Triamcinolone acetonide. A review of its pharmacological properties and therapeutic efficacy in the management of allergic rhinitis.

Triamcinolone acetonide is a synthetic glucocorticoid which has been formulated as both an aerosol and an aqueous metered-dose pump spray for nasal inhalation in the treatment of allergic rhinitis. Nasally administered triamcinolone acetonide is not significantly absorbed into the systemic circulation and does not suppress hypothalamic-pituitary-adrenal (HPA) axis function at therapeutic dosages. Clinical trials with either formulation have shown that once-daily triamcinolone acetonide 110 to 220 micrograms reduces symptoms of allergic rhinitis within the first day of administration. Once symptoms are under control, the dosage of aqueous triamcinolone acetonide may be reduced from 220 to 110 micrograms/day without loss of effect. Both aqueous and aerosol formulations of triamcinolone acetonide are significantly more effective in relieving symptoms and reducing nasal eosinophil influx than placebo. Once-daily intranasal triamcinolone acetonide 220 micrograms/day produced similar reductions from baseline in nasal symptoms of allergic rhinitis, when measured both subjectively (visual analogue scales) and objectively (anterior rhinomanometry), to those seen with beclomethasone 84 to 168 micrograms twice daily, fluticasone 200 micrograms once daily or flunisolide 100 micrograms twice daily for 3 to 12 weeks. Furthermore, triamcinolone acetonide aerosol 220 micrograms/day was significantly more effective at reducing the nasal symptoms of allergic rhinitis than the oral antihistamines loratadine and astemizole (both 10mg daily) and was equally as effective in reducing the associated ocular symptoms. The use of intranasal triamcinolone acetonide and oral loratadine in combination did not confer any additional advantage over triamcinolone acetonide alone. Triamcinolone acetonide [110 to either 220 micrograms/day (aqueous) or 440 micrograms/day (aerosol)] was well tolerated in clinical trials; headache and epistaxis were the only adverse events considered possibly or probably related to aerosol therapy in a 1-year study (110 to 440 micrograms/day). Therefore, in accordance with the recommendations from the International Rhinitis Management Working Group regarding the use of nasal glucocorticoids, triamcinolone acetonide may be considered a first-line therapy option in adults with moderately severe seasonal allergic rhinitis with predominantly nasal symptoms and also in children and adult patients with perennial allergic rhinitis.

Transdermal fentanyl. A review of its pharmacological properties and therapeutic efficacy in pain control.

Fentanyl is a synthetic opioid with short-acting analgesic activity after intravenous or subcutaneous administration. The low molecular weight, high potency and lipid solubility of fentanyl make it suitable for delivery via the transdermal therapeutic system (TTS). These systems are designed to release the drug into the skin at a constant rate ranging from 25 to 100 micrograms/h, multiple systems can be applied to achieve higher delivery rates. Initially, much of the clinical experience with fentanyl TTS was obtained in patients with acute postoperative pain. However, because of the increased risk of respiratory complications, fentanyl TTS is contraindicated in this setting. Fentanyl TTS is recommended for use in chronic cancer pain. Moreover, in 11 countries worldwide including the US, its use is not restricted to chronic cancer pain; the drug is also available for treatment of general chronic pain, including that of nonmalignant origin. At the start of fentanyl TTS treatment, depot accumulation of the drug within skin tissue results in a significant delay (17 to 48 hours) before maximum plasma concentration is achieved. Approximately half of the cancer patients converted to transdermal fentanyl from other opioid agents required increased dosages after initial application of the patch. However, concomitant use of short-acting morphine maintained pain relief during the titration period, and the use of such supplementary medication decreased with the duration of fentanyl TTS treatment. In patients with chronic cancer pain, changes in visual analogue scale (VAS) pain scores ranged from a 10% increase (worse pain) to > 50% decrease (less pain) during transdermal fentanyl therapy compared with previous opioid treatment. In addition, patient preference for fentanyl TTS was indicated by the number of patient requests (up to 95%) for continued use of the drug at the end of the study. Although fentanyl TTS is contraindicated in patients postoperatively, the efficacy of fentanyl via the transdermal route was investigated in this patient group. Supplementary patient controlled analgesia was significantly reduced in patients who received fentanyl TTS 75 micrograms/h compared with placebo, although this was not apparent until > or = 12 hours after application. Data evaluating pain relief, which was assessed by VAS pain scores, were inconclusive. Preliminary data, although from relatively small numbers of patients, indicate that transdermal fentanyl may be useful in the management of chronic non-malignant pain. Indeed, some patients whose pain was previously uncontrolled became completely pain free. The most frequently occurring adverse events during fentanyl TTS therapy (as with other opioid agents) included vomiting, nausea and constipation, although vomiting and nausea were not clearly associated with the drug. The most serious adverse event was hypoventilation, which occurred more frequently in postoperative (4%) than in cancer patients (2%). In surgical patients, fentanyl-associated respiratory events (reduced respiratory rate and apnoea) generally occurred within 24 hours of patch application; however, there were isolated reports of late onset (> or = 36 hours postsurgery) fentanyl-associated respiratory depression. In cancer patients, the incidence of constipation was reduced by up to two-thirds after switching from oral morphine to transdermal fentanyl. Transient skin irritation associated with the plastic patch or the adhesive, rather than the drug, was reported in a maximum 3% of patients. In summary, transdermal fentanyl is a useful alternative to other opioid agents, which are also recommended on the third step of the WHO analgesic ladder, in the management of chronic malignant pain. Preliminary data indicate that it may be useful in the management of chronic nonmalignant pain. The advantages offered by fentanyl TTS over traditional methods of chronic pain control include its ease of administration, less constipation and the 3-

