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PubMed1995

Tenidap in rheumatoid arthritis. A 24-week double-blind comparison with hydroxychloroquine-plus-piroxicam, and piroxicam alone.

OBJECTIVE: To compare the clinical efficacy, effect on serum C-reactive protein (CRP), serum amyloid A (SAA), and plasma interleukin-6 (IL-6) levels, and safety of tenidap with a combination of hydroxychloroquine-plus-piroxicam, and piroxicam alone, in the treatment of rheumatoid arthritis (RA) patients. METHODS: A double-blind, randomized, multicenter study in which patients with active RA were treated with tenidap 120 mg/day, hydroxychloroquine 400 mg/day and piroxicam 20 mg/day, or piroxicam alone 20 mg/day, for 24 weeks. RESULTS: At weeks 12 and 24, tenidap produced greater improvements than piroxicam based on 5 primary efficacy parameters; this improvement showed statistical significance in 4 of the 5 measures at week 12, and in 3 of the 5 measures at week 24. Clinical improvements in the hydroxychloroquine-plus-piroxicam-treated with tenidap. Compared with piroxicam, tenidap was associated with significantly greater reductions in serum CRP concentrations at 4, 12, and 24 weeks, and significantly greater reductions in SAA concentrations at weeks 12 and 24. The decrease in SAA concentrations was also significantly greater at weeks 4 and 24 in the tenidap-treated group than in the hydroxychloroquine-plus-piroxicam-treated group. Significant reductions in plasma IL-6 levels were observed at weeks 4, 12, and 24 within the tenidap group, and at week 24 within the hydroxychloroquine-plus-piroxicam-treated group. The overall occurrence of side effects, including gastrointestinal side effects, was similar in all 3 treatment groups. A small proportion of tenidap-treated patients (6.4%) manifested mild, nonprogressive, reversible proteinuria of presumed renal proximal tubular origin, and 3-4% of patients had elevated transaminase levels. CONCLUSION: In the treatment of patients with RA, tenidap is as effective as the combination of hydroxychloroquine-plus-piroxicam, and is more effective than piroxicam alone; moreover, tenidap's safety profile is comparable to that observed with piroxicam alone, and with hydroxychloroquine-plus-piroxicam. The clinical response observed in this study, as well as the prompt decreases in acute-phase protein levels of CRP and SAA, and in plasma IL-6 levels, suggest that tenidap represents a new type of antiarthritic medication, with properties similar to, but not identical to, a therapeutic combination of a nonsteroidal antiinflammatory drug with disease-modifying antirheumatic drugs.

Adult↗
PubMed1988

Treatment of primary Sjögren's syndrome with hydroxychloroquine.

Sjögren's syndrome is an autoimmune disease characterized by lymphocytic infiltration of the salivary/lacrimal glands, autoantibody production, and polyclonal hyperglobulinemia. In view of the efficacy and relative safety of hydroxychloroquine in other autoimmune disorders, the potential benefit of hydroxychloroquine (200 mg per day for 12 months) in 10 patients with Sjögren's syndrome was evaluated. Changes in levels of total immunoglobulin, antibody against Sjögren's syndrome-associated antigen B, rheumatoid factor, and in vitro production of immunoglobulin in the serum were evaluated. For comparison, 10 patients matched according to age and sex, who did not receive hydroxychloroquine were studied. In the hydroxychloroquine-treated group, the following observations were made: (1) significantly decreased total immunoglobulin G (IgG) and IgA levels with little change in IgM levels; (2) significant decrease in IgA-rheumatoid factor with a smaller decrease in IgM-rheumatoid factor; (3) decreased IgG anti-Sjögren's syndrome-associated antigen B autoantibody; and (4) decreased erythrocyte sedimentation rate and increased hemoglobin level. Further, a specific idiotype present on their rheumatoid factor (defined by monoclonal antibody 17-109) was significantly decreased, with disappearance of detectable circulating paraprotein in two hydroxychloroquine-treated patients. Finally, rheumatoid factor production in vitro by lymphocytes from hydroxychloroquine-treated patients using a T cell-dependent mitogen was significantly decreased. These results suggest that hydroxychloroquine modulates lymphoproliferation in patients with Sjögren's syndrome and may prevent progression to extraglandular sites of neoplastic transformation.

