Biomedical subjects

K L Goa

Publications and source records attributed to K L Goa.

At least 127 records · Page 7Linked to original sources

PubMed1994

Streptokinase. A review of its pharmacology and therapeutic efficacy in acute myocardial infarction in older patients.

Streptokinase has been administered to many thousands of elderly patients with acute myocardial infarction. Results of large, randomised trials provide convincing evidence that intravenous streptokinase confers a distinct survival benefit in this population subgroup following myocardial infarction. The placebo-controlled ISIS-2 study demonstrated a 5-week absolute mortality reduction of 38 per 1000 patients aged 60 to 69 years administered streptokinase, compared with only 16 per 1000 for patients aged less than 60 years. Combining streptokinase with aspirin further reduces mortality, as shown by a 5-week absolute mortality reduction of 70 per 1000 patients aged 60 to 69 years administered this regimen in the ISIS-2 trial. While ideally patients should receive streptokinase as soon as possible after symptom onset, late benefit has been observed in patients presenting up to 12 hours after pain onset, as is often the case with the elderly. Indeed, in patients treated > 6 hours after infarct in the GUSTO trial, streptokinase produced lower mortality results than accelerated recombinant tissue plasminogen activator (rt-PA). However, in contrast to the similar effects of streptokinase and conventionally administered rt-PA on overall survival demonstrated in previous large trials, the GUSTO study showed a lower mortality rate for accelerated rt-PA than for streptokinase in the elderly and in the total patient population. The most frequent adverse effects associated with streptokinase therapy are haemorrhagic complications, with an incidence of 0.4% for major bleeding (requiring transfusion) and 3.6% for minor bleeding among the total population in the GISSI-1 and ISIS-2 trials. An excess of stroke, particularly haemorrhagic stroke, occurring with rt-PA in GUSTO and other major mortality trials affirms the use of streptokinase as a suitable option in the elderly who are at increased risk of this complication. Significantly reduced values of end-systolic volume and regional wall motion index have been observed in elderly patients following streptokinase therapy. Overall, streptokinase and rt-PA seem to cause similar improvements in left ventricular function in this age group. Patency of occluded coronary arteries appears to be achieved in a high percentage of elderly patients following streptokinase therapy, based on a small sample. Thus, in view of the extensive clinical experience that now exists, intravenous streptokinase represents an appropriate alternative in elderly patients with acute myocardial infarction, and may be considered a first-line therapy in selected individuals, such as those with multiple risk factors for stroke or who present later than 6 hours after infarct.(ABSTRACT TRUNCATED AT 400 WORDS)

Aging↗

PubMed1994

Vinorelbine. A review of its pharmacological properties and clinical use in cancer chemotherapy.

Vinorelbine is a semisynthetic vinca alkaloid with a broad spectrum of antitumour activity. The drug is effective as a single agent in inoperable/advanced non-small cell lung cancer (NSCLC), producing objective response rates of about 15 to 30%, and as first-line or later chemotherapy for metastatic spread in advanced breast cancer. Combining vinorelbine with standard chemotherapeutic regimens improves response rates in these indications compared with vinorelbine monotherapy: in NSCLC response rates increase to 30 to 50% when vinorelbine is administered with cisplatin. Importantly, survival was prolonged by a further 9 weeks with this combination in a trial in > 600 patients with NSCLC. Comparative trials evaluating vinorelbine in women with advanced breast cancer are few at present. However, results suggest greater efficacy for vinorelbine than for melphalan as second-line chemotherapy, and similar efficacy for vinorelbine plus doxorubicin compared with doxorubicin plus 2 other drugs as first-line chemotherapy. Vinorelbine has tended to yield superior response rates when compared with vindesine, and appears to have greater haematological toxicity (i.e. granulocytopenia) but less neurological toxicity (peripheral neuropathy, constipation, loss of deep tendon reflexes) than this agent. Myelosuppression is the most frequent cause of vinorelbine treatment delay or dose reduction. Other consequences of vinorelbine therapy are those typically seen with antineoplastic agents, such as diarrhoea, nausea and vomiting, and alopecia. However, these are rarely severe. Early clinical investigations indicate that the antitumour effects of vinorelbine in other malignancies including ovarian carcinoma, lymphoma and head and neck cancer warrant further exploration, as does the efficacy of the drug relative to standard approaches and its possible beneficial effects on quality of life of cancer patients. Clarification is also required of the feasibility of an oral dosage form, which in preliminary investigations has shown some efficacy in NSCLC, but a variable response rate and high incidence of gastrointestinal disturbances in women with breast cancer. Thus, vinorelbine as a single agent or combined palliative therapy is effective against advanced NSCLC, and as first- or second-line chemotherapy in advanced breast cancer. This semisynthetic vinca alkaloid has a manageable tolerability profile and potential for use in other malignancies and as an oral formulation. With these attributes, vinorelbine is a valuable option which extends the range of treatments available for these difficult-to-treat malignancies.

