The effect of oral and inhaled beclomethasone dipropionate on adrenal function

Designing inhaled small molecule drugs for severe respiratory diseases: an overview of the challenges and opportunities

INTRODUCTION

Inhaled drugs offer advantages for the treatment of respiratory diseases over oral drugs by delivering the drug directly to the lung, thus improving the therapeutic index. There is an unmet medical need for novel therapies for lung diseases, exacerbated by a multitude of challenges for the design of inhaled small molecule drugs.

AREAS COVERED

The authors review the challenges and opportunities for the design of inhaled drugs for respiratory diseases with a focus on new target discovery, medicinal chemistry, and pharmacokinetic, pharmacodynamic, and toxicological evaluation of drug candidates.

EXPERT OPINION

Inhaled drug discovery is facing multiple unique challenges. Novel biological targets are scarce, as is the guidance for medicinal chemistry teams to design compounds with inhalation-compatible features. It is exceedingly difficult to establish a PK/PD relationship given the complexity of pulmonary PK and the impact of physical properties of the drug substance on PK. PK, PD and toxicology studies are technically challenging and require large amounts of drug substance. Despite the current challenges, the authors foresee that the design of inhaled drugs will be facilitated in the future by our increasing understanding of pathobiology, emerging medicinal chemistry guidelines, advances in drug formulation, PBPK models, and in vitro toxicology assays.

Platelet-derived growth factor D expression in adrenal cells is modulated by corticosteroids: putative role in adrenal suppression

BACKGROUND

Adrenal suppression is a clinically concerning side effect of inhaled corticosteroid (ICS) treatment in patients with asthma. Increased susceptibility to ICS-induced adrenal suppression has previously been identified in those with the rs591118 polymorphism in platelet-derived growth factor D (PDGFD). The mechanism underpinning this relationship is not known.

METHODS

H295R cells were genotyped for rs591118 using a validated Taqman PCR allelic discrimination assay. H295R cell viability was determined after treatment with beclometasone and fluticasone (range 0-330 μM). Cortisol was measured in cell culture medium using competitive enzyme immunoassay.

RESULTS

PDGFD protein expression in H295R cells was confirmed using Western blotting. When ACTH and forskolin were added to H295R cells, a reduction in PDGFD expression was seen, which was then restored by incubation with prochloraz, a known inhibitor of steroidogenesis. A dose-dependent, decrease in PDGFD expression was observed with beclometasone (over a 24 h incubation period) but not with beclometasone incubations beyond 24 h nor with fluticasone (at 24 or 48 h).

CONCLUSIONS

H295R cells express PDGFD protein, which can be modulated by incubation with steroidogenesis agonists and antagonists and additionally with exogenous beclometasone.

IMPACT

PDGFD is expressed in the human adrenal cell line, H295R, and expression can be modulated by beclometasone as well as agonists/antagonists of steroidogenesis. This builds on previous research that identified a SNP in PDGFD (rs591118) as an independent risk factor for adrenal suppression in adults and children with obstructive airway disease treated with inhaled corticosteroids. First in vitro experiments to support a link between the PDGF and cortisol production pathways, supporting the hypothesis that PDGFD variants can affect an individual's sensitivity to corticosteroid-induced adrenal suppression.

Inhaled RNA Therapeutics for Obstructive Airway Diseases: Recent Advances and Future Prospects

Obstructive airway diseases, e.g., chronic obstructive pulmonary disease (COPD) and asthma, represent leading causes of morbidity and mortality worldwide. However, the efficacy of currently available inhaled therapeutics is not sufficient for arresting disease progression and decreasing mortality, hence providing an urgent need for development of novel therapeutics. Local delivery to the airways via inhalation is promising for novel drugs, because it allows for delivery directly to the target site of action and minimizes systemic drug exposure. In addition, novel drug modalities like RNA therapeutics provide entirely new opportunities for highly specific treatment of airway diseases. Here, we review state of the art of conventional inhaled drugs used for the treatment of COPD and asthma with focus on quality attributes of inhaled medicines, and we outline the therapeutic potential and safety of novel drugs. Subsequently, we present recent advances in manufacturing of thermostable solid dosage forms for pulmonary administration, important quality attributes of inhalable dry powder formulations, and obstacles for the translation of inhalable solid dosage forms to the clinic. Delivery challenges for inhaled RNA therapeutics and delivery technologies used to overcome them are also discussed. Finally, we present future prospects of novel inhaled RNA-based therapeutics for treatment of obstructive airways diseases, and highlight major knowledge gaps, which require further investigation to advance RNA-based medicine towards the bedside.

