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Biomedical subjects

M Asif A Siddiqui

Publications and source records attributed to M Asif A Siddiqui.

At least 19 recordsLinked to original sources
PubMed2006

Ranolazine: a review of its use in chronic stable angina pectoris.

Ranolazine (Ranexa), a piperazine derivative, is a new antianginal agent approved for the treatment of chronic stable angina pectoris for use as combination therapy when angina is not adequately controlled with other antianginal agents. While the exact mechanism of action of ranolazine is not known, its antianginal and anti-ischaemic effects do not appear to depend upon changes in blood pressure or heart rate. An extended-release (ER) oral formulation of ranolazine has been developed to facilitate twice-daily administration whilst maintaining therapeutically effective plasma concentrations. In patients with chronic stable angina, ranolazine ER monotherapy was shown to improve exercise duration at trough plasma drug concentration in a dose-dependent manner compared with placebo. The drug was effective as adjunctive therapy in patients with chronic stable angina whose condition was not controlled adequately with conventional antianginal therapy. In randomised clinical trials, ranolazine ER was well tolerated, with no overt effects on cardiovascular haemodynamics or conduction, apart from a modest increase in corrected QT (QTc) interval (but no torsades de pointes). Importantly, the efficacy and tolerability of ranolazine ER were not affected by comorbid conditions, including old age, heart failure (HF) or diabetes mellitus. Comparative trials of ranolazine ER with other antianginal agents and trials examining its effects on long-term morbidity and mortality in patients with ischaemic heart disease are required to determine with greater certainty the place of the drug in current antianginal therapy. Nevertheless, ranolazine ER may well prove to be a useful alternative and adjunct to conventional haemodynamic antianginal therapy in the treatment of chronic stable angina.

Acetanilides↗
PubMed2006

Lubiprostone.

Lubiprostone (Amitiza) is an oral bicyclic fatty acid that selectively activates type 2 chloride channels in the apical membrane of the gastrointestinal epithelium, resulting in increased fluid secretion. In two pivotal, randomised, double-blind, multicentre phase III studies in patients with chronic idiopathic constipation, the frequency of spontaneous bowel movements (SBMs) was significantly greater in patients receiving lubiprostone 24microg twice daily than in those receiving placebo at each weekly timepoint throughout both 4-week studies (p < 0.05). At week 1 in one pivotal trial, the mean frequency of SBMs in the lubiprostone group was 5.9 per week compared with 4.0 per week in the placebo group (p < 0.0001) [baseline SBMs 1.3 and 1.5 per week]. Significantly greater improvements occurred with lubiprostone than placebo in the degree of straining, stool consistency and constipation severity (where reported) in both pivotal studies (p < 0.05 for all comparisons at all timepoints). Lubiprostone was generally well tolerated in clinical trials with no reports of treatment-related serious adverse events in pivotal trials. Nausea was the most common adverse event, occurring in up to 31% of patients receiving lubiprostone.

Adult↗
PubMed2006

Darbepoetin alfa: a review of its use in the treatment of anaemia in patients with cancer receiving chemotherapy.

Darbepoetin alfa (Aranesp) is an analogue of recombinant human erythropoietin (rHuEPO) produced using recombinant DNA technology. The high number of sialic acid moieties in darbepoetin alfa results in a prolonged half-life and enhanced in vivo biological activity compared with rHuEPO (as demonstrated in animal studies) and permits a reduction in the frequency of administration. Subcutaneous darbepoetin alfa 2.25 microg/kg once weekly or 500 microg once every 3 weeks (with a provision for dose adjustments) is an effective and well tolerated erythropoietic agent in anaemic patients with cancer receiving chemotherapy. In randomised, controlled clinical trials, the drug increased haemoglobin levels and reduced the need for blood transfusions in patients with various types of nonmyeloid malignancies and also ameliorated anaemia-related fatigue, thereby improving their health-related quality of life (HR-QOL) scores. The once-every-3-weeks dosage regimen provides further convenience by offering the possibility of synchronising its administration with most chemotherapy regimens. Direct comparisons between approved dosages of darbepoetin alfa and other erythropoietic agents have not been conducted. Such comparisons would be very helpful in formulating definitive conclusions about their relative efficacy and cost effectiveness. Darbepoetin alfa provides an effective and well tolerated treatment option for the treatment of anaemia in patients with cancer receiving chemotherapy.

