/amlodipine 60/10 mg or the corresponding loose combination in each period. Blood samples for PK analysis were collected up to 48 hours for fimasartan and 144 hours for amlodipine, respectively. Geometric mean ratios (GMRs) and its 90% confidence intervals (CIs) of the FDC to the loose combination for Cmax and area under the concentration-time curve from time 0 to the last quantifiable time point (AUClast) were calculated. Sixty healthy subjects were randomized, and 57 subjects completed the study. The concentration-time profiles of fimasartan and amlodipine were similar between the FDC and loose combination. The GMRs (90% CIs) of the FDC to the loose combination for Cmax and AUClast were 1.0440 (0.9202-1.1844) and 1.0412 (0.9775-1.1090) for fimasartan, and 1.0430 (1.0156-1.0711) and 1.0339 (1.0055-1.0631) for amlodipine, respectively. The GMRs and its 90% CIs for Cmax and AUClast of fimasartan and amlodipine were included not only in the scaled bioequivalence criteria but also in the conventional bioequivalence criteria. In conclusion, FDC of fimasartan/amlodipine 60/10 mg showed comparable PK profiles with the corresponding loose combination, which suggests their bioequivalence.

A Case Report of a Gingival Plasma Cell Granuloma in a Patient on Antihypertensive Therapy: Diagnostic Enigma

The aim of the present report was to discuss a unique case of gingival plasma cell granuloma (PCG) in a hypertensive patient on Amlodipine therapy. Also, we attempt to emphasize the importance of considering primary and advance investigations before making a definite diagnosis. PCG is an extremely rare, reactive, non-neoplastic lesion characterized by the predominance of polyclonal plasma cells. Drug-induced gingival overgrowth is a known side effect of Amlodipine. A hypertensive 60-year-old female patient reported with a chief complaint of swollen gums and discomfort in the upper front teeth region. A provisional diagnosis of Amlodipine-induced gingival overgrowth, combined gingival overgrowth, and fibroma was suggested. Surprisingly, histopathology revealed it to be a plasma cell lesion which was confirmed by advanced investigations, thereby establishing a confirmatory diagnosis of PCG.

Somatostatin analog challenge test in the pre-surgical management of ACTH-secreting pheochromocytoma

SUMMARY

ACTH-secreting pheochromocytoma is a very rare cause of Cushing's syndrome, with a high morbidity and mortality risk due to both cortisol and catecholamines excess. We report the case of a 45-year-old female patient with a 3 cm, high-density, left adrenal mass, diagnosed as an ACTH-secreting pheochromocytoma. The biochemical sensitivity of the tumor to somatostatin analogues was tested by a 100 μg s.c. octreotide administration, which led to an ACTH and cortisol reduction of 50 and 25% respectively. In addition to alpha and beta blockers, preoperative approach to laparoscopic adrenalectomy included octreotide, a somatostatin analogue, together with ketoconazole, in order to achieve an adequate pre-surgical control of cortisol release. Histopathological assessment confirmed an ACTH-secreting pheochromocytoma expressing type 2 and 5 somatostatin receptors (SSTR-2 and -5).

LEARNING POINTS

ACTH-secreting pheochromocytomas represent a rare and severe condition, characterized by high morbidity and mortality risk. Surgical removal of the adrenal mass is the gold standard treatment, but adequate medical therapy is required preoperatively to improve the surgical outcome and to avoid major complications. Somatostatin analogs, in addition to other medications, may represent a useful therapeutic option for the presurgical management of selected patients. In this sense, the octreotide challenge test is a useful tool to predict favorable therapeutic response to the treatment.

Synthesis, Biological Evaluation and Molecular Docking Studies of Novel Di-hydropyridine Analogs as Potent Antioxidants

AIM

The aim of this study is to synthesize, characterize and biological evaluation of 3-ethyl 5- methyl2-(2-aminoethoxy)-4-(2-chlorophenyl)-1,4-dihydropyridine-3,5-dicarboxylate derivatives.

BACKGROUND

An efficient synthesis of two series of novel carbamate and sulfonamide derivatives of amlodipine, 3-ethyl 5-methyl 2-(2-aminoethoxy)-4-(2-chlorophenyl)-1,4-dihydropyridine-3,5-dicarboxylate (amlodipine) 1 were chemical synthesized process.

