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Biomedical subjects

Karen L Goa

Publications and source records attributed to Karen L Goa.

60 records · Page 4Linked to original sources

Spotlight on insulin glargine in type 1 and 2 diabetes mellitus.

Insulin glargine is a recombinant human insulin analog produced by DNA technology using a nonpathogenic strain of Escherichia coli. Two modifications of human insulin result in a stable molecule which is soluble in slightly acidic conditions (pH 4.0) and precipitates in the neutral pH of subcutaneous tissue. Because of these properties, absorption of insulin glargine is delayed and the analog provides a fairly constant, basal insulin supply without peaks in plasma insulin levels for approximately 24 hours, similar to that achieved by a continuous subcutaneous insulin infusion. Insulin glargine is indicated as a once daily subcutaneous injection to provide basal glycemic control in adults and children aged >6 years with type 1 diabetes mellitus and in adults with type 2 diabetes mellitus. Fasting plasma glucose and fasting blood glucose levels generally improved to a greater extent in patients with type 1 diabetes mellitus receiving insulin glargine than patients who administered Neutral Protamine Hagedorn (NPH) insulin. In patients with type 1 or 2 disease, glycosylated hemoglobin levels were slightly reduced and to a similar extent with insulin glargine and NPH insulin. Most clinical trials in patients with type 1 or 2 diabetes mellitus demonstrated a lower incidence of hypoglycemia, especially nocturnal hypoglycemia, with insulin glargine compared with NPH insulin. One of the most common adverse events with insulin glargine treatment was injection site pain which, in some studies, occurred more frequently than in patients receiving NPH insulin. In all cases the symptoms were mild and treatment discontinuation was not required. Otherwise, the drug is well tolerated and does not appear to be immunogenic. In conclusion, insulin glargine once a day provides basal control of glycemia for approximately 24 hours without inducing peaks in plasma insulin levels in patients with type 1 or 2 diabetes mellitus. In long-term, well designed trials insulin glargine once daily improved glycemic control at least as effectively as NPH insulin given once or twice daily. The drug was well tolerated and in most studies the incidence of nocturnal hypoglycemia was significantly less in patients treated with insulin glargine compared with patients receiving NPH insulin. Therefore, insulin glargine is likely to be a useful addition to the armamentarium of insulin therapy by establishing basal glycemic control with once daily administration and a reduced risk of nocturnal hypoglycemia.

Diabetes Mellitus, Type 1↗

Spotlight on rosiglitazone in the management of type 2 diabetes mellitus.

UNLABELLED: Rosiglitazone, a thiazolidinedione with a different side chain from those of troglitazone and pioglitazone, reduces plasma glucose levels and glucose production and increases glucose clearance in patients with type 2 diabetes mellitus. Insulin sensitivity, pancreatic beta-cell function and surrogate markers of cardiovascular risk factors are significantly improved by rosiglitazone. Double-blind trials of 8 to 26 weeks of rosiglitazone 4 or 8 mg/day monotherapy indicate significant decreases in fasting plasma glucose (-2 to -3 mmol/L with 8 mg/day) and glycosylated hemoglobin levels [HbA(1c); -0.6 to -0.7% (-0.8 to -1.1% in drug-naive patients) with 8 mg/day]. Significant decreases in hyperglycemic markers occurred when rosiglitazone was combined with metformin (HbA(1c) -0.8 to -1.0%), a sulfonylurea (-1.4%) or insulin (-1.2%) for 26 weeks versus little change with active comparator monotherapy. Efficacy was maintained in trials of < or =2 years, and was also apparent in various ethnic subgroups, elderly patients and both obese and nonobese patients. Rosiglitazone is currently not indicated in combination with injected insulin. It should be administered in conjunction with diet and exercise regimens. Rosiglitazone is generally well tolerated. Despite rare individual reports of liver function abnormalities in rosiglitazone recipients, the incidence of these in clinical trials (< or =2 years' duration) was similar to that in placebo and active comparator groups. Fluid retention associated with rosiglitazone may be the cause of the increased incidence of anemia in clinical trials, and also means that patients should be monitored for signs of heart failure during therapy. Although bodyweight is increased overall with rosiglitazone therapy, increases are in subcutaneous, not visceral, fat; hepatic fat is decreased. The pharmacokinetic profile of rosiglitazone is not substantially altered by age or renal impairment, nor are there important drug interactions. Rosiglitazone is not indicated in patients with active liver disease or increased liver enzymes. CONCLUSIONS: Oral rosiglitazone 4 or 8 mg/day provides significant antihyperglycemic efficacy and is generally well tolerated, both as monotherapy and in combination with other antihyperglycemic agents, in patients with type 2 diabetes mellitus who do not have active liver disease. Long-term data are required before conclusions can be drawn about the clinical significance of positive changes to surrogate markers of cardiovascular disease risk and improvements to pancreatic beta-cell function. Rosiglitazone significantly improves insulin sensitivity and, as such, is a welcome addition to the treatment options for patients with type 2 diabetes mellitus.