Absorption↗

PubMed1994

Calcitriol. A review of its use in the treatment of postmenopausal osteoporosis and its potential in corticosteroid-induced osteoporosis.

A synthetic form of calcitriol (1,25-dihydroxycholecalciferol; 1,25-dihydroxyvitamin D3), the most physiologically active metabolite of vitamin D, has shown efficacy in the treatment of postmenopausal osteoporosis and promise in corticosteroid-induced osteoporosis. Although results of small studies investigating calcitriol in the treatment of postmenopausal osteoporosis have been conflicting, a clinical trial in 622 women with postmenopausal osteoporosis demonstrated that patients with mild to moderate disease who received calcitriol (0.25 microgram twice daily) had a significant 3-fold lower rate of new vertebral fractures after 3 years of treatment, compared with patients receiving elemental calcium 1000 mg/day. In patients commencing long term treatment with prednisone or prednisolone, calcitriol 0.5 to 1.0 micrograms/day plus calcium 1000 mg/day, administered with or without intranasal calcitonin 400 IU/day, prevented steroid-induced bone loss. Overall, calcitriol is well tolerated. As shown in clinical studies, at recommended dosages hypercalcaemia is infrequent and mild, generally responding to reductions in calcium intake and/or calcitriol dosage. The narrow 'therapeutic window' of calcitriol requires that its use be adequately supervised, with periodic monitoring of serum calcium and creatinine levels. However, significant renal toxicity has not been seen in patients with osteoporosis treated with calcitriol in high dosages for several years in comparative and noncomparative trials. In conclusion, as with other drugs currently used in the management of patients with osteoporosis, questions remain to be answered regarding the efficacy of calcitriol relative to other agents, and its tolerability in such patients during the very long term. Nonetheless, at this stage, calcitriol should be considered a useful treatment option in patients with mild to moderate postmenopausal osteoporosis.

Adrenal Cortex Hormones↗

PubMed1994

Aciclovir. A reappraisal of its antiviral activity, pharmacokinetic properties and therapeutic efficacy.

Aciclovir (acyclovir) is a nucleoside analogue with antiviral activity in vitro against the herpes simplex viruses (HSV), varicella zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human herpesvirus 6 (HHV-6). Topical, oral or intravenous aciclovir is well established in the treatment of ophthalmic, mucocutaneous and other HSV infections, with intravenous aciclovir the accepted treatment of choice in herpes simplex encephalitis. The efficacy of aciclovir is increased with early (preferably during the prodromal period) initiation of treatment but, despite significant clinical benefit, viral latency is not eradicated, and pretreatment frequencies of recurrence usually continue after episodic acute treatment is completed. Intravenous administration has also shown benefit in the treatment of severe complications of HSV infection in pregnancy, and neonatal HSV infections. Recurrence of HSV has been completely prevented or significantly reduced during suppressive therapy with oral aciclovir in immunocompetent patients. Use of oral aciclovir is effective but controversial in the treatment of otherwise healthy individuals with varicella (chickenpox), and in some countries it has been recommended for use only in cases which may be potentially severe. The development of rash and pain associated with herpes zoster (shingles) is attenuated with oral or intravenous aciclovir therapy, ocular involvement is prevented, and post-herpetic neuralgia appears to be decreased. Similarly, in a few patients with zoster ophthalmicus, oral aciclovir has reduced the frequency and severity of long term ocular complications and post-herpetic neuralgia, and herpes zoster oticus is improved with intravenous aciclovir. Oral aciclovir has prevented recurrence of HSV genital or orofacial infections during suppressive therapy in > 70% of immunocompetent patients in most clinical trials. Suppression of latent HSV, VZV and CMV infections has been achieved in many immunocompromised patients receiving the oral or intravenous formulations. Aciclovir also appears to offer partial protection from invasive CMV disease in CMV-seropositive bone marrow transplant recipients. The few comparative trials published have shown aciclovir to be at least as effective as other investigated antivirals in the treatment of HSV infections in immunocompetent patients, and more effective than inosine pranobex in the prophylaxis of genital herpes. Similarly, in isolated clinical trials, oral aciclovir appears as effective as topical idoxuridine and oral brivudine in some parameters in immunocompetent patients with VZV infections, and the intravenous formulation appears at least as effective as oral brivudine and intravenous vidarabine in treating these infections in immunocompromised patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Acyclovir↗