Autoantibodies↗
PubMed1988

Hydroxychloroquine in steroid dependent asthma.

A recent case report suggested that hydroxychloroquine had a steroid sparing effect in a patient with severe chronic asthma. We have studied the effect of hydroxychloroquine in a group of nine steroid dependent adult asthmatic patients using a randomised double blind crossover comparison of hydroxychloroquine and placebo. Each patient received hydroxychloroquine (400 mg/day) or placebo for 2 month periods. The effect of hydroxychloroquine or placebo on asthma control was assessed by change in steroid dosage, visual analogue symptom scores, response to beta 2 agonist and peak expiratory flow rate (PFR) measurement. The dose of prednisolone required during hydroxychloroquine treatment did not differ from that during placebo treatment or in pre-trial period. There was no significant change in symptom scores of PFR measurement. In this study an 8 week treatment with hydroxychloroquine was of no benefit to patients with chronic steroid dependent asthma.

Adult↗
PubMed2004

Impact of hydroxychloroquine therapy on chronic urticaria: chronic autoimmune urticaria study and evaluation.

BACKGROUND: Chronic urticaria (CU) imposes profound impairment on quality of life. Up to 60% of idiopathic CU is associated with autoimmune phenomena, and may respond to immunomodulation. Hydroxychloroquine offers potential efficacy for CU and is relatively benign compared with most other therapeutic approaches. OBJECTIVE: The aim of the chronic autoimmune urticaria study and evaluation was to evaluate the efficacy of hydroxychloroquine in patients with chronic idiopathic urticaria. METHODS: Twenty-one patients referred to the Immunology and Allergy Unit at John Hunter Hospital, New South Wales, Australia, with idiopathic CU were randomised to receive treatment with standard urticaria therapies (corticosteroids, H2-antihistamines, H1--antihistamines, doxepin) with or without hydroxychloroquine. Markers of autoimmunity, thyroid disease and mast-cell autoreactivity (autologous serum skin-prick testing (ASPT)) were assessed. Measures of urticaria control were compared at baseline and at 12 weeks for the 18 individuals who completed the study. These included urticaria scores, medication scores and quality-of-life indices. RESULTS: The hydroxychloroquine-treated group achieved significant improvements in quality of life as assessed by the global symptom severity score and the LAMY-7 (a quality of life index designed by Lamy, 7th revision) at 12 weeks (P < 0.01 and P < 0.05, respectively). No significant treatment effect on medication requirements or urticaria score was detected, although differences between treatment groups approached statistical significance for urticaria score and medication requirements (0.05 < P < 0.10). ASPT-reactivity did not correlate to hydroxychloroquine-responsiveness. Hydroxychloroquine was well tolerated. CONCLUSION: Immunomodulation with hydroxychloroquine is safe and appears to offer some efficacy as an intervention in CU.

Adult↗
PubMed1990

Hydroxychloroquine in decompensated, treatment-refractory noninsulin-dependent diabetes mellitus. A new job for an old drug?

