Sulfasalazine for the management of juvenile rheumatoid arthritis

OBJECTIVE

Sulfasalazine (SSZ) has regulatory approval for treatment of inflammatory bowel disease in children and adults, and for use as a slow acting agent in adult rheumatoid arthritis (RA). This report surveys the literature for experience with SSZ in juvenile RA.

METHODS

Medline, Excerpta Medica, and Derwent were searched under the terms juvenile, rheumatoid, arthritis, and sulfasalazine.

RESULTS

The search found reports of experience in 550 patients, of whom about half had pauciarticular and nearly one-third polyarticular disease. The studies generally reported at least some drug associated benefit in all subtypes. Some identified late onset pauciarticular disease as most responsive, but others reported poly- and pauciarticular response rates about the same. Systemic onset disease responded poorly and showed a substantial incidence of intolerance in the form of serum sickness. Most studies showed useful disease control in spondylitis. Overall, the patterns of toxicity and intolerance were close to those seen in adult SSZ recipients, with the possible exception of the serum sickness-like response.

CONCLUSION

SSZ has demonstrated useful antirheumatic activity and can contribute to the care of selected patients.

Symmetrical bis(heteroarylmethoxyphenyl)alkylcarboxylic acids as inhibitors of leukotriene biosynthesis

Symmetrical bis(quinolylmethoxyphenyl)alkylcarboxylic acids were investigated as inhibitors of leukotriene biosynthesis and 4, 4-bis(4-(2-quinolylmethoxy)phenyl)pentanoic acid sodium salt (47.Na) met our design parameters for a drug candidate (ABT-080). This compound was readily synthesized in three steps from commercially available diphenolic acid. Against intact human neutrophils, 47.Na inhibited ionophore-stimulated LTB(4) formation with an IC(50) = 20 nM. In zymosan-stimulated mouse peritoneal macrophages producing both LTC(4) and PGE(2), 47.Na showed 9000-fold selectivity for inhibition of LTC(4) (IC(50) = 0.16 nM) over PGE(2) (IC(50) = 1500 nM). Preliminary pharmacokinetic evaluation in rat and cynomolgus monkey demonstrated good oral bioavailability and elimination half-lives of 9 and 5 h, respectively. Pharmacological evaluation of leukotriene inhibition with oral dosing was demonstrated in a rat pleural inflammation model (ED(50) = 3 mg/kg) and a rat peritoneal passive anaphylaxis model (LTB(4), ED(50) = 2.5 mg/kg; LTE(4), ED(50) = 1.0 mg/kg). In a model of airway constriction induced by antigen challenge in actively sensitized guinea pigs, 47.Na dosed orally blocked bronchoconstriction with an ED(50) = 0.4 mg/kg, the most potent activity we have observed for any leukotriene inhibitor in this model. The mode of inhibitory action of 47.Na occurs at the stage of 5-lipoxygenase biosynthesis as it blocks both leukotriene pathways leading to LTB(4) and LTC(4) but not PGH(2) biosynthesis. However, 47.Na does not inhibit 5-lipoxygenase catalysis in a broken cell enzyme assay; therefore it is likely that 47.Na acts as a FLAP inhibitor.

Heteroarylmethoxyphenylalkoxyiminoalkylcarboxylic acids as leukotriene biosynthesis inhibitors

A novel series of heteroarylmethoxyphenylalkoxyiminoalkylcarboxylic acids was studied as leukotriene biosynthesis inhibitors. A hypothesis of structure-activity optimization by insertion of an oxime moiety was investigated using REV-5901 as a starting point. A systematic structure-activity optimization showed that the spatial arrangement and stereochemistry of the oxime insertion unit proved to be important for inhibitory activity. The promising lead, S-(E)-11, inhibited LTB(4) biosynthesis in the intact human neutrophil with IC(50) of 8 nM and had superior oral activity in vivo, in a rat pleurisy model (ED(50) = 0.14 mg/kg) and rat anaphylaxis model (ED(50) = 0.13 mg/kg). In a model of lung inflammation, S-(E)-11 blocked LTE(4) biosynthesis (ED(50) of 0.1 mg/kg) and eosinophil influx (ED(50) of 0.2 mg/kg). S-(E)-11 (A-93178) was selected for further preclinical evaluation.