MATERIALS & METHODS

In this process, various chloroformates 2(a-e) and sulfonyl chlorides 4(a-e) on reaction with 1 in the presence of N,N-dimethylpiperazine as a base in THF at 50-550 oC, the corresponding title compounds 3(a-e) and 5(a-e) in high yields. Furthermore, the compounds 3(a-e) and 5(a-e) were evaluated for antioxidant activity (DPPH method), metal chelating activity, hemolytic activity, antioxidant assay (ABTS method), cytotoxicity, molecular docking and in silico ADMET properties.

RESULTS

Results revealed that 5a, 5e, 3d, 3a and 5c exhibited high antioxidant, metal chelating activities, but 5a, 5e and 3d exhibited low activity. The molecular docking studies and ADMET of suggested ligands showed the best binding energies and non-toxic properties.

CONCLUSION

The present in silico and in vitro evaluations suggested that these dihydropyridine derivatives act as potent antioxidants and chelating agents which may be useful in treating metals induced oxidative stress associated diseases.

POEMS syndrome: a rare cause of adrenal insufficiency in a young male

SUMMARY

POEMS syndrome (Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal protein and Skin changes) is a rare multisystemic disease. Clinical presentation is variable, the only mandatory criteria being polyneuropathy and monoclonal gammapathy in association with one major and one minor criterion. Primary adrenal insufficiency is rarely reported. We describe a case of a 33-year-old patient, in whom the presenting symptoms were mandibular mass, chronic sensory-motor peripheral polyneuropathy and adrenal insufficiency. The laboratory evaluation revealed thrombocytosis, severe hyperkalemia with normal renal function, normal protein electrophoresis and negative serum immunofixation for monoclonal protein. Endocrinologic laboratory work-up confirmed Addison's disease and revealed subclinical primary hypothyroidism. Thoracic abdominal CT showed hepatosplenomegaly, multiple sclerotic lesions in thoracic vertebra and ribs. The histopathologic examination of the mandibular mass was nondiagnostic. Bone marrow biopsy revealed plasma cell dyscrasia and confirmed POEMS syndrome. Axillary lymphadenopathy biopsy: Castleman's disease. Gluco-mineralocorticoid substitution and levothyroxine therapy were started with clinical improvement. Autologous hematopoietic cell transplantation (HCT) was planned, cyclophosphamide induction was started. Meanwhile the patient suffered two ischemic strokes which resulted in aphasia and hemiparesis. Cerebral angiography revealed vascular lesions compatible with vasculitis and stenosis of two cerebral arteries. The patient deceased 14 months after the diagnosis. The young age at presentation, multiplicity of manifestations and difficulties in investigation along with the absence of serum monoclonal protein made the diagnosis challenging. We report this case to highlight the need to consider POEMS syndrome in differential diagnosis of peripheral neuropathy in association with endocrine abnormalities even in young patients.

LEARNING POINTS

POEMS syndrome is considered a 'low tumor burden disease' and the monoclonal protein in 15% of cases is not found by immunofixation. Neuropathy is the dominant characteristic of POEMS syndrome and it is peripheral, ascending, symmetric and affecting both sensation and motor function. Endocrinopathies are a frequent feature of POEMS syndrome, but the cause is unknown. The most common endocrinopathies are hypogonadism, primary hypothyroidism and abnormalities in glucose metabolism. There is no standard therapy; however, patients with disseminated bone marrow involvement are treated with chemotherapy with or without HCT.

Relationships between endogenous CYP3A markers and plasma amlodipine exposure and metabolism in early postpartum and non-peripartum women with hypertension

OBJECTIVE

This study aimed to evaluate the relationship between endogenous CYP3A markers and plasma amlodipine (AML) exposure and metabolism parameters in early postpartum and non-peripartum women.

METHODS

Twenty-four AML-treated early postpartum women with hypertensive disorders of pregnancy and 30 non-peripartum women with essential hypertension were enrolled. Blood samples for determination of CYP3A markers including total cholesterol-adjusted 4β-hydroxycholesterol (4β-OHC/TC), 25-hydroxyvitamin D (25-OHD), and AML and its metabolites in plasma were collected at 24 h after the AML treatment.