STUDY OBJECTIVE: To evaluate the usefulness and safety of hydroxychloroquine in patients with decompensated, treatment-refractory noninsulin-dependent diabetes mellitus. DESIGN: Prospective, randomized, placebo, double-blind 6-month trial. PATIENTS: Thirty-eight patients with noninsulin-dependent diabetes resistant to commonly used therapies (oral drugs, insulin, combination of insulin and oral drugs). INTERVENTIONS: Two study groups: one received insulin (n = 22) and the other, glibenclamide (n = 16). In each group, half of the patients were randomly allocated into two subgroups who continued the previous treatment but took either placebo tablets or hydroxychloroquine, 200 mg three times a day. The four subgroups were as follows: insulin and placebo (n = 11); insulin and hydroxychloroquine (n = 11); glibenclamide and placebo (n = 8); and glibenclamide and hydroxychloroquine (n = 8). MEASUREMENTS AND MAIN RESULTS: At 6 months, relevant and statistically significant improvement occurred in the 11 patients who received the insulin and hydroxychloroquine (glucose profile decrease, -11.7 mmol/L; 95% CI, -13.9 to -9.5, P = 0.001; glycated hemoglobin A1c decrease, -3.3%; 95% CI, -3.9 to -2.7, P = 0.001). No significant changes were seen in patients on placebo. The daily insulin dose in patients treated with the combined insulin and hydroxychloroquine therapy had to be reduced an average of 30%. No important side effects were detected. CONCLUSIONS: Combining antidiabetic therapy with hydroxychloroquine in decompensated, treatment-refractory patients with noninsulin-dependent diabetes may help to break the vicious circle of hyperglycemia and lead to better management of the disease.

Adult↗
PubMed1997

Chloroquine and hydroxychloroquine equally affect tumor necrosis factor-alpha, interleukin 6, and interferon-gamma production by peripheral blood mononuclear cells.

OBJECTIVE: The efficacy of both chloroquine and hydroxychloroquine in rheumatoid arthritis (RA) has been proved in controlled clinical trials. Despite similar chemical characteristics, it is believed the clinical efficacy of chloroquine is superior to that of hydroxychloroquine in patients with RA. Excessive production of proinflammatory cytokines was shown to contribute to the pathogenesis of RA. From different studies testing either chloroquine or hydroxychloroquine, it could be concluded that both drugs differentially inhibit cytokine production. METHODS: We compared the effects of both chloroquine and hydroxychloroquine on stimulated peripheral blood mononuclear cells (PBMC) with respect to cytokine production. Therefore, PBMC were tested for tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), and interferon-gamma (IFN-gamma) by specific ELISA, after stimulation with phytohemagglutinin (PHA) or lipopolysaccharide (LPS) in the presence or absence of different concentrations of chloroquine or hydroxychloroquine. RESULTS: We observed that chloroquine and hydroxychloroquine equally inhibit PHA induced TNF-alpha and IFN-gamma production, and LPS induced TNF-alpha and IL-6 production, while PHA induced IL-6 production was not affected. CONCLUSION: Chloroquine and hydroxychloroquine display similar effects on PHA and LPS induced cytokine production by PBMC under identical in vitro conditions. These findings may help in understanding the mechanism of action of these drugs on RA.

Adult↗
PubMed1994

Pharmacokinetics and pharmacodynamics of hydroxychloroquine enantiomers in patients with rheumatoid arthritis receiving multiple doses of racemate.

Hydroxychloroquine, a slow acting antirheumatic drug, is administered as the racemic mixture. Blood concentrations of the two enantiomers of hydroxychloroquine were measured in two studies, one study of eight patients, in whom blood and urine concentrations were measured during the first 6 months of therapy with rac-hydroxychloroquine, and one of 43 patients who had received rac-hydroxychloroquine therapy for at least 6 months. In the latter study rheumatoid disease activity was also measured. The pharmacokinetics of hydroxychloroquine were found to be enantioselective. The concentrations of (-)-(R)-hydroxychloroquine were higher than those of the (+)-(S)-antipode in all patients at all time points, although the ratios of the two enantiomers did display a two to three fold variability between patients. Both total and renal clearance were greater for the (+)-(S)-enantiomer. From the observational, cross-sectional study design used, it was not possible to differentiate concentration-effect relationships of the two enantiomers. The 11-fold range of drug concentrations swamped any effect of variability between patients in enantiomer proportions. Blood concentrations of both enantiomers were significantly higher in groups of patients with less active disease.