Anemia↗
PubMed2006

Human papillomavirus quadrivalent (types 6, 11, 16, 18) recombinant vaccine (Gardasil).

Human papillomavirus (HPV) quadrivalent recombinant vaccine is a mixture of virus-like particles derived from the L1 capsid proteins of HPV types 6, 11, 16 and 18. It is administered intramuscularly in a three-dose regimen, with the initial injection followed by subsequent doses at months 2 and 6. The vaccine is indicated for use in the prevention of cervical cancer, vulvar and vaginal precancer and cancers, precancerous lesions and genital warts associated with HPV types 6, 11, 16 or 18 infection in adolescents and young women. The quadrivalent vaccine has demonstrated good immunogenicity in young women (16-26 years) and male and female adolescents (aged 9-15 years), inducing high and persistent anti-HPV antibody titres. In a randomised phase III trial designed to bridge efficacy in young women to adolescents (using immunogenicity as a surrogate), the quadrivalent HPV vaccine in adolescents was at least as immunogenic as that in young women. In randomised, double-blind, placebo-controlled trials in >20 000 young women (aged 16-26 years), the vaccine was highly effective in preventing cervical dysplasia of any grade and external genital lesions related to HPV types 6, 11, 16 and 18 infection. These women were followed up for an average of 2 years.black triangle The vaccine was well tolerated, with injection-site reactions and fever being the most common vaccine-related adverse events.

Female↗
PubMed2006

Rivastigmine: in Parkinson's disease dementia.

Rivastigmine is a carbamate-type dual inhibitor of brain acetyl- and butyrylcholinesterases that has been evaluated in the symptomatic treatment of patients with mild to moderate dementia associated with idiopathic Parkinson's disease. Oral rivastigmine 3-12 mg/day for 24 weeks was significantly more effective than placebo in ameliorating cognitive and functional decline, including attentional deficits, in patients with Parkinson's disease dementia in a randomised, double-blind trial. The beneficial effects of rivastigmine observed in the double-blind trial were generally maintained in a 24-week extension of this study in which all patients received active treatment; placebo recipients who switched to rivastigmine also experienced improvements in their cognitive and functional symptoms at week 48. Rivastigmine appeared to be generally well tolerated, with the most common adverse events being mild to moderate in intensity and cholinergic in nature. Parkinsonian symptoms (mainly tremor) were more common in rivastigmine than placebo recipients.

Animals↗
PubMed2006

Varenicline: a review of its use as an aid to smoking cessation therapy.

Varenicline is an orally administered alpha4beta2 nicotinic acetylcholine (ACh) receptor partial agonist. It has been approved by the US FDA (Chantix) and the European Commission (Champix) for use as an aid to smoking cessation therapy. Varenicline is an effective and generally well tolerated treatment for use in smokers who want to quit. In two well designed, phase III trials, 12 weeks' treatment with varenicline was associated with significantly higher continuous abstinence rates at weeks 9-12 than placebo or bupropion sustained-release (SR). In the longer term, continuous abstinence rates for weeks 9 through 52 demonstrated that the odds of remaining abstinent were 2.7 to 3.1 times higher with 12 weeks of varenicline treatment than with placebo; the significant difference between varenicline and bupropion SR was also maintained in the longer term in one trial. Moreover, varenicline appeared to attenuate the urge to smoke, negative affect withdrawal symptoms and the reinforcing effects of smoking. Among those achieving abstinence, an additional 12 weeks of varenicline therapy helped increase the likelihood of long-term abstinence. Thus, varenicline is a valuable new agent for use as an aid to smoking cessation treatment.

Benzazepines↗
PubMed2006

Spotlight on infliximab in Crohn disease and rheumatoid arthritis.