Current approaches to the discovery of novel inhaled medicines

Inhaled administration is underutilised because the drug discovery process is viewed as challenging, risky, and expensive. However, unmet medical need continues to grow, and significant opportunities exist to discover novel inhaled medicines delivering the required lung concentrations while minimising systemic exposure. This profile could be achieved by a combination of properties, including lung retention and low oral bioavailability. Property-based rules exist for orally administered compounds, but there has been limited progress defining in silico predictors to guide the discovery of novel inhaled drugs. Recently, the use of informative cell- and tissue-based screens has greatly facilitated the identification of compounds with optimal characteristics for inhaled delivery. Here, we address opportunities for novel inhaled drugs, and the key challenges and uncertainties hampering progress.

A randomized, placebo-controlled trial of oral beclomethasone dipropionate as a prednisone-sparing therapy for gastrointestinal graft-versus-host disease

We tested the hypothesis that oral beclomethasone dipropionate (BDP) would control gastrointestinal graft-versus-host disease (GVHD) in patients with anorexia, vomiting, and diarrhea. Patients were randomized to prednisone for 10 days and either oral BDP 8 mg/d (n = 62) or placebo (n = 67) tablets for 50 days. At study day 10, prednisone was rapidly tapered while continuing study drug. On an intent-to-treat basis, the risk of GVHD-treatment failure was reduced for the BDP group at study day 50 (hazard ratio [HR] 0.63, 95% confidence interval [CI] 0.35-1.13) and at 30 days follow-up (HR 0.55, 95% CI 0.32-0.93). Among patients eligible for prednisone taper at study day 10, the risk of GVHD-treatment failure was significantly reduced at both study days 50 and 80 (HR 0.39 and 0.38, respectively). By day 200 after transplantation, 5 patients randomized to BDP had died compared with 16 deaths on placebo, a 67% reduction in the hazard of mortality (HR 0.33, P = .03). In 47 recipients of unrelated and HLA-mismatched stem cells, mortality at transplantation day 200 was reduced by 91% in the BDP group compared with placebo (HR 0.09, P = .02). The survival benefit was durable to 1 year after randomization. Oral BDP prevents relapses of gastrointestinal GVHD following tapering of prednisone; survival is statistically significantly better among patients receiving BDP.

Effect of a volumatic spacer and mouth rinsing on systemic absorption of inhaled corticosteroids from a metered dose inhaler and dry powder inhaler

BACKGROUND

High doses of inhaled corticosteroids are absorbed systemically and may cause long term side effects. As rinsing the mouth out after use and inhaling through a spacing device may reduce systemic absorption this has been further investigated.

METHODS

Three crossover studies were carried out to assess the effect of budesonide given by dry powder inhaler (Turbuhaler) with and without mouth rinsing and beclomethasone dipropionate given by metered dose inhaler with or without a spacing device (Volumatic) on serum cortisol concentrations and urinary cortisol excretion in patients with asthma taking an inhaled corticosteroid. Each treatment period was two weeks with in a two week washout period. Serum cortisol concentrations at 0800 hours on day 14 and the 24 hour urinary excretion of cortisol were measured. In study 1 24 patients taking beclomethasone dipropionate 500 micrograms twice a day inhaled with (n = 10) or without (n = 14) a Volumatic spacing device were switched to a budesonide dry powder inhaler, 600 micrograms to be taken twice a day without mouth rinsing. In study 2 10 patients took budesonide 800 micrograms twice a day with and without mouth rinsing and without swallowing the rinsing water. In study 3 17 patients took budesonide 800 micrograms twice daily with mouth rinsing and beclomethasone dipropionate 500 micrograms twice daily with the spacing device and mouth rinsing.