Alendronate. A review of its pharmacological properties and therapeutic efficacy in postmenopausal osteoporosis.

Alendronate is an aminobisphosphonate which appears to attenuate, rather than completely inhibiting bone turnover, by suppressing the activity of osteoclasts. Clinical trials have established that 10 mg/day orally administered alendronate is the optimum dosage. Despite its poor bioavailability after oral administration, alendronate is highly effective at preventing bone loss associated with the absence of endogenous estrogen. A sustained increase in bone mass was observed during alendronate therapy without accelerated loss after withdrawal of the drug. Increased bone mass was associated with a reduction in the risk and rate of occurrence of vertebral fractures. A recent study demonstrated a 47% reduction in the risk of developing new radiographic vertebral fractures over 3 years in women with low bone mass and pre-existing vertebral fractures. There have been few direct comparisons in clinical trials. However, when compared with calcium or low dosages of salmon calcitonin (salcatonin) therapy in women with postmenopausal osteoporosis, alendronate induced a sustained increase in bone mass during therapy that was not seen with the comparator. In clinical trials alendronate was generally well tolerated when taken as recommended. Adverse events tended to be transient and usually associated with the upper gastrointestinal tract; the most common events included abdominal pain, nausea, dyspepsia, constipation and diarrhoea, which are also common with other bisphosphonates. Of potential concern are the small number of reports of patients developing oesophageal ulceration; however, this adverse event was attributed to noncompliance with the manufacturer's recommendations for administration of the drug. In addition, alendronate has not been associated with osteomalacia. Studies are still required to establish the long term efficacy of alendronate, particularly with regard to other available therapies. Although estrogen replacement therapy is generally considered the treatment of choice for the management of postmenopausal osteoporosis, many women are unable or unwilling to receive estrogens on a long term basis. Thus, alendronate, with its demonstrated beneficial effects and its good tolerability profile (when taken as recommended), is a promising alternative treatment option for the management of postmenopausal osteoporosis.

Aldesleukin (recombinant interleukin-2): a review of its pharmacological properties, clinical efficacy and tolerability in patients with renal cell carcinoma.

Aldesleukin (recombinant interleukin-2), like endogenous interleukin-2 (IL-2), has a variety of immunomodulatory properties. It is currently approved for intravenous use in patients with renal cell carcinoma, in whom it appears to have an indirect antitumour effect mediated by increased activity of the host's immune system. A large number of clinical trials (typically noncomparative) have established the efficacy of aldesleukin monotherapy in patients with renal cell carcinoma. Response rates of 13 to 20% achieved after intravenous administration and 18 to 31% after subcutaneous administration are greater than those previously reported ( approximately 10%) for other chemo- and immunotherapeutic agents. Furthermore, many patients who were previously refractory to treatment have achieved stable disease status or better after aldesleukin therapy. Median survival times of at least 37 months have been achieved, and perhaps more encouraging is an isolated report of a 5-year actuarial survival rate of 23%. Bolus intravenous administration of aldesleukin was associated with frequent, and occasionally life-threatening, adverse events. Hypotension and renal, pulmonary and cardiac complications were primarily manifestations of increased vascular permeability. Symptoms were generally manageable with treatment interruption and standard pharmaceutical and/or clinical intervention, although some treatment-related deaths were reported. The severity of adverse events was reduced with continuous infusion of the agent and more substantially so when aldesleukin was administered subcutaneously. In conclusion, despite a lack of comparative and phase III trials, aldesleukin therapy appears to result in a slightly better response rate than those previously reported with other antineoplastic therapies in this difficult-to-treat patient population. Retrospective data indicate that survival duration may be moderately increased by aldesleukin, but further prospective comparative data are required before this may be proven. In view of the poor prognosis associated with renal cell carcinoma, efficacy data from clinical trials evaluating aldesleukin, together with the potential for reducing adverse events by changing its route of administration, suggest the drug may be a worthwhile therapy for patients with this disease.