PubMed1994

Hyaluronic acid. A review of its pharmacology and use as a surgical aid in ophthalmology, and its therapeutic potential in joint disease and wound healing.

Hyaluronic acid is a naturally occurring polysaccharide with distinct physicochemical properties which underlie its application as a viscoelastic tool in ophthalmological surgery. In cataract surgery the role of hyaluronic acid in facilitating procedures and protecting the corneal endothelium is well established. Some benefit has also been gained with the use of hyaluronic acid in penetrating keratoplasty, trabeculectomy, retinal reattachment and trauma surgery, although its efficacy in these indications is less well-defined in the published literature. In addition to its lubricating and cushioning properties, demonstration of some in vitro anti-inflammatory activity and a possible disease-modifying effect for hyaluronic acid in animals has prompted its investigation as a treatment in osteoarthritis and, to a much lesser extent, in rheumatoid arthritis. Hyaluronic acid 20 mg, as weekly intra-articular injections for 3 to 7 weeks, improved knee pain and joint motion in patients with osteoarthritis. Although this occurred to a greater degree than with placebo in most comparisons, the effects of hyaluronic acid was similar to those of placebo in the largest trial. In the few available comparisons with other agents, hyaluronic acid appeared equivalent to methylprednisolone 40 mg (for 3 weeks) and to a single injection of triamcinolone 40 mg. Hyaluronic acid was distinguished from other therapies by providing a sustained effect after treatment discontinuation. Together with its very good tolerability profile, these properties justify further study of hyaluronic acid in patients with osteoarthritis. Some limited evidence of improvement in patients with rheumatoid arthritis, and a possible healing effect of hyaluronic acid on tympanic membrane perforations, represent additional areas of interest for future investigation. In summary, hyaluronic acid is a well-established adjunct to cataract surgery and may prove to be a promising option in the treatment of patients with osteoarthritis. Its very good tolerability provides further impetus for examination of its potential role in an extended scope of arthritic and ophthalmological indications, and in wound healing.

Adjuvants, Pharmaceutic↗

PubMed1994

Clodronate. A review of its pharmacological properties and therapeutic efficacy in resorptive bone disease.

Clodronate (clodronic acid, dichloromethylene bisphosphonate) is a bisphosphonate which has demonstrated efficacy in patients with a variety of diseases of enhanced bone resorption including Paget's disease, hypercalcaemia of malignancy and osteolytic bone metastases. In addition, early reports demonstrating potential efficacy of clodronate in the treatment of osteoporosis suggest a possible role in this debilitating disease. Short term intravenous administration (usually 300 mg/day for 5 days) or longer courses of oral clodronate (usually 1600 mg/day for 6 months) effectively reduced bone pain and/or improved mobility in most patients with Paget's disease, and these effects persisted for up to 12 months after discontinuing clodronate. When administered intravenously (300 mg/day for up to 12 days) to patients with malignant hypercalcaemia, serum calcium levels declined significantly within 2 days of starting treatment and approximately 70 to 95% of patients became normocalcaemic. While there is less experience with oral administration, clodronate (800 to 3200 mg/day) achieved normocalcaemia in the majority of patients, usually within 1 week, and serum calcium levels remained significantly reduced from baseline for up to 6 months with continued treatment. Clodronate is clearly superior to placebo and, based on a retrospective analysis, appears to produce greater and more sustained reductions in serum calcium levels than calcitonin in patients with malignant hypercalcaemia. The few available prospective comparative trials showed that clodronate is at least as effective as etidronate, but comparisons with alendronate and pamidronate produced results of questionable clinical relevance because of low bisphosphonate dosages used in these trials. Nevertheless, single intravenous doses of clodronate 600 mg or alendronate 7.5 mg (both agents repeated on day 3 if necessary) were comparable in efficacy, whereas a single intravenous dose of pamidronate 30 mg was more effective than a single intravenous dose of clodronate 600 mg. Normocalcaemic patients with osteolytic bone metastases due to advanced breast cancer experienced significant reductions in the number of episodes of hypercalcaemia and terminal hypercalcaemia, incidence of vertebral fractures and overall rate of morbid events, including the need for radiotherapy to treat bone-related pain, following treatment with clodronate 1600 mg/day for 3 years in a large placebo-controlled study. A similar large placebo-controlled trial in patients with multiple myeloma demonstrated that clodronate 2400 mg/day orally for 2 years significantly reduced progression of osteolytic bone lesions. Follow-up data from clinical trials revealed that the effects on development of fractures and hypercalcaemia persisted for at least 12 months after the drug was discontinued.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1994

Recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF): an appraisal of its pharmacoeconomic status in neutropenia associated with chemotherapy and autologous bone marrow transplant.

Recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF) expedites neutrophil recovery in cancer patients receiving chemotherapy with or without autologous bone marrow transplant (ABMT). The limited cost analyses available in patients undergoing ABMT support a cost reduction of about 25 to 35% with rGM-CSF therapy, relative to placebo, generated primarily by decreases of 20 to 30% in hospitalisation costs reflecting reductions in length of hospitalisation. Results of 1 trial show equivalent cost savings of 40% versus placebo with either rGM-CSF or recombinant granulocyte colony-stimulating factor (rG-CSF) in patients with chemotherapy-induced febrile neutropenia. Whether reduced infection rates seen with rGM-CSF may lessen costs of antimicrobial therapy is undetermined; however, a 16% decrease in this cost factor was reported in 1 evaluation of high dose chemotherapy with ABMT. No analyses have assessed the cost effectiveness of rGM-CSF as prophylaxis in patients receiving chemotherapy. Survival rates have increased in patients treated with rGM-CSF after bone marrow graft failure. In contrast, with the exception of one small trial, improvements in mortality or relapse rates have not occurred with rGM-CSF used prophylactically with chemotherapy, despite favourable effects on neutrophil recovery and facilitation of dose-intensified chemotherapy regimens. Similarly, survival has not increased in patients undergoing ABMT. The long term economic impact of rGM-CSF in these indications is thus unknown. Other factors predicted to produce modest cost savings include possible reductions in expenditure related to treating mucositis, and lowered transfusion requirements in some patients. Whether rGM-CSF may provide benefits in other areas that can be expressed in economic terms, such as quality of life, also remains to be established. On the whole, rGM-CSF has a good tolerability profile, obviating the need for costly monitoring procedures. Like other expensive biotechnology products, its cost effectiveness will be aided by implementation of appropriate prescribing techniques and protocols to minimise wastage. Thus, at present rGM-CSF therapy appears to offer a means of reducing hospitalisation costs, and therefore a substantial component of treatment expenditure, in patients undergoing ABMT or with chemotherapy-induced febrile neutropenia.

Anti-Bacterial Agents↗

PubMed1994

Enalapril: a review of quality-of-life and pharmacoeconomic aspects of its use in heart failure and mild to moderate hypertension.

Enalapril is an angiotensin converting enzyme (ACE) inhibitor with an established clinical profile. In patients with symptomatic heart failure, enalapril reduces overall mortality, death from progressive heart failure and hospitalisation rates. In those with asymptomatic left ventricular dysfunction, enalapril decreases the combined risk of death and development of heart failure, and the risk of death and hospitalisation. The effects of enalapril in reducing hospitalisation rates in symptomatic patients translate into net savings in healthcare costs in heart failure. Enalapril also produces modest benefits in quality-of-life (QOL) parameters in patients with symptomatic heart failure as shown in well controlled studies. Its effects appear similar to those of hydralazine plus isosorbide dinitrate. The influence of enalapril on quality of life in patients with asymptomatic disease is minimal but not deleterious. Enalapril generally either maintains or slightly improves quality of life from baseline in patients with mild to moderate hypertension. The drug appears to have a QOL profile that is more favourable than that of propranolol and similar to those of most other comparator drugs, as assessed by subjective measures of quality of life. Clarification is required of its QOL profile relative to that of captopril, in view of conflicting results in the literature. The effects of enalapril on cognitive and psychomotor function appear to resemble those of comparator agents. Thus, enalapril has modest beneficial effects on the quality of life of patients with symptomatic heart failure, while generally maintaining quality of life in patients with asymptomatic left ventricular dysfunction or mild to moderate hypertension. Enalapril is a cost-effective treatment in heart failure that would be expected to yield considerable cost savings in this therapeutic area.