RESULTS

In study 1 no difference was seen between budesonide without mouth rinsing and beclomethasone dipropionate without a spacer: beclomethasone with spacer caused less suppression of cortisol (mean (SD) serum cortisol concentration: beclomethasone and spacer 487(148), budesonide 368(145) nmol/l). In study 2 mouth rinsing caused less suppression of morning serum cortisol concentrations (rinsing 440(63), no rinsing 375(56) nmol/1). In study 3 there was no difference in serum or urinary cortisol concentrations between twice daily beclomethasone dipropionate 500 micrograms inhaled by Volumatic spacer or budesonide by Turbuhaler 800 micrograms twice daily, both with mouth rinsing. Individual serum cortisol values were within the normal range in all patients except one in study 1.

CONCLUSION

Systemic absorption of a corticosteroid inhaled from a metered dose inhaler is reduced by using a spacing device and that from a dry powder inhaler by mouth rinsing.

The effects of steroids on the human lens epithelium

A study of anterior capsules from cataractous lenses revealed that there are marked abnormalities in epithelial structure associated with cataract. In certain cases a distinctive reticulated pattern was observed in whole mounts of the anterior capsule and of these a higher number than expected were from patients receiving steroid medication. In tissue culture experiments it was found that the presence of steroids in the growth medium (10 microM prednisolone) adversely affected the growth of human lens epithelial cells. These observations are consistent with the hypothesis that steroid-induced cataracts are the result of effects on anterior lens epithelial cell function.

The use of anti-asthmatic drugs. Do they affect sports performance?

Recent major advances in pharmacological management have provided asthmatics with a satisfactory range of drugs to control asthma. These include sodium cromoglycate (cromolyn sodium), H1-antagonists, belladonna alkaloids, methyl xanthines, glucocorticoids and beta 2-adrenoceptor stimulants. Despite the tendency for most asthmatics to develop bronchoconstriction after exercise, sport and physical activity are now accepted as valuable in the overall management of patients with asthma. Thus, control of exercise-induced asthma (EIA) is essential, if asthmatics are to participate safely in physical activity and without respiratory disadvantage in competitive sport. Fortunately, inhibition or minimization of exercise-induced asthma may be achieved in most asthmatics by pre-exercise aerosol beta 2-agonists supplemented if necessary by sodium cromoglycate and/or theophylline. Regular medication as required to attain and maintain normal ventilatory function throughout each day is the objective in all patients with asthma and appears to be a prerequisiste to control exercise-induced asthma. The introduction of anti-doping controls into high performance sport has presented added difficulties for the asthmatic athlete. Although not always so, currently all of the classes of drugs previously noted are acceptable for the treatment of asthma and exercise-induced asthma. Anomalies may exist in the banning of 2 beta 2-adrenoceptor agonists, fenoterol and orciprenaline (metaproterenol). All sympathomimetic amines with alpha- or predominantly beta-stimulation are banned. The perpetuation of the need to report the use of beta 2-agonists prior to competition appears unnecessary. Although relatively little specific research has been undertaken, there is minimal evidence to suggest that asthmatics can derive any additional ergogenic advantage from medication to control asthma and exercise-induced asthma. beta 2-agonists, sodium cromoglycate and glucocorticoids administered by the aerosol route are not considered to be ergogenic. Some doubts have been raised concerning theophylline and its enhancement of both cardiac and respiratory muscle function. Investigations as to the validity of the suggestion that theophylline could augment physical performance appear warranted. It is reported that some athletes may be unnecessarily taking oral and perhaps parenteral glucocorticoids to obtain certain side effects. Any decision to ban these agents except for aerosol or local use could be supported.

Combined oral and nasal beclomethasone diproprionate in children with atopic eczema: a randomised controlled trial

In a double blind, placebo controlled, crossover trial in 26 children with severe atopic eczema those receiving four weeks' treatment with combined oral plus nasal beclomethasone diproprionate improved significantly more than those receiving placebo. No adverse effects were observed, but 24 hour urinary cortisol excretion was slightly reduced. This combination may provide effective treatment in refractory atopic eczema with relatively little of the danger associated with systemic administration of prednisolone and other traditional corticosteroids.