Improving the in vivo duration of 5-lipoxygenase inhibitors: application of an in vitro glucuronosyltransferase assay

An in vitro glucuronidation assay was used to optimize a series of N-hydroxyurea-containing 5-lipoxygenase inhibitors for metabolic stability. The glucuronidation of these compounds in cynomolgus monkey microsomes followed Michaelis-Menten kinetics allowing calculation of V(max) and K(M). The V(max) values ranged from 0.02 to 7.9 nmol/min/mg microsomal protein, a 400-fold difference, whereas K(M) ranged from 204 to 2500 microM, only a 12-fold difference. In vitro intrinsic clearance values (CL(int) were calculated for 18 compounds tested in the kinetic assay and compared with the in vivo plasma clearance (CL(p)) calculated from intravenous studies done in cynomolgus monkeys. These initial results suggested a relationship between the in vitro CL(int) and in vivo duration as defined by CL(p). A more rapid in vitro assay was developed in a 96-well format using a single concentration of substrate (100 microM) from which a glucuronidation rate was calculated. The results from this assay for 40 compounds correlated with in vivo plasma clearance (r = 0.57). This more efficient assay was used to test more than 100 compounds and develop structure-metabolism relationships based on metabolic stability and improved duration. The culmination of this effort contributed to the discovery of ABT-761, a 5-lipoxygenase inhibitor with in vivo duration in monkey improved 40-fold over thefirst generation inhibitor. Further studies performed in human liver microsomes demonstrated a similar trend that was corroborated by the 8-fold increase in duration after oral dosing in humans observed with ABT-761.

Structure-activity relationships of N-hydroxyurea 5-lipoxygenase inhibitors

The discovery of second generation N-hydroxyurea 5-lipoxygenase inhibitors was accomplished through the development of a broad structure-activity relationship (SAR) study. This study identified requirements for improving potency and also extending duration by limiting metabolism. Potency could be maintained by the incorporation of heterocyclic templates substituted with selected lipophilic substituents. Duration of inhibition after oral administration was optimized by identification of structural features in the proximity of the N-hydroxyurea which correlated to low in vitro glucuronidation rates. Furthermore, the rate of in vitro glucuronidation was shown to be stereoselective for certain analogs. (R)-N-[3-[5-(4-Fluorophenoxy)-2-furyl]-1-methyl-2-propynyl]-N-hydroxyure a (17c) was identified and selected for clinical development.

Pharmacokinetic and pharmacodynamic assessment of bioavailability for two prodrugs of methylprednisolone

AIMS

The aim of this study was to establish whether pharmacokinetic differences between two pro-drugs of methylprednisolone (MP) are likely to be of clinical significance.

METHODS

This study was a single-blind, randomized, crossover design comparing the bioequivalence of MP released from the pro-drugs Promedrol (MP suleptanate) and Solu-Medrol (MP succinate) after a single 250 mg (MP equivalent) intramuscular injection to 20 healthy male volunteers. Bioequivalence was assessed by conventional pharmacokinetic analysis, by measuring pharmacodynamic responses plus a novel approach using pharmacokinetic/pharmacodynamic modeling. The main measure of pharmacodynamic response was whole blood histamine (WBH), a measure of basophil numbers.

RESULTS

The MP Cmax was less for MP suleptanate due to a longer absorption halflife of the prodrug from the intramuscular injection site. The bioavailability of MP was equivalent when based on AUC with a MP suleptanate median 108% of the MP succinate value (90% CI: 102-114%). For Cmax the MP suleptanate median was 81% of the MP succinate value (90% CI: 75-88%). The tmax for MP from MP suleptanate was delayed relative to MP succinate. The median difference was 200% (90% non-parametric CI: 141-283%). The area under the WBH effect-time curve (AUEC) and the maximum response (Emax) were found to be equivalent (90% CI: 98-113% and 93-109% respectively). The maximum changes in other white blood cell counts, blood glucose concentration and the parameters of the pharmacodynamic sigmoid Emax model (EC50, Emax and gamma) were also not significantly different between prodrugs.

CONCLUSIONS

MP suleptanate is an acceptable pharmaceutical alternative to MP succinate. The use of both pharmacokinetic and pharmacodynamic response data together gives greater confidence in the conclusions compared with those based only on conventional pharmacokinetic bioequivalence analysis.