Cost-Benefit Analysis↗

PubMed1993

Defibrotide. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use in vascular disorders.

Defibrotide is a deoxyribonucleic acid derivative extracted from mammalian organs, which has been developed for the treatment of a number of vascular disorders. It appears to increase fibrinolysis and may possess antithrombotic, antiatherosclerotic and anti-ischaemic actions, probably due to its ability to selectively increase prostaglandin I2 and E2 levels and to increase tissue plasminogen activator and decrease plasminogen activator inhibitor function. Defibrotide is available as an intravenous and intramuscular preparation, and also as an oral formulation for long term use. Trials performed to date have provided initial evidence that defibrotide is effective in the treatment of peripheral obliterative arterial disease and acute thrombophlebitis, while preliminary data suggest possible use in preventing fibrin deposition in the circuitry of renal haemodialysis equipment. Efficacy in preventing deep vein thrombosis after surgery has been demonstrated but defibrotide does not appear to offer any therapeutic advantage over heparin. Further clinical experience is required in other disorders, including acute myocardial infarction, Raynaud's phenomenon, renal thrombotic microangiopathy and renal transplant rejection, before adequate assessment of efficacy in these areas can be made. Defibrotide is well tolerated, as assessed in trials of up to 6 months duration, with a low global incidence of adverse events (< 1 to 9%). Mild allergic reactions and gastrointestinal disturbances have occasionally been described, and a hypotensive effect has also infrequently been observed. Thus, available data suggest that defibrotide is a well tolerated agent with little or no anticoagulant activity, which is conveniently available in both parenteral and oral formulations. Initial data indicate that the drug may be a useful alternative in the treatment of peripheral obliterative arterial disease and thrombophlebitis, while its therapeutic potential in other vascular disorders and efficacy relative to established agents remains to be fully determined.

Animals↗

PubMed1993

Mifepristone. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential.

Mifepristone is a potent oral antiprogestogen which acts at the level of the receptor, having a high affinity for the progesterone receptor. Most of the clinical trials have studied its efficacy in the termination of early pregnancy when used in conjunction with a low dosage of a prostaglandin analogue. In these studies, mifepristone 100 to 600mg administered as a single dose or over 3 or 4 days, 36 to 48 hours before a prostaglandin analogue given vaginally, intramuscularly or orally, induced complete abortion in about 95% of women. Used alone, mifepristone is an effective cervical priming agent prior to termination of first trimester pregnancy by vacuum aspiration, and facilitates termination of second trimester pregnancy by prostaglandin by reducing the interval between the start of prostaglandin treatment and termination, the cumulative prostaglandin dosage, and the adverse effects associated with these drugs. Mifepristone can also be used to induce labour in cases of intrauterine fetal death. Mifepristone has been shown to be an effective postcoital contraceptive with a likely emergency role, since its repeated use modifies the menstrual cycle. Pilot studies have been performed in unresectable meningioma and metastatic breast cancer, and in Cushing's syndrome. Mifepristone is generally well tolerated, and thus is an effective, appropriate, medical alternative to surgical termination of early pregnancy. It has as yet unexplored potential as a postcoital contraceptive and in oncology.

Contraceptives, Postcoital↗

PubMed1993

Lamotrigine. A review of its pharmacological properties and clinical efficacy in epilepsy.