Diabetes Mellitus, Type 2↗

Valsartan: in chronic heart failure.

Valsartan, an orally active nonpeptide angiotensin II (AII) receptor antagonist with selectivity for the AII type I (AT(1)) receptor subtype, has recently been approved by the US Food and Drug Administration for the treatment of patients with heart failure (New York Health Association class II-IV) who are intolerant of ACE-inhibitor therapy. Results from the Valsartan Heart Failure Trial (Val-HeFT) showed that in patients with chronic heart failure (CHF) [n = 5010], valsartan 160 mg twice daily, when used in combination with conventional therapy for heart failure, reduced the risk of the combined endpoint of mortality and morbidity by 13.2% compared with placebo. However, there was no significant difference in overall mortality between the valsartan and placebo groups. Morbidity was defined as cardiac arrest with resuscitation, hospitalization for heart failure, or administration of intravenous inotropic or vasodilator drugs for > or =4 hours without hospitalization. Among patients not receiving an ACE inhibitor, irrespective of concomitant beta-blocker use, valsartan reduced the risk of mortality and the combined endpoint by 33.1% and 44% compared with placebo; total hospitalizations for heart failure were also significantly lower in the valsartan group (27.6 vs 64.6%). In the subgroup of patients who were taking an ACE inhibitor and a beta-blocker at baseline (n = 1610), mortality was significantly higher in the valsartan group than in the placebo group. The most common adverse events in the valsartan and placebo groups which led to discontinuation of treatment were dizziness, renal impairment (both of which occurred in significantly more valsartan recipients) and hypotension.

Administration, Oral↗

Cyclosporin. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use in immunoregulatory disorders.

Cyclosporin is a lipophilic cyclic polypeptide which produces calcium-dependent, specific, reversible inhibition of transcription of interleukin-2 and several other cytokines, most notably in T helper lymphocytes. This reduces the production of a range of cytokines, inhibiting the activation and/or maturation of various cell types, including those involved in cell-mediated immunity. Thus, cyclosporin has immunosuppressive properties, and has a proven place as first line therapy in the prophylaxis and treatment of transplant rejection. Cyclosporin has also been evaluated in a large range of disorders where immunoregulatory dysfunction is a suspected or proven aetiological factor, and this is the focus of the present review. In patients with severe disease refractory to standard treatment, oral cyclosporin is an effective therapy in acute ocular Behçet's syndrome, endogenous uveitis, psoriasis, atopic dermatitis, rheumatoid arthritis, active Crohn's disease and nephrotic syndrome. Concomitant low dose corticosteroid therapy may improve response rates in some disorders. The drug can be considered as a first line therapy in patients with moderate or severe aplastic anaemia who are ineligible for bone marrow transplantation, with the additional benefit of reducing platelet alloantibody titres. It may also be of considerable therapeutic benefit in patients with primary biliary cirrhosis, particularly those with less advanced disease. Limited evidence suggests cyclosporin is effective in patients with intractable pyoderma gangrenosum, polymyositis/dermatomyositis or severe, corticosteroid-dependent asthma. Indeed, the steroid-sparing effect of cyclosporin is a significant advantage in a number of indications. Furthermore, the drug has shown some efficacy in a wide range of other, generally uncommon disorders in which controlled clinical trials are lacking and/or are unlikely to be performed. Cyclosporin does not appear to be effective in patients with allergic contact dermatitis, multiple sclerosis or amyotrophic lateral sclerosis. It is only temporarily effective in patients with type I (insulin-dependent) diabetes mellitus and should not be used in this indication. To avoid relapse after control of active disease, patients should receive cyclosporin maintenance therapy at the lowest effective dosage. However, maintenance therapy appears to be of no benefit in patients with Crohn's disease and cyclosporin should be discontinued in these patients once active disease is controlled. Hypertrichosis, gingival hyperplasia, and neurological and gastrointestinal effects are the most common adverse events in cyclosporin recipients, but are usually mild to moderate and resolve on dosage reduction. Changes in laboratory variables indicating renal dysfunction are relatively common, although serious irreversible damage is rare.(ABSTRACT TRUNCATED AT 400 WORDS)