Effects of long term inhaled high dose beclomethasone dipropionate on adrenal function

Studies of adrenal function were performed on 54 asthmatic patients who were taking long term high doses of inhaled beclomethasone dipropionate ranging from 500 to 2000 micrograms/day for between six and 60 months. Of the 43 patients taking up to 1500 micrograms/day, 39 (91%) had normal basal plasma cortisol concentrations and normal short tetracosactrin responses and 24 hour urinary free cortisol excretion was within the normal range in eight of nine patients tested. Some evidence of adrenal suppression was found in patients taking 2000 micrograms/day, with basal plasma cortisol below the normal range in four out of 11 patients and 24 hour urinary free cortisol excretion below the normal range in five out of six patients tested. Only one of the 11 patients taking 2000 micrograms/day had a short tetracosactrin response below the normal range: the mean rise in plasma cortisol was, however, significantly lower in this group than in those taking 1000 micrograms/day (328 (SE 30) and 506 (34) nmol/l respectively) (p less than 0.01). Patients taking more than 1500 micrograms/day of inhaled beclomethasone may require systemic corticosteroids during prolonged stress.

Beclomethasone dipropionate enemas for treating inflammatory bowel disease without producing Cushing's syndrome or hypothalamic pituitary adrenal suppression

Since beclomethasone dipropionate (BDP) is a very potent glucocorticoid and since small oral doses (1 mg) seem to be metabolised (possibly in the gut wall or liver) before they reach the systemic circulation, a study was conducted to find out whether patients with inflammatory bowel disease could be treated with enemas containing small doses of BDP without their acquiring Cushing's syndrome or hypothalamic pituitary adrenal (HPA) suppression. The BDP in the 100 ml enemas used was stable and present in a concentration likely to be therapeutic (0.5 mg/dl). Single overnight BDP enemas, unlike conventional betamethasone (5 mg) enemas, did not interfere with the HPA axis in 6 healthy volunteers. In the double-blind randomised part of the study 2-week courses of BDP or betamethasone enemas were assessed in 9 patients having exacerbations of distal inflammatory bowel disease. The clinical and sigmoidoscopic responses as well as adrenocortical function (judged by the 'Cosyntropin' test) were evaluated on the morning after the last day of a course of enemas. Both types of enemas had similar beneficial effects, but only BDP enemas did not interfere with HPA function. Over a prolonged period, a patient with distal ulcerative colitis had been completely dependent on regular treatment with betamethasone enemas to control his symptoms. Substitution with BDP enemas successfully controlled his bowel symptoms, whilst his cushingoid features and HPA suppression regressed.

A one-year trial of triamcinolone acetonide aerosol in severe steroid-dependent asthma

Twenty-three steroid-dependent severely asthmatic patients, ranging in age from 20 to 67 years, tolerated reduction in their oral dosage of steroids during a one-year trial of triamcinolone acetonide aerosol. Sixteen patients maintained their initial one-second forced expiratory volume without oral therapy with steroids, two required resumption of daily steroid dosage because of lethargy and arthralgia, and four required 2.5 to 20 mg of prednisone every other day to control their asthma. Five-day oral courses of steroids were occasionally required because of episodes of asthma from a variety of external causes. One patient failed to benefit within two months and withdrew from the study. One patient had precipitins to Candida albicans prior to the study, and he developed transient oropharyngeal culture-positive thrush, which subsided with use of a gargle containing nystatin. None of the other patients had oral candidiasis, and laryngoscopic examination revealed no lesions attributed to the aerosol. The mean fasting cortisol level did not increase throughout the one-year trial. Thus, the use of triamcinolone acetonide aerosol (2,000 microgram or less daily) can eliminate or greatly reduce oral requirements for steroids in patients with severe steroid-dependent asthma. Side effects are mild, but adrenal recovery may be exceedingly slow.