Lamotrigine is an antiepileptic drug which is believed to suppress seizures by inhibiting the release of excitatory neurotransmitters. Efficacy has been demonstrated for lamotrigine as add-on therapy to existing regimens in patients with resistant partial seizures. Total seizure frequency was reduced by 17 to 59% compared with placebo, and 13 to 67% of patients experienced reductions of > or = 50% in seizure frequency. Secondarily generalised tonic-clonic seizures respond well to lamotrigine, and there is preliminary evidence of improvement in patients with primary generalised seizures, Lennox-Gastaut syndrome and in children with multiple seizure types. Seizure control has been maintained in patients who have continued to receive lamotrigine as monotherapy after discontinuation of other medications. Results of one trial suggest similar efficacy for lamotrigine monotherapy as for carbamazepine, but confirmation of its use in this setting awaits more extensive controlled comparisons with established agents. Adverse events associated with lamotrigine as add-on therapy are typical of antiepileptic drugs, namely dizziness, ataxia and other CNS-related symptoms. Rash, which has occurred in 10% of patients in placebo-controlled trials, may be severe and its appearance has led to discontinuation of therapy in 1% of patients. Lamotrigine appears well tolerated in the longer term, but this facet of its profile requires further monitoring. Influences of valproic acid and enzyme-inducing anti-epileptics on lamotrigine eliminate necessitate dosage modification of lamotrigine. Conversely, lamotrigine has little apparent influence on the pharmacokinetics of other agents, although it may increase plasma concentrations of the active metabolite of carbamazepine during concomitant administration. Thus, lamotrigine permits improved seizure control in some patients with refractory partial seizures, and may prove to be especially effective in secondarily generalised tonic-clonic seizures. As is usual at this stage in a drug's development, several aspects of the profile of lamotrigine are incompletely defined, notably its efficacy in other seizure types, in children, as monotherapy, and its longer term tolerability. Nonetheless, lamotrigine presently offers a worthwhile alternative for the physician confronted with the challenge of treating patients with intractable partial seizures with or without secondarily generalised seizures, and shows potential for broader applications in other areas of epilepsy management.

Animals↗

PubMed1993

Idarubicin: a pharmacoeconomic evaluation of its use in adult patients with acute myeloid leukaemia.

Idarubicin is an effective agent in the treatment of acute myeloid leukaemia (AML), inducing complete remission in 39 to 80% of newly diagnosed patients. Although it also demonstrates efficacy as monotherapy, and is of use in relapsed or refractory disease, most comparative clinical trials have administered idarubicin intravenously in combination with cytarabine in newly diagnosed patients. These trials indicate that improved survival and response rates, and rapid achievement of remission, are more likely with idarubicin than with daunorubicin, when both agents are given in combination with cytarabine. In elderly patients, however, response rates are lower than in younger patients, and there is less disparity in efficacy between idarubicin and daunorubicin induction therapy. Although AML is an expensive disease to treat, the majority of costs are associated with the length of hospitalisation, with the acquisition cost of the chemotherapy agents contributing less than 10% to overall expenditure. Idarubicin combined with cytarabine therapy achieved higher response rates with the first cycle of therapy than daunorubicin, thereby reducing the requirements for a second cycle of therapy and further hospitalisation. Compared with daunorubicin plus cytarabine induction treatment, idarubicin plus cytarabine reduced the costs of achieving a complete response by between 22 and 39% in patients with a median age less than 60 years. In patients with a median age of 62 years, who are more representative of the AML population, costs of achieving a complete response were reduced by 3 to 6%. Thus, idarubicin is more cost effective than daunorubicin as induction therapy in combination with cytarabine, in adult patients with AML. The pharmacoeconomic position of idarubicin in postinduction therapy remains to be established.

Adult↗

PubMed1992

Interferon gamma-1b. A review of its pharmacology and therapeutic potential in chronic granulomatous disease.

Chronic granulomatous disease is a group of rare x-linked or autosomal genetic disorders of the phagocytic NADPH oxidase system involved in host defence against various microorganisms. It is manifested by a common phenotype consisting of recurrent serious, life-threatening infection and granuloma formation. Following the finding that interferon gamma-1b (IFN gamma-1b) can potentiate phagocyte activity in some other disease states as well as restoring defective phagocyte NADPH oxidase system activity in at least some patients with chronic granulomatous disease, a large-scale placebo-controlled trial was undertaken with IFN gamma-1b in patients with chronic granulomatous disease. Long term treatment with a therapeutic dosage of IFN gamma-1b produced a significant reduction in the incidence of serious clinical events necessitating hospitalisation. The relative risk of serious infection and the number of days in hospital were each reduced by about two-thirds, and the mean duration of hospital stay by about one-third in those who did experience infection. The greatest therapeutic benefit was found in patients aged less than 10 years, but all patients were improved regardless of age, sex, use of prophylactic antibiotics or genetic pattern of inheritance. The drug was well tolerated with the commonest adverse effects (e.g. fever, headache, chills, injection site erythema) usually being mild, transient, and relieved by symptomatic treatment. IFN gamma-1b therefore provides an effective and well tolerated therapy for patients with chronic granulomatous disease, offering an important clinical advance in the treatment of this rare genetic disorder by improving the prognosis of its serious and life-threatening infectious sequelae.

