In silico screening and study of novel ERK2 inhibitors using 3D QSAR, docking and molecular dynamics.

ERK2 is a dual specificity protein kinase, part of the Ras/Raf/MEK/ERK signal transduction cascade. It forms an interesting target for inhibition based on its relationship with cell proliferation and oncogenesis. A 3D QSAR pharmacophore model (Hypo1) with high correlation (r=0.938) was developed for ERK2 ATP site on the basis of experimentally known inhibitors. The model included three hydrogen bonds, and one hydrophobic site. Assessment of Hypo1 through Fisher randomization, cost analysis, leave one out method and decoy test suggested that the model can reliably detect ERK2 inhibitors. Hypo1 has been used for virtual screening of potential inhibitors from ZINC, Drug Bank, NCI, Maybridge and Chembank databases. Using Hypo1 as a query, databases have been interrogated for compounds who meet the pharmacophore features. The resulting hit compounds were subject to docking and analysis. Docking and molecular dynamics analysis showed that in order to achieve a higher potency compounds have to interact with catalytic site, glycine rich loop, Hinge region, Gatekeeper region and ATP site entrance residues. We also identified catalytic site and Glycine rich loop as important regions to bind by molecules for better potency and selectivity.

Co-amoxiclav-induced Stevens Johnson syndrome in a child.

Stevens-Johnson syndrome is an uncommon life threatening disease generally induced by drugs. Antibiotics, mainly sulphonamides, are the most involved drugs in Stevens-Johnson syndrome in children. Co-amoxiclav is a well tolerated antibiotic. It has never been reported to cause, lonely this syndrome in children. Herein, we report a co-amoxiclav-induced Stevens-Johnson syndrome occurring in an 18-month-old child. The diagnosis of SJS is often challenging in children and other possible diseases should be ruled out. The etiology of this syndrome is not yet fully understood. It is thought to be mediated by an immunologic mechanism. Management involves early identification, withdrawal of the culprit drug and rapid initiation of supportive therapies.

Insight into TPMT(∗)23 mutation mis-folding using molecular dynamics simulation and protein structure analysis.

Thiopurine S-methyltransferase (TPMT) is an important enzyme that metabolizes thiopurine drugs. This enzyme exhibits a large number of interindividual polymorphism. TPMT(∗)23 polymorphism has been reported in a few cases in the world in co-dominance with TPMT(∗)3A. The phenotype has been reported to affect enzyme activity in vivo and in vitro. Its underlying structural basis is not clarified yet. In our study, the wild type (WT) protein structure was analyzed and the amino acids bordering water channels in thiopurine sites were identified. Molecular dynamics of both the WT and TPMT(∗)23 mutation was carried out. In addition, the effects of this mutation, especially on the thiopurine site which is closed with a pincer like mechanism, were investigated. We focused on explaining how a locally occurred A167G substitution propagated through hydrogen bonds alteration to induce structural modification which affects both thiopurine and S-adenosylmethionine receptors. Finally, a genetic prediction of mutation functional consequences has been conducted confirming altered activity. An animated Interactive 3D Complement (I3DC) is available in Proteopedia at http://proteopedia.org/w/Journal:JBSD:20.

Acute pancreatitis in the course of meprobamate poisoning.

CONTEXT: We report a case of massive poisoning with meprobamate leading to acute pancreatitis. CASE REPORT: A 43-year-old patient with a history of schizophrenia and multiple suicide attempts was admitted to the intensive care unit for severe poisoning with meprobamate (voluntary ingestion of 60 g). On admission, the patient was deeply comatose with low blood pressure and hypothermia. Laboratory analysis revealed leukocytosis and high lipase and amylase serum levels. There was no eosinophilia. Abdominal computed tomography showed pancreatitis grade A. The patient was intubated and ventilated, and intravenous dopamine was infused. The patient regained consciousness and was extubated five days later. Improvement in pancreatic tests was noted several days later. The outcome was favorable. DISCUSSION: According to the Naranjo probability scale, meprobamate-induced acute pancreatitis was probable. Acute pancreatitis in meprobamate poisoning is exceptional. The pathogenesis of pancreatitis-induced meprobamate poisoning may be explained by two mechanisms: stimulation of pancreatic secretion secondary to cholinergic activation and pancreatic ductal hypertension. CONCLUSIONS: The signs of severe meprobamate toxicity are numerous including cardiovascular and central nervous symptoms. Acute pancreatitis should also be added as a possible manifestation of meprobamate poisoning.

Acetaminophen-induced cellulitis-like fixed drug eruption.