The endocrinometabolic effects of beclomethasone dipropionate in asthmatic patients

The endocrinometabolic effects of the aerosol administration of beclomethasone dipropionate (100 microng four times daily) were evaluated in 20 asthmatic patients (11 corticodependent and nine noncorticodependent) during one month. In the noncorticodependent group, aerosol administration of beclomethasone had no statistically significant effect on the results of the glucose tolerance test and the plasma levels of insulin; there was a slight decrease in basal levels of cortisol, but the response of the cortisol level to administration of ACTH remained quite normal. In corticodependent patients, after substitution of aerosol therapy with beclomethasone for the oral therapy with steroids, the depression of adrenal function disappeared, usually quickly (in less than one month), whereas the abnormalities in the results of the glucose tolerance test persisted. Thus, at the dosage used, beclomethasone dipropionate might have minor systemic endocrinometabolic effects.

Beclomethasone dipropionate aerosol in long-term treatment of perennial and seasonal asthma in children and adults: a report of five-and-half years' experience in 600 asthmatic patients

1 Clinical experience in the long-term treatment of allergic asthma with beclomethasone dipropionate aerosol (BDA) during the past five-and-half years is reviewed. A total of 600 patients from National Health Service and private practice, including 176 children, was treated.

2 A total of 241 patients, including 57 children, was corticosteroid-dependent for 1-18 yr. Of these patients, 70% were successfully transferred to BDA, 21% could be only partially transferred, and 9% could not. Over the years, 12% had to revert to oral corticosteroids, but 4% were able to stop BDA without relapse. Oropharyngeal thrush was observed in 16%, but in only two cases did treatment have to be withdrawn on that account. There were no deaths from asthma, and seven normal births.

3 A total of 359 non-corticosteroid-dependent asthmatics, including 119 children, were also treated with BDA. Successful control of symptoms was achieved in 99%, but 4% eventually became corticosteroid-dependent. There were three deaths from asthma and 13 normal births. Fifteen per cent were able to stop treatment without relapse. Five per cent developed oropharyngeal candidiasis, but treatment did not have to be stopped on that account.

4 In 35% of both groups, a preliminary course of oral corticosteroid at high dosage was required before the introduction of BDA therapy. Sixty-two patients were treated for over 5 yr, and approximately 1350 patient-years of BDA have been given without evidence of side-effects.

5 Thirty-one corticosteroid-dependent and 73 non-corticosteroid dependent patients with perennial asthma had 231 seasonal episodes, effectively controlled in 68%, and 38 purely seasonal asthmatics had 100 episodes, with good control in 80% of cases.

Long-term results with beclomethasone dipropionate aerosol in children with bronchial asthma: why does it sometimes fail?

1. Beclomethasone dipropionate aerosol has been shown to be a highly effective treatment for asthma in childhood, with virtual absence of side effects at this age. 2. When treatment is unsuccessful, this is usually due to failure to take it correctly and regularly. 3. A good response is usually associated with an improvement in ventilatory function and a marked increase in growth velocity.

Beclomethasone dipropionate in long-term treatment of asthma in children

Beclomethasone dipropionate was found to be effective in reducing symptoms of asthma in children. There was no measurable influence on pulmonary function. An 18-month follow-up did not show untoward side effects on adrenal function, growth, serum electrolytes, and hepatic and renal functions with a dose of 100 mug three times daily. The treatment predisposes to the colonization with Candida albicans in the oropharynx.

Beclomethasone dipropionate aerosol in the treatment of steroid-dependent asthma. A 12-week double-blind study comparing beclomethasone dipropionate and a vehicle aerosol

In a randomized double-blind 12-week trial of steroid-dependent patients with chronic asthma, ten (59 percent) out of 17 patients receiving beclomethasone dipropionate aerosol in a total daily dose of 400mug were able to discontinue systemic corticosteroid therapy successfully, compared to two (13 percent) out of 15 patients in the placebo group (P=0.002). At the end of the trial, the average 8 am plasma cortisol level in the group receiving beclomethasone was more than twice the pretherapy value, whereas the level in the placebo group showed no significant change. There was no significant difference between the beclomethasone group and the placebo group in the overall incidence of side effects related to the aerosol and the effects of systemic corticosteroid withdrawal. Oral candidiasis was not found in any patient receiving beclomethasone dipropionate aerosol. Allergic nasal symptoms were disabling in many patients when the oral dosage of corticosteroids was tapered.