Effect of systemic corticoid and antihistamine alone or in combination on elements of the response to a two dose nasal allergen challenge

This study examined the effects of low dose systemic corticoid (methylprednisolone, MP), standard dose antihistamine (terfenadine, TF) or the combination on response to out-of-season acute allergen challenge. We feel that a single dose challenge delivered to the nose may represent real disease imperfectly and in this study used two doses given 1 hour apart, hoping to approximate better the circumstances of natural allergen stimulation. The study used clinical endpoints only: measured nasal airway resistance (NAR), sneeze count, and weight of blown nasal secretions. Subjects showed similar NAR, sneezing, and secretion response to both challenges. With placebo treatment, NAR rose after the first allergen provocation and returned to baseline about 30 minutes later. Antihistamine pretreatment appeared to delay but did not prevent this rise; low dose corticoid partially inhibited it, and the combination totally ablated the response. All active treatments suppressed sneezing and secretion better than placebo. Combination corticoid/antihistamine treatment showed no greater effect on sneeze/ secretion than did antihistamine alone; this differs from our findings in separate studies comparing analogous drug combinations in naturally-acquired ragweed hayfever.

Synthesis of indolylalkoxyiminoalkylcarboxylates as leukotriene biosynthesis inhibitors

A series of substituted indolylalkoxyiminoalkylcarboxylates were found to be potent leukotriene biosynthesis inhibitors. The structure-activity relationships were investigated. Representative potent inhibitors identified were the quinolyl 3a (A-86885) and pyridyl 3b (A-86886) congeners with in vitro IC50s of 21 and 9 nM and in vivo leukotriene inhibition in the rat with oral ED50s of 0.9 and 1.7 mg/kg, respectively.

ABT-761 attenuates bronchoconstriction and pulmonary inflammation in rodents

Our primary goal has been to discover leukotriene biosynthesis inhibitors with characteristics that are appropriate for use as clinical agents. The success of the use of zileuton in the treatment of asthma led us to explore further the use of the N-hydroxyurea class of 5-lipoxygenase inhibitors as longer-acting compounds with good lung penetration. A variety of in vitro and in vivo methods were used to evaluate a large number of compounds, from which ABT-761 [(R)-N-(3-(5-(4-fluorophenylmethyl)thien-2-yl)-1-methyl-2-pr opynyl)-N-hydroxyurea] was selected for study. ABT-761 exhibited potent and selective inhibition of leukotriene formation both in vitro and in vivo. More importantly, the compound potently inhibited antigen-induced bronchospasm in guinea pigs when given either prophylactically or therapeutically. In addition, ABT-761 was a potent inhibitor of eosinophil influx into the lungs of Brown Norway rats. These data provide added support for the role of leukotrienes in both bronchospasm and eosinophilic inflammation and characterize ABT-761 as a particularly potent inhibitor of leukotrienes formed in pulmonary tissues. These data combined with the excellent pharmacokinetic characteristics of the compound indicate its potential use in the treatment of leukotriene-dependent human disease.

Nonsteroidal anti-inflammatory drugs as scaffolds for the design of 5-lipoxygenase inhibitors

Representative nonsteroidal anti-inflammatory drug (NSAID) cyclooxygenase inhibitors such as ibuprofen, naproxen, and indomethacin were used as orally bioavailable scaffolds to design selective 5-lipoxygenase (5-LO) inhibitors. Replacement of the NSAID carboxylic acid group with a N-hydroxyurea group provided congeners with selective 5-LO inhibitory activity.

Conversion of cyclooxygenase inhibitors into hydroxythiazole 5-lipoxygenase inhibitors

Representative examples of NSAID cyclooxygenase inhibitors such as naproxen, ibufenac, ibuprofen, and butibufen have been transformed into 5-lipoxygenase inhibitors by replacement of the carboxylic acid moiety with a 4-hydroxythiazole group.