Arthritis, Rheumatoid↗
PubMed2001

Effect of hydroxychloroquine on progression of dementia in early Alzheimer's disease: an 18-month randomised, double-blind, placebo-controlled study.

BACKGROUND: Results of epidemiological studies, neuropathological observations, and in-vitro experiments all suggest that inflammatory mechanisms contribute to the destructive lesions in Alzheimer's disease. We aimed to establish the effect of the anti-inflammatory drug hydroxychloroquine on the progression of dementia. METHODS: We did a double-blind, parallel-group, multicentre trial in which we randomly assigned 168 patients with early Alzheimer's disease to hydroxychloroquine (200 or 400 mg dependent on bodyweight), or placebo for 18 months. Outcome measures were related to activities of daily living, cognitive function, and behavioural abnormalities. Analysis was by intention to treat. RESULTS: At 18 months, mean scores for the interview for deterioration in daily life in dementia in patients on hydroxychloroquine (22.6 [SD 11.4]) did not differ from those for patients on placebo (21.3 [10.5]). Also, mean scores on the cognitive subscale of the Alzheimer's disease assessment scale were closely similar in hydroxychloroquine (26.4 [14.9]) and placebo (25.7 [14.3]) treated patients, as were behavioural changes, measured by the revised memory and behavioural problems checklist (36.3 [12.0] and 34.2 [12.4], respectively). Explorative analyses did not suggest any specific subgroup that benefited from hydroxychloroquine. The frequency and nature of serious adverse events and side-effects were much the same in both groups. 155 (92%) patients completed all assessments over the entire study. INTERPRETATION: Anti-inflammatory treatment with hydroxychloroquine for 18 months does not slow the rate of decline in minimal or mild Alzheimer's disease.

Activities of Daily Living↗
PubMed1989

Bioavailability of hydroxychloroquine tablets in healthy volunteers.

1. Five healthy volunteers received, in a randomised crossover design study, a 155 mg oral tablet and an intravenous infusion of 155 mg racemic hydroxychloroquine (200 mg hydroxychloroquine sulphate) to assess the bioavailability of the commercially available tablet (Plaquenil, Winthrop Laboratories, Australia). 2. The terminal elimination half-life of hydroxychloroquine is more than 40 days, thus blood and urine samples were collected for 5 months following each dose to characterise adequately the terminal elimination phase and obtain accurate estimates of the areas under the concentration-time curves. 3. The mean (+/- s.d.) fraction of the oral dose absorbed, estimated from the blood and urine data, was 0.74 (+/- 0.13). A wide range of estimates of the fraction of the oral dose absorbed was calculated from the plasma data (0.41 - 1.53), reflecting the difficulties of accurate measurement of hydroxychloroquine in plasma. 4. A period of 6 months is required to achieve 96% of steady-state levels of hydroxychloroquine with the usual once daily, oral dosage regimen. Pharmacokinetic factors may thus be partly responsible for the delayed action of the drug in rheumatic conditions. 5. Haemodialysis will not aid in the case of oral overdose with hydroxychloroquine. Although the proportionate increase in clearance may be large, the increase in the fraction of the dose excreted will be negligible. The extensive sequestration of the drug by tissues limits effectiveness of haemodialysis.

Biological Availability↗
PubMed1983

Hydroxychloroquine versus phlebotomy in the treatment of porphyria cutanea tarda.

Hydroxychloroquine and phlebotomy were compared in the treatment of porphyria cutanea tarda (PCT). Thirty patients received hydroxychloroquine (200 mg twice weekly) for 1 year and thirty-one underwent twice-monthly phlebotomies of 400 ml whole blood each, also for 1 year. Clinical signs of disease improved equally in both groups. At the end of the year, urinary porphyrin excretion had significantly improved in twenty-two out of thirty hydroxychloroquine-treated subjects, but in only eight out of the thirty-one patients who received phlebotomy. Liver histology showed significant regression of steatosis and siderosis in both groups compared with the pretrial biopsy, but the activity of liver disease, as judged by the extent of necrosis, inflammation and fibrosis, worsened in twelve hydroxychloroquine and in seven phlebotomy-treated patients. It is concluded that hydroxychloroquine is more effective than phlebotomy in decreasing porphyrin production. However, further work is needed to assess whether long-term hydroxychloroquine treatment favours the progression of the chronic liver disease associated with PCT.