Infliximab (Remicade) is a chimeric monoclonal antibody against tumor necrosis factor (TNF)-alpha that has shown efficacy in Crohn disease and rheumatoid arthritis with a disease-modifying activity and rapid onset of action. It is administered intravenously, generally in a schedule with initial infusions at 0, 2, and 6 weeks, followed by administration once every 8 weeks. Infliximab is effective in the treatment of patients with moderately to severely active Crohn disease with an inadequate response to other treatment options or those with fistulizing disease. In combination with methotrexate, infliximab reduced signs and symptoms and delayed disease progression in patients with active, methotrexate-refractory rheumatoid arthritis and in those with early disease. The drug was generally well tolerated. Recrudescence of tuberculosis infection and worsening of heart failure and demyelinating disease are among some of the concerns with anti-TNFalpha therapy, requiring cautious use of these agents in high-risk patients. Current data suggest that infliximab may be cost effective, especially when long-term clinical outcomes and burden of the diseases are taken into account. More robust, prospective pharmacoeconomic studies are required to better ascertain the cost effectiveness of infliximab. Direct head-to-head comparative trials of infliximab with other biological agents are not yet available and would be helpful in determining with greater certainty the place of infliximab in the management of these diseases. Nonetheless, infliximab, like other biological agents, is a valuable treatment option in patients with moderately to severely active Crohn disease (including fistulizing disease) or rheumatoid arthritis (including early disease).

Antibodies, Monoclonal↗
PubMed2006

Spotlight on darbepoetin alfa in the treatment of anemia in patients with cancer receiving chemotherapy.

Darbepoetin alfa (Aranesp) is an analog of recombinant human erythropoietin (rHuEPO) produced using recombinant DNA technology. The high number of sialic acid moieties in darbepoetin alfa results in a prolonged half-life and enhanced in vivo biologic activity compared with rHuEPO (as demonstrated in animal studies), and permits a reduction in the frequency of administration. Subcutaneous darbepoetin alfa 2.25 microg/kg once weekly or 500microg once every 3 weeks (with a provision for dosage adjustments) is an effective and well tolerated erythropoietic agent in anemic patients with cancer receiving chemotherapy. In randomized, controlled clinical trials, the drug increased hemoglobin levels and reduced the need for blood transfusions in patients with various types of nonmyeloid malignancies, and also ameliorated anemia-related fatigue, thereby improving their health-related quality of life scores. The once-every-3-weeks dosage regimen provides further convenience by offering the possibility of synchronizing its administration with most chemotherapy regimens. Direct comparisons between approved dosages of darbepoetin alfa and other erythropoietic agents have not been conducted. Such comparisons would be very helpful in formulating definitive conclusions about their relative efficacy and cost effectiveness. Darbepoetin alfa provides an effective and well tolerated treatment option for the treatment of anemia in patients with cancer receiving chemotherapy.

Journal Article↗
PubMed2006

Reteplase: a review of its use in the management of thrombotic occlusive disorders.

Reteplase (Retavase) is a plasminogen activator, mimicking endogenous tissue plasminogen activator (t-PA), a serine protease, converting plasminogen to plasmin and thereby precipitating thrombolysis. It is a third-generation recombinant form of t-PA that operates in the presence of fibrin (i.e. it is fibrin specific). Reteplase can be administered as a bolus dose (nonweight-based) rather than an infusion, which promotes rapid and safe administration. The ease of administration of this reteplase dosage regimen (two 10U bolus doses, each over 2 minutes, 30 minutes apart) is conducive to prehospital initiation of thrombolytic treatment in patients with ST-segment elevation myocardial infarction (STEMI), which reduces the time to treatment, a critical factor in improving long-term survival. In large randomized clinical trials of patients with STEMI, reteplase was superior to alteplase for coronary artery patency (according to TIMI [thrombolysis in myocardial infarction] flow) at 60 and 90 minutes, but there was no significant difference between agents for mortality rate and incidence of intracranial bleeding. The 35-day mortality rates were equivalent for reteplase and streptokinase recipients; there was reduced incidence of some cardiac events with reteplase versus streptokinase, but a greater incidence of hemorrhagic stroke. Reteplase has also shown thrombolytic efficacy (in nonapproved indications) as a catheter-directed intra-arterial or intravenous infusion for peripheral vessel occlusions, as 5-minute bolus doses (in 1U increments) for acute ischemic stroke, as a low-dose solution for occluded catheters or grafts, and as an intravenous double bolus for massive pulmonary embolism. Across studies in these indications, the incidence of bleeding complications associated with reteplase treatment appeared to be similar to that associated with other thrombolytic agents. With its efficacy, and the ease of administration of the bolus doses potentially minimizing dosage errors when treatment is administered under time pressure, reteplase is a valuable option for pre- or in-hospital thrombolytic treatment in patients with STEMI, and is a useful thrombolytic for the treatment of the other thrombotic occlusive disorders described.