5-Lipoxygenase inhibitors: synthesis and structure-activity relationships of a series of 1-aryl-2H,4H-tetrahydro-1,2,4-triazin-3-ones

Synthetic routes were developed to access a variety of novel 1-aryl-2H,4H-tetrahydro-1,2,4-triazin-3-one analogs which were evaluated as 5-lipoxygenase (5-LO) inhibitors. The parent structure, 1-phenylperhydro-1,2,4-triazin-3-one (4), was found to be a selective inhibitor of 5-LO in broken cell, intact cell, and human blood assays with IC50 values of 5-21 microM. In a rat anaphylaxis model, 4 blocked leukotriene formation with an ED50 = 7 mg/kg when administered orally. Compound 4 exhibited selectivity for inhibition of 5-LO with little activity against related enzymes: 12-LO from human platelets, 15-LO from soybean, and cyclooxygenase (COX) from sheep seminal vesicle. In pilot subacute toxicity testing, 4 did not produce methemoglobinemia in rats (400 mg/kg po daily for 9 days) or in dogs (200 mg/kg po daily for 28 days). These results indicated that the triazinone structure provided a 5-LO inhibitor template devoid of the toxicity problems observed in the related phenidone (1) and pyridazinone (3) classes of 5-LO inhibitors. The parent compound 4 is a selective, orally bioavailable 5-LO inhibitor which can serve as a useful reference standard for in vivo pharmacological studies involving leukotriene-mediated phenonmena.

Leukotrienes do not regulate nitric oxide production in RAW 264.7 macrophages

RAW 264.7 macrophages respond to lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) by producing large amounts of nitric oxide (NO) and prostaglandin E2 (PGE2), with maximal production 18-24 h after treatment. Following stimulation with the calcium inophore A23187, cultures of RAW cells also produce modest amounts of leukotrienes. However, the capacity of these cells to produce leukotrienes is transient, beginning 2 h after vehicle or LPS/IFN-gamma treatment, peaking by 4-6 h and absent by 8 h. A-79175, (R(+) N-[3-[5-(4-Fluorophenoxy)-2-furanyl]-1-methyl-2-propynyl]-N-hydroxyurea) a specific inhibitor of 5-lipoxygenase (5-LO), abolished leukotriene production by RAW cells in a dose-dependent, non-cytotoxic fashion while having no effect on PGE2 or NO production. By contrast, nordihydroguaiaretic acid (NDGA) inhibited production of leukotrienes, PGE2 and NO only at doses that were cytotoxic to the RAW cells. Exogenous leukotriene B4 (LTB4) had no effect on either NO or PGE2 production. An inhibitor of NO production, L-N-5-(1-iminoethyl) ornithine HCl (NIO) also did not affect leukotriene or PGE2 production, while dexamethasone blocked PGE2 and NO production, but did not affect leukotriene production in these cells. Taken collectively, these results indicate that there is no interaction between the pathways for leukotriene and nitric oxide production in RAW 264.7 macrophages.

(R)-(+)-N-[3-[5-[(4-fluorophenyl)methyl]-2-thienyl]-1-methyl- 2-propynyl]-N-hydroxyurea (ABT-761), a second-generation 5-lipoxygenase inhibitor

Structure-activity optimization of inhibitory potency and duration of action of N-hydroxyurea containing 5-lipoxygenase inhibitors was conducted. The lipophilic heteroaryl template and the link group connecting the template to the N-hydroxyurea pharmacophore were modified. Inhibition of 5-lipoxygenase was evaluated in vitro in a human whole blood assay. An in vitro assay using liver microsomes from monkey was used to evaluate congeners for comparative rates of glucuronidation. (3-Heteroaryl-1-methyl-2-propynyl)-N-hydroxyureas were found to be more resistant to in vitro glucuronidation. The promising inhibitor N-[3-[5-(4-fluorophenoxy)-2-furyl]-1-methyl-2-propynyl]-N- hydroxyurea (6) was found to have stereoselective glucuronidation in monkey and man. The R enantiomer 7 provided longer duration of inhibition as evaluated by an ex vivo whole blood assay. Further optimization of the lipophilic template led to the discovery of (R)-(+)-N-[3-[5-[(4-fluorophenyl)methyl]-2- thienyl]-1-methyl-2-propynyl]-N-hydroxyurea (11) with more effective and prolonged inhibition of leukotriene biosynthesis than zileuton (1) and 7 in monkey and man. The optimized 5-lipoxygenase inhibitor 11 was selected for development as an investigational drug for leukotriene-mediated disorders.