Drug Interactions↗

PubMed1992

Halofantrine. A review of its antimalarial activity, pharmacokinetic properties and therapeutic potential.

Halofantrine is an orally administered blood schizontocide which is active against both chloroquine-sensitive and chloroquine-resistant plasmodia. Dose-finding and noncomparative clinical trials have confirmed the efficacy of halofantrine in the treatment of falciparum malaria in areas of chloroquine- and sulfonamide/pyrimethamine-resistant malaria and vivax malaria. However, poor results obtained in patients who failed mefloquine prophylaxis suggest that the efficacy of halofantrine may not extend to mefloquine-resistant P. falciparum, although more studies are needed to confirm this. Data concerning halofantrine in the treatment of P. ovale and P. malariae infections are still limited. One comparative study indicates that halofantrine has an efficacy equivalent to that of mefloquine and may be better tolerated. Halofantrine is generally well tolerated in both adults and children, the most common drug-associated effects being abdominal pain, pruritus, vomiting, diarrhoea, headache and rash, although it is difficult to distinguish between disease- and treatment-related events. The development of parasite resistance to halofantrine, like other blood schizontocides, is inevitable. Poor absorption resulting in variable peak plasma halofantrine concentrations, and possible cross-resistance with mefloquine, may accelerate the emergence of resistance to halofantrine. Thus, it is of primary importance that halofantrine is used only in areas where chloroquine- and sulfonamide/pyrimethamine-resistance are established in order to preserve and sustain its efficacy. If used with care, halofantrine will provide an important treatment option for falciparum malaria, a widespread parasitic disease associated with considerable morbidity against which the number of effective drugs available is being increasingly compromised by the spread of resistance.

Animals↗

PubMed1992

Enalapril. A reappraisal of its pharmacology and therapeutic use in hypertension.

Enalapril, an angiotensin converting enzyme (ACE) inhibitor usually administered orally once daily, decreases blood pressure by lowering peripheral vascular resistance without increasing heart rate or output. It is effective in lowering blood pressure in all grades of essential and renovascular hypertension. Patients not responding adequately to enalapril monotherapy usually respond with the addition of a thiazide diuretic (or a calcium antagonist or beta-blocker), and rarely require a third antihypertensive agent. Enalapril is at least as effective as other established and newer ACE inhibitors, and members of other antihypertensive drug classes including diuretics, beta-blockers, calcium antagonists and alpha-blockers, but therapy with enalapril may be less frequently limited by serious adverse effects or treatment contraindications than with other drug classes. The most frequent adverse effect limiting all ACE inhibitor therapy in clinical practice is cough. This favourable profile of efficacy and tolerability, and the substantial weight of clinical experience, explain the increasing acceptance of enalapril as a major antihypertensive treatment and supports its use as logical first-line therapeutic option.

Animals↗

PubMed1992

Moclobemide. A review of its pharmacological properties and therapeutic use in depressive illness.

Moclobemide is a reversible and selective inhibitor of the enzyme monoamine oxidase (MAO) subtype A with a broad spectrum of antidepressant activity. Controlled clinical studies suggest that the short term clinical efficacy of moclobemide is significantly superior to that of placebo, and comparable to that of the tricyclic antidepressants clomipramine, amitriptyline, imipramine and desipramine, the irreversible MAO inhibitor tranylcypromine and the second-generation antidepressants maprotiline, mianserin and fluvoxamine in the treatment of major depressive illness. Moclobemide appears to be equally effective in endogenous and nonendogenous depression, producing marked amelioration of clinical features of psychomotor retardation and depressed mood. Moclobemide is well tolerated, being largely devoid of the anticholinergic adverse effects, symptomatic postural hypotension and weight gain variously associated with the tricyclic antidepressants and irreversible MAO inhibitors, and appears considerably safer on overdosage than the tricyclic and second generation antidepressants. Moreover, moclobemide offers the advantage over the older, irreversible MAO inhibitors of causing only minimal potentiation of the pressor response to dietary tyramine (the so-called 'cheese effect'). Consequently, the risk of potentially fatal hypertensive crisis, a major deterrent to the wider acceptance of these earlier compounds, is substantially reduced with moclobemide, and the need for dietary precautions is minimised. With its efficacy against endogenous and nonendogenous depression, relatively rapid onset of antidepressant activity, and absence of carry-over effects on treatment withdrawal, moclobemide is likely to make an important contribution to the treatment of major depressive illness. Its favourable tolerability profile, safety on overdosage and beneficial effect on age-related cognitive impairment may be of particular value in the elderly and those with concurrent physical illness.