Arterial Occlusive Diseases↗
PubMed2006

Spotlight on ranolazine in chronic stable angina pectoris.

Ranolazine (Ranexa), a piperazine derivative, is a new antianginal agent approved for the treatment of chronic stable angina pectoris for use as combination therapy when angina is not adequately controlled with other antianginal agents. While the exact mechanism of action of ranolazine is not known, its antianginal and anti-ischemic effects do not appear to depend upon changes in BP or heart rate. An extended-release (ER) oral formulation of ranolazine has been developed to facilitate twice-daily administration whilst maintaining therapeutically effective plasma concentrations. In patients with chronic stable angina, ranolazine ER monotherapy was shown to improve exercise duration at trough plasma drug concentration in a dose-dependent manner compared with placebo. The drug was effective as adjunctive therapy in patients with chronic stable angina whose condition was not controlled adequately with conventional antianginal therapy. In randomized clinical trials, ranolazine ER was well tolerated, with no overt effects on cardiovascular hemodynamics or conduction, apart from a modest increase in corrected QT interval (but no torsades de pointes). Importantly, the efficacy and tolerability of ranolazine ER were not affected by old age and co-morbid conditions (heart failure or diabetes mellitus). Comparative trials of ranolazine ER with other antianginal agents and trials examining its effects on long-term morbidity and mortality in patients with ischemic heart disease are required to determine with greater certainty the place of the drug in current antianginal therapy. Nevertheless, ranolazine ER may well prove to be a useful alternative and adjunct to conventional hemodynamic antianginal therapy in the treatment of chronic stable angina.

Acetanilides↗
PubMed2005

Rasagiline.

Rasagiline is a second-generation potent, irreversible and selective inhibitor of monoamine-oxidase type B (MAO-B), which has been evaluated for the treatment of Parkinson's disease. Rasagiline also possesses neuroprotective properties that are independent of its MAO inhibitory activity. Unlike selegiline, rasagiline has no amphetamine-like metabolites and its major metabolite, 1-(R)-aminoindan, has demonstrated favourable pharmacological activity in experimental studies. Rasagiline has shown significant beneficial effects as monotherapy in the treatment of early Parkinson's disease. Monotherapy with rasagiline 1 or 2 mg once daily significantly attenuated the worsening of symptoms, compared with placebo, in patients with early Parkinson's disease in a randomised, double-blind trial (n = 404). Furthermore, patients treated with rasagiline for 12 months had less functional decline than patients whose treatment was delayed for 6 months (n = 371). In patients with moderate-to-advanced disease receiving background therapy with levodopa and additional anti-parkinsonian medications (n = 1159), rasagiline 0.5 or 1 mg once daily reduced the daily 'off' time by 0.49-0.94 hours relative to that in placebo recipients in two randomised, double-blind trials. The efficacy of rasagiline 1 mg once daily was similar to entacapone 200 mg administered with each levodopa dose. Rasagiline was generally well tolerated in clinical trials as both monotherapy and when administered with other antiparkinsonian drugs. Adverse events with rasagiline were generally similar in frequency to those seen in placebo or entacapone recipients.