Effect of vasoconstrictor pre-treatment on obstruction, secretion and sneezing after nasal challenge with threshold and suprathreshold allergen doses

Acute nasal allergen challenge produces airway obstruction which varies in amount and timing with the allergen dose delivered. To see whether different mechanisms might contribute variably to mucosal swelling with different amounts of allergen, we challenged sensitive volunteers with threshold and 10-times threshold allergen doses, with and without topical vasoconstrictor pre-treatment. The vasoconstrictor effectively eliminated obstruction at both allergen dose levels, suggesting that acute vascular changes were responsible for all the measurable obstruction seen with acute allergen provocation. Alpha-adrenergic vasoconstrictor pre-treatment was associated with increased weight of secretion and numbers of sneezes.

Oral methylprednisolone acetate (Medrol Tablets) for seasonal rhinitis: examination of dose and symptom response

The authors compared the effect of several doses an oral corticosteroid on symptom profile and severity in ragweed hay fever. Thirty-one patients were randomized to receive 0, 6, 12, or 24 mg methylprednisolone (Medrol Tablets [MP], Upjohn, Kalamazoo, MI). A baseline week in which no treatment was given preceded the treatment comparison. At the end of this week, symptom diaries showed that most of the subjects were experiencing moderate or severe symptoms. The corticoid produced dose-related reduction in all symptoms. The difference between placebo and 24 mg MP was significant for all the symptoms monitored, except itching, which benefited marginally. With 6 mg MP, congestion, drainage, and eye symptoms showed significant drug-placebo differences but itching, running/blowing, and sneezing did not. Not all rhinitis symptoms responded equally to corticoid treatment. Those that responded least could reflect histamine effect, which was not effectively suppressed by low-dose, short-term corticoid treatment.

Unilaterality of obstruction after acute nasal allergen provocation. Relation of allergen dose, nasal reactivity and the nasal cycle

We examined unilaterality of obstruction after acute bilateral nasal allergen provocation in two groups of pollen-sensitive volunteers studied out of season. One group was challenged on one occasion with a threshold allergen dose and on another with placebo. We measured nasal airway resistance (NAR) unilaterally for 3.5 hr before the challenges and for 40 min after. Most subjects' noses had marked asymmetry of response. Over half showed marked obstruction on one side and none at all on the other side. The side which showed higher resistance and greater lability before challenge was typically more obstructed after. In a second group we compared responses to threshold and x 10 threshold doses. Threshold challenge produced results similar to those seen with the first group. After the higher allergen dose, there was some obstruction in the less responsive side and the rate of rise was much slower. Obstructive response after acute threshold allergen challenge is typically one-sided. This pattern may be related to the stage of the nasal cycle in which the challenge was delivered. Higher allergen doses produce more obstruction in the less responsive side but the response is still asymmetrical.

Clinical safety of flurbiprofen

Data from 58 premarketing studies of the nonsteroidal antiinflammatory drug flurbiprofen were pooled for analyses of adverse drug reactions (ADRs). These studies included 5602 patients treated with flurbiprofen (N = 4123), aspirin (N = 1033), or placebo (N = 446) for varying durations. Diagnoses included rheumatoid arthritis, osteoarthritis, and other painful musculoskeletal conditions. In these studies serious upper gastrointestinal ADRs occurred in flurbiprofen-treated patients at less than one half the rate seen in aspirin-treated patients. The incidence of serious urinary tract ADRs was lower with flurbiprofen than with aspirin. The flurbiprofen group had no serious clinical ADRs related to the hemic/lymphatic system. The most common laboratory abnormality was a decrease in hematocrit, which occurred less often than in the aspirin group. We also evaluated serious flurbiprofen-related ADRs in 4370 patients in a variety of other studies and reviewed published reports of flurbiprofen clinical trials and case reports. These reviews showed no additional, unanticipated patterns of intolerance. These clinical safety data indicate that in the doses studied, flurbiprofen is a well tolerated agent for patients requiring nonsteroidal antiinflammatory drug therapy.