Acetaminophen is a widely used analgesic drug. Its adverse reactions are rare but severe. An 89-year-old man developed an indurated edematous and erythematous plaque on his left arm 1 day after acetaminophen ingestion. Cellulitis was suspected and antibiotictherapy was started but there was no improvement of the rash; there was a spectacular extension of the lesion with occurrence of flaccid vesicles and blisters in the affected sites. The diagnosis of generalized-bullous-fixed drug eruption induced by acetaminophen was considered especially with a reported history of a previous milder reaction occurring in the same site. Acetaminophen was withdrawn and the rash improved significantly. According to the Naranjo probability scale, the eruption experienced by the patient was probably due to acetaminophen. Clinicians should be aware of the ability of acetaminophen to induce fixed drug eruption that may clinically take several aspects and may be misdiagnosed.

Drug-induced hypoglycaemia: an update.

Drugs are the most frequent cause of hypoglycaemia in adults. Although hypoglycaemia is a well known adverse effect of antidiabetic agents, it may occasionally develop in the course of treatment with drugs used in everyday clinical practice, including NSAIDs, analgesics, antibacterials, antimalarials, antiarrhythmics, antidepressants and other miscellaneous agents. They induce hypoglycaemia by stimulating insulin release, reducing insulin clearance or interfering with glucose metabolism. Several drugs may also potentiate the hypoglycaemic effect of antidiabetic agents. Administration of these agents to individuals with diabetes mellitus is of most concern. Many of these drugs, and depending on clinical setting, may also induce hyperglycaemia. Drug-induced hepatotoxicity and nephrotoxicity may lead in certain circumstances to hypoglycaemia. Some drugs may also induce hypoglycaemia by causing pancreatitis. Drug-induced hypoglycaemia is usually mild but may be severe. Effective clinical management can be handled through awareness of this drug-induced adverse effect on blood glucose levels. Herein, we review pertinent clinical information on the incidence of drug-induced hypoglycaemia and discuss the underlying pathophysiological mechanisms, and prevention and management.

Azathioprine-induced severe cholestatic hepatitis in patient carrying TPMT*3C polymorphism.

CASE DESCRIPTION: A 40-year-old man with pemphigus foliaceus developed a jaundice and pruritus three weeks after starting azathioprine 100 mg daily. Laboratory investigations revealed a severe cholestatic hepatitis. Azathioprine-induced hepatitis was suspected. The dosage of thiopurine methyltransferase activity showed a low activity of the enzyme and the genotype of this enzyme found a TPMT*3C heterozygous mutant allele. Azathioprine was withdrawn. The icterus regressed progressively and the hepatic tests normalised slowly. The patient had no further episodes of hepatitis over a follow-up period of 6 months. CONCLUSION: Although, hematotoxicity seems to be associated with homozygous TPMT variants, a possible association between azathioprine hepatotoxicity and a TPMT*3C genotype should be investigated further.

Fatal allopurinol-induced hypersensitivity syndrome associated with pancreatic abnormalities.

Allopurinol hypersensitivity syndrome is a severe adverse reaction characterized by rash, fever, and internal organ involvement. We report a case of fatal allopurinol-induced hypersensitivity syndrome associated with acute pancreatitis.A 46-year-old man was treated by allopurinol for asymptomatic hyperuricemia. The patient developed a diffuse erythrodermic maculopapular eruption and fever. Laboratory analysis revealed cytolysis and cholestasis, amylases and lipases were highly elevated. Computed tomography scans revealed pancreatitis Grade C. The treatment of asymptomatic hyperuricemia should only be initiated when there is a clear indication to reduce the incidence and the severe consequences of allopurinol hypersensitivity syndrome.

Drug-induced hypokalaemia.

Hypokalaemia (defined as a plasma potassium concentration<3.5 mEq/L) is a common electrolyte abnormality in clinical practice. Drugs are a common cause of either asymptomatic or symptomatic hypokalaemia. Drug-induced hypokalaemia is an important problem particularly in the elderly and in patients with cardiovascular, renal or hepatic disease. Hypokalaemia can complicate the use of the drug in the therapeutic concentration range, and can also be precipitated with overdose or conditions leading to drug intoxication. Because the etiologies of hypokalaemia are numerous, the diagnosis of drug-induced hypokalaemia may be overlooked. Physicians should always pay close attention to this common side effect. Evaluation and management of a hypokalaemic patient should include a careful review of medications history to determine if a drug capable of causing or aggravating this electrolyte abnormality is present.

Captopril-induced lichen planus pemphigoides.

PURPOSE: To report a rare case of lichen planus pemphigoides (LPP) possibly induced by captopril. CASE SUMMARY: A 74-year-old woman developed pruriginous and bullous lichenoid eruption after starting captopril for hypertension. Histopathological and immunological features were consistent with the diagnosis of LPP that was managed by discontinuing captopril and corticosteroid therapy. Eight months after the cessation of oral steroid therapy, no relapse had occurred. DISCUSSION: LPP, a rare skin disorder, has been generally considered to represent a mixture of clinical, histopathological and immunological patterns of lichen planus and bullous pemphigoid. It is predominantly idiopathic. However, in rare cases it has been associated with the administration of drugs. Here we present a typical LPP related to the use of captopril. CONCLUSIONS: Clinicians should be aware of the ability of captopril to induce LPP.