Animals↗

PubMed1992

Iloprost. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in peripheral vascular disease, myocardial ischaemia and extracorporeal circulation procedures.

Iloprost is an analogue of epoprostenol (prostacyclin; PGI2; a potent but short-lived prostanoid mainly produced in the vascular endothelium) and mimics the pharmacodynamic properties of this compound, namely: inhibition of platelet aggregation, vasodilatation and, as yet ill-defined, cytoprotection. Improved metabolic and, in particular, chemical stability enhance the clinical utility of iloprost. When administered as an intermittent intravenous infusion at less than or equal to 2 ng/kg/min for 2 to 4 weeks, iloprost reduced rest pain and improved ulcer healing in 40 to 60% of patients with critical leg ischaemia, including diabetic patients, and delayed amputation in the majority of responding individuals. Similar benefits have been seen in thromboangiitis obliterans and, in patients with severe Raynaud's phenomenon, shorter courses of therapy reduced the frequency, intensity and duration of ischaemic episodes for at least 6 weeks. The very few comparative trials reported to date (i.e. vs nifedipine in Raynaud's phenomenon; vs low-dose aspirin in thromboangiitis obliterans) have favoured iloprost, but comparisons with more established agents are needed to assess this drug's value in less severe forms of peripheral ischaemia, such as intermittent claudication. At present, iloprost is administered intravenously and this is a limitation to treatment. The potent, rapidly reversible antiplatelet activity of iloprost suits it for use in extracorporeal circulation and for the intraoperative management of heparin-induced platelet activation. Although results in animal models of ischaemic myocardial injury are encouraging, preliminary clinical experience in patients with myocardial ischaemia or infarction has been disappointing. Most patients tolerate iloprost infusion rates of up to 2 ng/kg/min. Headache and flushing are extremely common and are the suggested end-point of dose titration, as higher doses are associated with a significant incidence of gastrointestinal distress and, ultimately, hypotension. Thus, iloprost provides a pharmacotherapeutic option for patients with severe peripheral vascular disease, a condition for which few alternative drug therapies exist. Its potent but short-lived effects make it well-suited to certain therapeutic niches such as the management of intraoperative platelet activation. Prostanoid analogues have far-reaching therapeutic potential and further experience with iloprost will no doubt help to define its clinical applications.

Coronary Disease↗

PubMed1992

Alglucerase. A review of its therapeutic use in Gaucher's disease.

Alglucerase is a mannose-terminated form of human placental glucocerebrosidase, developed to treat patients with Gaucher's disease. Functional glucocerebrosidase is deficient in Gaucher's disease, an autosomal recessive lipid storage disorder that affects people of all ethnic backgrounds, but has a higher incidence among East European Jews (Ashkenazim). Gaucher's disease manifests with hepatosplenomegaly, bleeding disorders and bone disease, with the more rare subtypes (types 2 and 3) featuring neurological dysfunction. Prior to the development of enzyme replacement therapy, treatment for Gaucher's disease was mainly symptomatic relief. Primary treatment with glucocerebrosidase focuses on removal of the lipid metabolite that causes the pathology. Because of the rarity of Gaucher's disease clinical trials are small, and much of the data investigating alglucerase therapy have been obtained from studies of patients with type 1 disease, the prevalent subtype. Nonetheless, after intravenous administration of alglucerase, improvements are evident within 6 months of therapy. Patients have increased haemoglobin levels and platelet counts, and decreased incidences of epistaxis and bruising. Spleen and liver size are reduced, and skeletal parameters improve. Children gain height and most patients receiving alglucerase therapy are able to resume work and daily activities. Alglucerase is well tolerated, with few mild adverse reactions reported. Although the pharmacokinetic and pharmacodynamic information for alglucerase is limited, its unequivocal efficacy justifies enzyme replacement therapy with this compound as first-line treatment for patients with Gaucher's disease, for whom treatment options are limited.

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