Profile of ragweed hay fever symptom control with terfenadine started before or after symptoms are established

Forty-two ragweed hay fever patients participated in a study which examined the profile of symptom relief provided by terfenadine, and the relative adequacy of symptom control with the drug given from the beginning of the season compared with treatment started after symptoms were well established. Compared with placebo, terfenadine effectively relieved sneeze, itch and eye symptoms. It had no effect on running, blowing and drainage. Subjectively perceived congestion benefited marginally. When the drug was begun after symptoms were well established, sneezing responded quickly and maximally. Eye discomfort lessened but not to the level experienced by those dosed from the beginning of the season. The pattern in other symptom categories was less clear. Overall, terfenadine improved all rhinitis symptoms except those related to hypersecretion. Some symptoms appeared to respond better when drug dosing commenced at the beginning of the season.

Vasoconstrictor and corticosteroid responsive components of allergic nasal mucosal swelling

This study evaluated the relative contributions of vascular engorgement and less reversible components of inflammation (edema, cellular infiltration) to production of allergic nasal congestion. We established the minimum nasal airway resistance (NAR) inducible by oxymetazoline spray in 29 asymptomatic patients. During ragweed season, we restudied them with the same decongestant regimen before and after 1 week of treatment with oral methylprednisolone (Medrol tablets, Upjohn) or a matched placebo. It was not possible, in the conditions of this study, to decongest symptomatic patients to baseline using only the topical vasoconstrictor. This could be accomplished in those receiving methylprednisolone. Corticoid therapy relieved a non-vascular component of congestion or rendered vasoconstrictor therapy more effective.

Hay fever treatment with combined antihistamine and cyclooxygenase-inhibiting drugs

Twenty-eight ragweed-allergic patients with hay fever participated in a clinical trial that examined the pattern of symptom relief resulting from addition of a cyclooxygenase-inhibiting drug to standard antihistamine therapy. In the first week antihistamine use by the subjects was standardized, and subjects were oriented to use of the hay fever symptom diary. They were then allocated, according to symptom severity, to two treatment groups. One group received 120 mg of terfenadine and 300 mg of flurbiprofen (a cyclooxygenase-inhibiting drug) per day. Members of the other group received terfenadine and a placebo that looked like flurbiprofen. This treatment lasted 1 week. Subjects recorded severity of congestion, drainage, running, nose blowing, itching, and sneezing four times each day. The flurbiprofen-treated patients experienced less severe symptoms, demonstrating maximum benefit 3 to 5 days into the drug trial with some loss of effect thereafter. Secretion-related symptoms appeared to benefit most. Combined blockade of histamine and cyclooxygenase products appears to offer improved symptom control in ragweed hay fever.

Nasal airway response to infused phenylephrine in normals and in patients with allergic and non-allergic rhinitis

To find whether patients with chronic rhinitis might be congested because of hyporesponsiveness to adrenergic vasoconstrictive influences, we measured nasal airway resistance (NAR) in normals and allergic and non-allergic rhinitics during intravenous infusion of graded doses of phenylephrine. All responded with decreases in NAR and first evidences of NAR fall appeared no later in those with rhinitis than in normals. Nasal congestion and response were asymmetrical; absolute NAR in the low resistance side was similar in all groups and there was little response to phenylephrine. In the high resistance side, NAR reached its minimum by the time the total infused dose was 1400 mcg, indicating maximum response to drug was achieved within the dose range studied. Minimum NAR achieved on the high resistance side was higher in rhinitics suggesting residual vascular engorgement resistant to phenylephrine or non-vascular mucosal swelling. Resistance to adrenergic vasoconstriction does not appear to be the primary contributor to mucosal swelling in chronic rhinitis.

Effect of intranasal histamine on nasal mucosal blood flow and the antidiuretic activity of desmopressin