A 12-month double-blind assessment of betamethasone valerate aerosol in the management of asthma

A double-blind trial of the topically active corticosteroid, betamethasone valerate in aerosol form, in the control of chronic asthma is reported. The results show that this is an extremely effective therapeutic agent in non-steroid dependent but nonetheless moderately severe asthmatics. Patients were well controlled on 800 mug of betamethasone valerate daily and control was maintained over a 12-month period. This form of treatment has few undersirable side effects but there is probably an increased incidence of oropharyngeal and laryngeal candidiasis. In particular, adrenocortical suppression was not noted.

A short-term double-blind trial of aerosol triamcinolone acetonide in steroid-dependent patients with severe asthma

Twenty-five steroid-dependent severely asthmatic patients, ranging in age from 20 to 67 years, were hospitalized. Baseline laboratory and pulmonary function testing was followed by reduction of prednisone therapy to 5 mg daily and by entry into a randomized double-blind study of placebo vs active aerosol triamcinolone acetonide (300mug four times daily). In this four-week trial, aerosol triamcinolone acetonide further reversed airway obstruction and proved to be an effective substitute for large oral doses of steroids in steroid-dependent patients with severe asthma. No significant improvement occurred in the maximum midexpiratory flow or the maximum velocity of air flow after 50 percent or 75 percent of the vital capacity had been expelled. There was no significant difference in the frequency of untoward effects between the groups taking aerosol triamcinolone acetonide and its vehicle. No patient demonstrated any definite return of adrenal function.

Clinical and physiological assessment of asthmatic children treated with beclomethasone dipropionate

Forty-two perennial asthmatic children were selected for a 12-wk study using beclomethasone dipropionate. The groups included 21 steroid-dependent children (Group I) and 21 patients (Group II) whose disease was of sufficient severity that corticosteroid therapy was contemplated. All children received the drug in a dose of 100 mug 4 times daily. During the study, oral prednisone was withdrawn from the steroid-dependent children while other therapy was essentially unchanged. Group II children underwent a double-blind trial, receiving beclomethasone for 6 wk and placebo for 6 wk. Objective assessment of adrenal and pulmonary function was obtained at regular intervals. For the latter, total lung capacity and its subdivisions, airways resistance, maximum expiratory flow volume, and oxygen tension, were measured in both groups. In Group II static elastic recoil was measured also. For most tests the results were statistically significant. In both groups, 18 of 21 patients demonstrated an excellent clinical response, no evidence of adrenal suppression, and improvement in pulmonary function. Forty of 42 patients were followed for another 12 wk, and 19 of each group did well. After 20-24 wk of therapy, 16% of patients harbored monilia in their oropharynx, and 1 patient had clinical monilial stomatitis. Within the limits of the time of the study, beclomethasone dipropionate appeared to provide adequate clinical control in many chronic, severe, steroid-dependent and nonsteroid-dependent asthmatic children.

Beclomethasone dipropionate aerosol treatment of hay fever. A dose-response investigation

In a controlled, double-blind study 20 children and adults, suffering from summer hay fever, were treated intranasally with a daily dose of 200 mug, 300 mug or 400 mug beclomethasone dipropionate (Beconase, Becotide Nasal) or with placebo for 2 weeks during the hay fever season. No beneficial effect of the placebo treatment was observed. In patients treated with 200 mug and 300 mug beclomethasone dipropionate a day there was a moderate decrease in nasal symptom scores and in use of antihistamine tablets. As the results indicated 400 mug a day to have the most pronounced effect on nasal symptoms, this dosage is recommended for children as well as adults suffering from summer hay fever.

Double-blind cross-over trial comparing intranasal beclomethasone dipropionate and placebo in perennial rhinitis

Twenty-five patients with perennial rhinitis completed a double-blind cross-over trial of intranasal beclomethasone dipropionate 200 mug daily and placebo. Of these patients 19 preferred the active drug and two preferred placebo. There were significant reductions in symptom scores for nasal obstruction and rhinorrhoea and in the use of decongestant nasal drops when using the active drug. No changes in morning plasma cortisol levels occurred during the three-week treatment period.