Biological Availability↗
PubMed2005

Enoxaparin: a review of its use as thromboprophylaxis in acutely ill, nonsurgical patients.

Enoxaparin (Clexane), Lovenox) is a low molecular weight heparin (LMWH) that has been widely used in the prevention of venous thromboembolism (VTE) in surgical patients. More recently, with the recognition of the high incidence of VTE in acutely ill medical (nonsurgical) patients, enoxaparin has been evaluated for thromboprophylaxis in this patient population. Subcutaneous enoxaparin 40 mg once daily has shown efficacy in the short-term thromboprophylaxis of VTE in nonsurgical patients with severely restricted mobility due to acute illness in well controlled clinical trials. The drug is at least similar in efficacy to unfractionated heparin (UFH) and its pharmacological profile allows once-daily administration, in contrast to the twice- or three-times-daily administration required with UFH. The tolerability profile of enoxaparin is also similar to that of UFH, except that the incidences of local haematomas and increased liver enzymes are lower with enoxaparin. The optimal duration of prophylaxis in nonsurgical patients is currently being evaluated and the results of extended prophylaxis with enoxaparin evaluated in the EXCLAIM (EXtended CLinical prophylaxis in Acutely Ill Medical patients) trial are awaited with interest. Currently, short-term enoxaparin appears to provide a cost-effective treatment alternative to UFH for VTE prophylaxis in nonsurgical patients.

Acute Disease↗
PubMed2005

Recombinant factor VIIa (Eptacog Alfa): a review of its use in congenital or acquired haemophilia and other congenital bleeding disorders.

Recombinant factor VIIa (NovoSeven) [also known as recombinant activated factor VII or eptacog alfa] is a vitamin K-dependent glycoprotein that is structurally similar to human plasma-derived factor VIIa. It is a recombinant product, manufactured using DNA biotechnology. Intravenous recombinant factor VIIa has been evaluated in the treatment of bleeding episodes and for providing haemostasis cover during surgery in patients with certain bleeding disorders. Large, well controlled trials of recombinant factor VIIa have not been performed because of the rarity of these bleeding disorders. However, the efficacy of recombinant factor VIIa has been investigated in these patients in double-blind dose-finding or noncomparative clinical trials and worldwide compassionate-use programmes. Recombinant factor VIIa is effective and generally well tolerated in patients with haemophilia A or B with inhibitors, those with acquired haemophilia or Glanzmann's thrombasthenia. Also, recombinant factor VIIa is a treatment of choice in patients with haemophilia B with high-responding inhibitors and those with factor VII deficiency. Direct head-to-head comparisons and robust pharmacoeconomic data are required to fully determine the position of recombinant factor VIIa in relation to other therapies. Importantly though, the product appears to be relatively free of antigenicity, thrombogenicity and risk of viral transmission that, in the past, have limited the utility of blood products. Given that these characteristics are important determinants of the place of a treatment in bleeding disorders, recombinant factor VIIa provides a valuable treatment alternative in patients with haemophilia with inhibitors, platelet-refractory Glanzmann's thrombasthenia or congenital factor VII deficiency.

Factor VIIa↗
PubMed2005

Pegaptanib: in exudative age-related macular degeneration.

Pegaptanib, an aptamer, is an antagonist of vascular endothelial growth factor that has shown efficacy in the treatment of patients with exudative age-related macular degeneration (AMD). In two randomised, double-masked trials in patients with exudative AMD (n=1208), the proportion of responders (those losing <15 letters of visual acuity) at 54 weeks was significantly higher in intravitreous pegaptanib 0.3 mg recipients than in those receiving sham injections (70% vs 55%; p<0.001). These trials were conducted concurrently and analysed as a single study; the treatments were given every 6 weeks for 48 weeks. The improvement in visual acuity with pegaptanib was maintained in a 1-year extension of these trials. Similar favourable results with pegaptanib 0.3 mg were seen in terms of the secondary efficacy endpoints (e.g. proportion of patients experiencing severe loss of visual acuity or legal blindness in the study eye). These vision-improving effects of pegaptanib were associated with beneficial angiographic effects. Intravitreous pegaptanib 0.3-3 mg was well tolerated with most ocular adverse events being mild-to-moderate and transient. Serious injection-related adverse events occurred in <or=1.3% of patients treated with pegaptanib. There were no systemic adverse events that could be definitely attributed to pegaptanib.