The effects of exogenous histamine on nasal mucosal blood flow and the systemic activity of intranasally administered desmopressin, a vasopressin analogue, were studied in normal volunteers. Ten subjects received either saline or histamine (1, 20, 100, and 500 micrograms) by intranasal spray. Maximal nasal mucosal blood flow response, determined by laser doppler velocimetry, demonstrated a significant (P less than 0.05) linear relationship to histamine dose. Eight additional subjects received each of the following intranasal treatments: 20 micrograms histamine followed by 10 micrograms desmopressin; normal saline followed by 10 micrograms desmopressin; 20 micrograms histamine followed by vehicle; or normal saline and vehicle. Nasal blood flow was determined before and after each treatment. Desmopressin activity was assessed by measuring urine osmolality, flow rate, electrolyte, and creatinine concentration for 24 h after each treatment. The effect of histamine and desmopressin was greater than desmopressin alone, with respect to nasal blood flow response (103 +/- 24 vs. 4 +/- 17%, mean +/- SEM, P less than 0.02), initial urine osmolality (520 +/- 123 vs. 333 +/- 75 mosM, P less than 0.03), urine electrolyte (potassium, 45 +/- 11 vs. 28 +/- 7 meq/liter; sodium, 68 +/- 21 vs. 36 +/- 8 meq/liter, P less than 0.03) and creatinine concentrations (95 +/- 23 vs. 60 +/- 13 mg/dl, P less than 0.03), and the duration of decrease in urine flow rate compared with saline and vehicle. These results suggest that the systemic activity of intranasal desmopressin is enhanced by increasing local nasal blood flow and are consistent with increased transnasal absorption of the peptide.

Pharmacokinetics of flurbiprofen

Both radiolabeled and nonlabeled drug have been used to study the pharmacokinetics of flurbiprofen (Ansaid, Upjohn). Drug absorption is rapid, drug disappearance half-life is independent of oral dose, and the area under the plasma drug concentration versus time curve increases with increasing oral dose. Elimination of intact drug from the peripheral circulation is biphasic and rapid. Following a single oral dose of 100 mg of flurbiprofen, drug bioavailability is equivalent using regimens of four 25-mg tablets, two 50-mg tablets, or one 100-mg tablet once daily. Long-term administration of flurbiprofen appears neither to inhibit nor induce the drug's metabolism.

Attenuation of protection with repeated cromolyn dosing before exercise challenge in subjects with asthma

Though cromolyn sodium exhibits tachyphylaxis in laboratory models of allergy, this pattern has not been identified in clinical use or in human asthma provocation models. We looked for it using a treadmill exercise challenge scheme that had previously confirmed cromolyn's protective effect. Twelve exercise-sensitive asthmatic volunteers received in random order, 12 20-mg cromolyn inhalations, 12 placebo inhalations, and 11 placebo inhalations with a final 20-mg dose of cromolyn. Each regimen was given over a three-day period, with the final dose administered 30 minutes before exercise. Subjects' respiratory functions were measured before and repeatedly after exercise with body plethysmography and peak flow rates. Beginning six minutes after the end of exercise, parameters measured after single-dose cromolyn and placebo administration differed in all endpoints at most of the measurement intervals. Results with 12-dose cromolyn pretreatment were significantly different from those seen with placebo only at 40 minutes after exercise, whereas single- and multiple-dose cromolyn results differed at 20 and 30 minutes. Cromolyn accelerated recovery from exercise-induced falls in lung function; this effect was attenuated with multiple dosing. These results are consistent with development of tachyphylaxis.

Treatment of ragweed hay fever with flurbiprofen, a cyclooxygenase-inhibiting drug

Sixty-two volunteer hay fever patients participated in a 2-week trial which examined the protective effect of the cyclooxygenase-inhibiting drug flurbiprofen. The drug suppressed symptom severity significantly, though it was not as protective as the antihistamine also employed in the trial. Flurbiprofen's effects suggests that prostaglandin release may contribute to the symptoms of allergic rhinitis.

Delayed onset of infectious mononucleosis associated with acquired agammaglobulinemia and red cell aplasia

In 1974, an 11-year-old white boy with the X-linked lymphoproliferative syndrome developed hyper-IgM after becoming infected with Epstein-Barr virus. However, he failed to develop normal immune responses against the virus. In December 1981, when red cell aplasia occurred, he was given packed erythrocytes and gammaglobulin. Nine weeks later, acute infectious mononucleosis developed. Concurrently, his T4/T8 helper/suppressor ratio decreased from 2.7 to 0.2, and IgM antibodies to Epstein-Barr virus appeared. Subsequently, circulating B cells became undetectable in his blood, and agammaglobulinemia appeared. Red cell aplasia abated transiently. This patient's course was complicated by Haemophilus influenzae and Mycobacterium tuberculosis pneumonias, and red cell aplasia and agammaglobulinemia have persisted. Epstein-Barr virus acting as a slow virus probably induced the red cell aplasia and agammaglobulinemia because of the aberrant immune responses to Epstein-Barr virus. Immunodeficient responses to Epstein-Barr virus should be sought in other patients with the diseases documented in our patient.