RESULTS

The plasma 4β-OHC/TC in postpartum women was higher than that in non-peripartum women, while the plasma 25-OHD was lower. The postpartum women had a lower plasma AML concentration and its metabolic ratio was higher. The plasma 4β-OHC/TC decreased as the number of days post-delivery increased. The plasma AML concentration increased as the number of days post-delivery increased, while the metabolic ratio of AML declined slightly. Tendency toward negative correlations between the plasma 4β-OHC/TC but not 25-OHD, and AML concentration were observed in both postpartum and non-peripartum women. In both groups, the plasma 4β-OHC/TC was correlated with the metabolic ratio of AML.

CONCLUSIONS

The early postpartum women had higher plasma 4β-OHC and AML metabolism. The plasma 4β-OHC had positive relationships with amlodipine metabolism in both women groups. AML metabolism and plasma 4β-OHC may be useful as CYP3A markers in early postpartum and non-peripartum women.

Leukocytoclastic vasculitis: An uncommon adverse effect of a common drug

A hypertensive elderly male on amlodipine presented with a palpable purpuric rash on both legs followed by shoulder, buttocks, and back with foot ulcer, which was found to be leukocytoclastic vasculitis on skin biopsy. The patient recovered completely on discontinuation of amlodipine and short-term steroid.

Pharmacokinetic Drug Interactions Between Amlodipine, Valsartan, and Rosuvastatin in Healthy Volunteers

INTRODUCTION

Amlodipine, valsartan, and rosuvastatin are among the medications widely coadministered for the treatment of hyperlipidemia accompanied by hypertension. The aim of this study was to investigate the possible pharmacokinetic drug-drug interactions between amlodipine, valsartan, and rosuvastatin in healthy Korean male volunteers.

METHODS

In this phase 1, open-label, multiple-dose, two-part, two-period, fixed-sequence study, the enrolled subjects were randomized into two parts (A and B). In part A (n = 32), each subject received one fixed-dose combination (FDC) tablet of amlodipine/valsartan 10 mg/160 mg alone for 10 consecutive days in period I, and the same FDC for 10 days with concomitant 7-day administration of 20 mg rosuvastatin in period II. In part B (n = 25), each subject received rosuvastatin alone for 7 days in period I, and the FDC for 10 days with concomitant 7-day administration of rosuvastatin in period II. In both parts, there was a 12-day washout between periods. Serial blood samples were collected for up to 72 h for amlodipine and rosuvastatin, and for up to 48 h for valsartan after the last dose of each period. The plasma concentrations of amlodipine, valsartan, and rosuvastatin were determined by using liquid chromatography-tandem mass spectrometry.

RESULTS

Fifty-seven subjects were enrolled; 30 and 25 subjects completed part A and part B, respectively. The geometric mean ratios and 90% confidence intervals for the maximum plasma concentration at steady state (C_max,ss) and the area under the plasma concentration-time curve over the dosing interval at steady state (AUC_τ,ss) were 0.9389 (0.9029-0.9763) and 0.9316 (0.8970-0.9675) for amlodipine, 0.7698 (0.6503-0.9114) and 0.7888 (0.6943-0.8962) for valsartan, and 0.9737 (0.8312-1.1407) and 0.9596 (0.8826-1.0433) for rosuvastatin, respectively. Of the 57 subjects enrolled in this study, 10 subjects experienced 13 adverse events (AEs); no severe or serious AEs were reported.

CONCLUSION

When amlodipine, valsartan, and rosuvastatin were coadministered to healthy volunteers, the pharmacokinetic exposure to valsartan was decreased, but no change in exposure to amlodipine and rosuvastatin occurred. All treatments were well tolerated.

CLINICAL TRIAL REGISTRATION

https://cris.nih.go.kr CRIS KCT0001660.

FUNDING

KyungDong Pharmaceutical Corp. Ltd., Seoul, Republic of Korea.

Calcium Channel Blockers Possibly Delay the Elimination of Plasma Methotrexate in Patients Receiving High-Dose Methotrexate Therapy

Delayed elimination of plasma methotrexate (MTX), which leads to elevated toxicity, is often observed in patients receiving high-dose methotrexate (HD-MTX) therapy, despite of the preventive measures. In this study, we investigated the factors that delay elimination of plasma MTX in patients on HD-MTX therapy. Fifteen patients who received HD-MTX therapy (21 cycles) were classified into two groups: delayed elimination of plasma MTX (38.1%, 8/21) and normal elimination of plasma MTX (61.9%, 13/21). Patient characteristics, plasma MTX concentrations, laboratory values, and adverse reactions were compared between the two groups using Fisher's exact test. Univariate analysis showed that co-administration of calcium channel blockers was significantly associated with delayed elimination of plasma MTX (p = 0.042). This is the first report demonstrating that co-administration of calcium channel blockers may be a predictive factor of delayed elimination of plasma MTX in patients receiving HD-MTX therapy.