Animals↗
PubMed2005

Azacitidine: in myelodysplastic syndromes.

Azacitidine, a pyrimidine analogue, is an antineoplastic agent that acts mainly by causing hypomethylation of cytosine residues in newly replicated DNA and has shown efficacy in the treatment of myelodysplatic syndromes (MDS). In a randomised controlled trial in patients with MDS (n=191), subcutaneous azacitidine 75-100 mg/m2/day in 7-day cycles every 28 days with continuing supportive care produced a significantly higher response rate (including reductions in rate of transformation to acute myeloid leukaemia and transfusion requirements) than that seen with supportive care alone (60% vs 5%; p<0.001). Patients (n=49) who were switched from supportive care to azacitidine after 4 months also showed a 47% response rate. The clinical response in patients receiving azacitidine was associated with significant (p<or=0.015) improvements in several measures of health-related quality of life, including those assessing fatigue and physical functioning, compared with those in supportive care recipients. Given the grim prognosis of MDS patients, azacitidine was generally well tolerated, with common, but transient, myelotoxicity. Adverse events did not increase in severity or frequency during the course of the treatment.

Antimetabolites, Antineoplastic↗
PubMed2005

Palifermin: in myelotoxic therapy-induced oral mucositis.

Palifermin, a recombinant human keratinocyte growth factor (KGF), mimics the actions of endogenous KGF and has shown efficacy in the management of myelotoxic therapy-induced oral mucositis in cancer patients. In a randomised, double-blind trial in patients with haemtaological malignancies receiving conditioning radiochemotherapy before undergoing autologous stem cell transplant, intravenous palifermin 60 microg/kg/day (two 3-day cycles, administered before myelotoxic therapy and after transplant) significantly reduced the median duration (primary endpoint) [3 vs 9 days] and incidence (63% vs 98%) of WHO grade 3 or 4 oral mucositis, compared with placebo. Patient-reported outcomes also showed significant improvement with palifermin treatment, which was associated with significant reductions in healthcare resource utilisation, compared with placebo. The drug was generally well tolerated, with skin/oral toxicities, pain/arthralgias and dysaesthesia being the most common palifermin-related adverse reactions.

Animals↗
PubMed2005

Infliximab: a review of its use in Crohn's disease and rheumatoid arthritis.

Infliximab (Remicade) is a chimeric monoclonal antibody against tumour necrosis factor (TNF)-alpha that has shown efficacy in Crohn's disease and rheumatoid arthritis with a disease-modifying activity and rapid onset of action. It is administered intravenously, generally in a schedule with initial infusions at 0, 2 and 6 weeks, followed by administration once every 8 weeks. Infliximab is effective in the treatment of patients with moderately to severely active Crohn's disease with an inadequate response to other treatment options or those with fistulising disease. In combination with methotrexate, infliximab reduced signs and symptoms and delayed disease progression in patients with active, methotrexate-refractory rheumatoid arthritis and in those with early disease. The drug was generally well tolerated. Recrudescence of tuberculosis infection and worsening of heart failure and demyelinating disease are among some of the concerns with anti-TNFalpha therapy, requiring cautious use of these agents in high-risk patients. Current data suggest that infliximab may be cost effective, especially when long-term clinical outcomes and burden of the diseases are taken into account. More robust, prospective pharmaco-economic studies are required to better ascertain the cost effectiveness of infliximab. Direct head-to-head comparative trials of infliximab with other biological agents are not yet available and would be helpful in determining with greater certainty the place of infliximab in the management of these diseases. Nonetheless, infliximab, like other biological agents, is a valuable treatment option in patients with moderately to severely active Crohn's disease (including fistulising disease) or rheumatoid arthritis (including early disease).

Antibodies, Monoclonal↗