Effect of flurbiprofen, a cyclooxygenase inhibiting drug, on induced allergic rhinitis

To test whether prostaglandins contribute to the nasal allergic reaction, we subjected allergic rhinitis patients to nasal allergen challenge after treatment with flurbiprofen, a cyclooxygenase inhibitor. We challenged 18 patients after two pretreatment doses of flurbiprofen, 75 mg, chlorpheniramine, 6 mg, both drugs combined, and placebo. All patients received all treatments. None of the treatments affected measured nasal airway resistance. Nasal secretion weight, number of sneezes, and overall subjective severity scores for all active treatments differed significantly from placebo treatment. Flurbiprofen proved nearly as effective as chlorpheniramine in reducing severity of induced rhinitis. Some mechanism that can be influenced by flurbiprofen (possibly prostaglandin synthesis) contributes to the acute, induced allergic reaction.

Protective effect of hydroxyzine and phenylpropanolamine in the challenged allergic nose

Allergic rhinitis patients were challenged with intranasal allergen aerosols after pretreatment with hydroxyzine and phenylpropanolamine, singly and in combination. Hydroxyzine protected against itching, sneezing and hypersecretion but aggravated obstruction. Phenylpropanolamine had a subtle but measurable anti-congestive effect. This model quantitates and confirms the complementary effects of combined antihistamine-decongestant therapy.

Effect of ibuprofen or aspirin on probenecid-induced uricosuria

We dosed eight normal volunteers with single doses of probenecid alone and with aspirin or ibuprofen. Urinary urate clearance was increased by probenecid. This increase was partially inhibited by aspirin but not by ibuprofen.

Ibuprofen in osteoarthritis

In a double-blind, multiclinic study, 437 patients with osteoarthritis were treated sequentially with ibuprofen, 1,800 mg/day, and placebo, or with aspirin, 3,600 mg/day, and placebo. Each treatment was given for four weeks. Considering relief of pain, ability to function, and general well-being, the patients preferred drug to placebo, usually by a statistically significant margin. Combined results showed no significant differences between ibuprofen and aspirin. Patients' evaluations of exercise-related pain, ability to perform a selected activity, and total discomfort and disability, and physicians' evaluations of discomfort and disability, all favored drug over placebo, and the differences were significant for a number of endpoints. The results indicated ibuprofen, 1,800 mg/day, offers about the same antiarthritic benefit as aspirin, 3,600 mg/day. Both drugs are superior to placebo. The incidence of gastrointestinal complaints with ibuprofen was similar to that with placebo and significantly lower than that with aspirin.

Ibuprofen and visual function. Prospective evaluation

Eye evaluations before and after 24 weeks of treatment with either ibuprofen (Motrin) or aspirin did not show eye toxicity with either drug in a double-blind study of 78 patients with osteoarthritis. The possibility of eye complications resulting from ibuprofen therapy suggested in two earlier reports has not been confirmed in clinical usage in other countries or in clinical trials in the United States.

Ibuprofen or aspirin in rheumatoid arthritis therapy

Ibuprofen is a nonsteroidal drug with analgesic, antipyretic, and anti-inflammatory properties that was recently introduced for use in antiarthritis therapy in the United States. In a year-long double-blind multiclinic trial in 885 patients with rheumatoid arthritis, ibuprofen was at least as satisfactory as aspirin, considering both efficacy and tolerance. In the majority of patients, daily doses ranged from 800 to 1,600 mg of ibuprofen and 3 to 6 gm of aspirin. The drugs did not differ greatly in providing relief from arthritis symptoms, but ibuprofen was definitely better tolerated, especially in regard to gastrointestinal complaints. Seven percent of the ibuprofen group dropped out of the study because of adverse reactions, as compared with 16% of the aspirin group; 17% of the ibuprofen group and 31% of the aspirin group had gastrointestinal symptoms.