Bilateral pheochromocytoma after kidney transplantation in neurofibromatosis type 1

We present the case of a 25-year-old male with a history of neurofibromatosis type 1 and bilateral pheochromocytoma 4 years after kidney transplantation that was successfully treated with simultaneous bilateral posterior retroperitoneoscopic adrenalectomy. Learning points: Hypertensive patients with NF1 should always be screened for pheochromocytoma. Pheochromocytoma is rarely associated with transplantation, but it must be ruled out in patients with genetic susceptibility. Posterior retroperitoneoscopic adrenalectomy (PRA) allows more direct access to the adrenal glands, especially in patients with previous abdominal surgeries.

Amlodipine-induced gingival enlargement: A case report

Gingival enlargements (GEs) can be caused by local, systemic diseases or drugs. Three molecules can be responsible of GEs: ciclosporin, phenytoin and calcium channel blockers (CCBs). We report the case of a 56-year-old male treated by Amlodipine, a CCB, for hypertension for many years and who recently developed a severe GE affecting both mandibular and maxillary arches inducing dental malposition. The histological examination showed non-specific inflammation with a predominance of lymphocytes. Amlodipine was suspected and suspended in agreement with his physician. One month later, the enlargement significantly reduced but GE was so severe and dental malposition so marked that all the teeth but the canines were extracted. No recurrence was noted one year later. This exceptional case should encourage every practitioner to be vigilant with patient treated with CCBs and their potential side effects and consequences.

Paraganglioma presenting as stress cardiomyopathy: case report and literature review

Pheochromocytoma/paraganglioma (PPGL) are neuroendocrine tumors that can secrete catecholamines. The authors describe a challenging case who presented as stress cardiomyopathy and myocardial infarction (MI). A 76-year-old man, with a medical history of Parkinson's disease, type 2 diabetes mellitus, hypertension, dyslipidaemia and a previous inferior MI in 2001, presented to the emergency department due to chest pain, headaches and vomiting. He also reported worsening blood glucose levels and increasing constipation over the preceding weeks. BP was 185/89 mmHg (no other relevant findings). EKG had ST segment depression in leads V2-V6, T troponin was 600 ng/L (<14) and the echocardiogram showed left ventricular hypokinesia with mildly compromised systolic function. Nevertheless, he rapidly progressed to severe biventricular dysfunction. Coronary angiogram showed a 90% anterior descendent coronary artery occlusion (already present in 2001), which was treated with angioplasty/stenting. In the following days, a very labile BP profile and unexplained sinus tachycardia episodes were observed. Because of sustained severe constipation, the patient underwent an abdominal CT that revealed a retroperitoneal, heterogeneous, hypervascular mass on the right (62 × 35 mm), most likely a paraganglioma. Urinary metanephrines were increased several fold. 68Ga-DOTANOC PET-CT scan showed increased uptake in the abdominal mass (no evidence of disease elsewhere). He was started on a calcium-channel blocker and alpha blockade and underwent surgery with no major complications. Eight months after surgery, the patient has no evidence of disease. Genetic testing was negative for known germline mutations. This was a challenging diagnosis, but it was essential for adequate cardiovascular stabilization and to reduce further morbidity. Learning points: PPGL frequently produces catecholamines and can manifest with several cardiovascular syndromes, including stress cardiomyopathy and myocardial infarction. Even in the presence of coronary artery disease (CAD), PPGL should be suspected if signs or symptoms attributed to catecholamine excess are present (in this case, high blood pressure, worsening hyperglycaemia and constipation). Establishing the correct diagnosis is important for adequate treatment choice. Inodilators and mechanical support might be preferable options (if available) for cardiovascular stabilization prior to alpha blockade and surgery. Laboratory interference should be suspected irrespective of metanephrine levels, especially in the context of treated Parkinson's disease.