Arthritis, Rheumatoid↗

Gabapentin. A review of its pharmacological properties and clinical potential in epilepsy.

Gabapentin is an antiepileptic drug with an unknown mechanism of action apparently dissimilar to that of other antiepileptic agents, and possessing some desirable pharmacokinetic traits. The drug is not protein bound, is not metabolised and does not induce liver enzymes, diminishing the likelihood of drug interactions with other antiepileptic agents and drugs such as oral contraceptives. Although gabapentin is a structural analogue of the neurotransmitter gamma-aminobutyric acid (GABA), which does not cross the blood-brain barrier, gabapentin penetrates into the CNS and its activity is seemingly distinct from GABA-related effects. Present clinical evaluation is largely restricted to proof of efficacy trials of gabapentin as add-on therapy in patients with partial epilepsy resistant to conventional treatment. Gabapentin (usually 600 to 1800 mg/day) provides notable benefit, reducing seizure frequency by > or = 50% in 18 to 28% of patients with refractory partial seizures, as shown in 3 double-blind, placebo-controlled trials. Overall, seizure frequency decreased by 18 to 32% during 3-month treatment periods. Patients with complex partial seizures, and partial seizures secondarily generalised, are particularly likely to respond to gabapentin. Current experience with the drug in other seizure types, and as monotherapy, is limited. Mild adverse events, commonly somnolence, fatigue, ataxia and dizziness, have been reported in about 75% of gabapentin recipients. While the drug has been well tolerated when administered to a few patients for periods of up to 5 years, its long term tolerability profile has yet to be fully expounded. Thus, with its favourable pharmacokinetic profile, and efficacy in some refractory patients, gabapentin is poised to fill a niche as an adjunct to the treatment of partial epilepsy. Promising results obtained thus far warrant further work to clarify its long term tolerability, its possible efficacy in other seizure types, its position relative to other agents and its use as monotherapy. In the meantime, gabapentin is likely to provide a much-needed option in a therapeutic area requiring complex management.

Acetates↗

Propiram. A review of its pharmacodynamic and pharmacokinetic properties, and clinical use as an analgesic.

Propiram is an orally administered opioid analgesic with partial morphine-like agonist and weak antagonist properties. Analgesic efficacy of propiram, usually 50 or 100mg, appears comparable to that of standard dosages of other oral opioid drugs [i.e. pentazocine, pethidine (meperidine)] in patients with acute pain of moderate to severe intensity arising from various gynaecological and surgical procedures, and may be superior to codeine in gynaecological and postoperative dental pain. Some evidence of a more rapid onset of action for propiram than for these opioid agents, and a longer duration of action for propiram than for codeine, is encouraging but remains to be substantiated in more extensive clinical use. The tolerability profile of propiram resembles those of others in its class, with drowsiness, nausea and vomiting, and dizziness experienced most frequently in controlled trials. The apparently low propensity of propiram for development of physical dependence and psychotomimetic effects requires confirmation with wider clinical experience. Available data thus indicate that propiram is an effective, orally administered opioid analgesic suitable for providing relief of acute moderate to severe pain arising from various surgical or gynaecological procedures, and that the drug is likely to become a useful alternative in such conditions where opioid analgesia is appropriate.

Administration, Oral↗