Adult↗
PubMed1993

Hydroxychloroquine treatment for primary Sjögren's syndrome: a two year double blind crossover trial.

OBJECTIVES: In 1985 and 1988 a positive effect of treatment of primary Sjögren's syndrome with hydroxychloroquine was reported in two small open studies. To investigate further the clinical and laboratory effects of hydroxychloroquine in primary Sjögren's syndrome a two year study was performed. METHODS: The design of the study included a prospective, placebo controlled, two year double blind crossover trial in 19 patients. RESULTS: A significant decrease in IgG and IgM and a tendency for a decrease in the erythrocyte sedimentation rate (ESR) during treatment with hydroxychloroquine compared with treatment with placebo were found. No beneficial clinical effect of the use of hydroxychloroquine as expressed in preference for treatment with hydroxychloroquine or placebo with regard to symptoms and signs of primary Sjögren's syndrome could be shown, however, nor any relevant change in tear gland activity and sequelae of peripheral tear function deficiency, nor salivary gland scintigraphy. CONCLUSIONS: The use of hydroxychloroquine at a dose of 400 mg daily taken over a 12 month period does not have a worthwhile clinical benefit in patients with primary Sjögren's syndrome despite an improvement of hyperglobulinaemia and slight changes in the ESR and IgM.

Adult↗
PubMed1999

Hydroxychloroquine treatment for primary Sjögren's syndrome: its effect on salivary and serum inflammatory markers.

OBJECTIVE: To evaluate the effect of hydroxychloroquine treatment on interleukin 6 (IL6), hyaluronic acid (HA), and soluble interleukin 2 receptor (sIL2R) concentrations in the saliva and serum of patients with primary Sjögren's syndrome (SS). METHODS: Fourteen SS patients treated with hydroxychloroquine 200 mg/day for 12 months were investigated in an open prospective study. Clinical parameters of efficacy and routine biochemical and haematological data to assess drug safety and tolerability were determined every three months. Salivary and serum IL6, sIL2R, and HA values were determined at study entry, 6 and 12 months, using ELISA and radiometric assays. RESULTS: After hydroxychloroquine treatment, salivary IL6 concentrations decreased from 13.2 (1.2) to 7.3 (1.1) pg/ml (mean (SEM)) (p < 0.0001). Similarly, salivary HA concentrations were also reduced from 577.8 (120) to 200 (34) ng/ml (mean (SEM) (p < 0.003). Serum IL6 concentrations decreased from 5.4 (0.6) to 2.9 (0.2) pg/ml (mean (SEM) (p < 0.001), while serum HA concentrations remained unchanged. No change has been detected in salivary or serum sIL2R concentrations after 12 months of treatment with hydroxychloroquine. Treatment also resulted in significant reduction in erythrocyte sedimentation rate, serum gamma globulin, and C reactive protein values while only partial clinical improvement was noted in some patients. A more pronounced decrease of salivary IL6 and HA levels was found in the two patients in whom a reduction in the swelling of the parotid gland was noted. CONCLUSION: In this open label study of hydroxychloroquine treatment for SS a significant reduction of some salivary inflammatory markers was seen at the end of 12 months. Although during the treatment period only a partial clinical effect could be noted, the findings suggest that a double blind controlled study of hydroxychloroquine in SS is indicated.

Antirheumatic Agents↗
PubMed2000

Concentration-effect relationship of hydroxychloroquine in patients with rheumatoid arthritis--a prospective, dose ranging study.

OBJECTIVE: A 6 month prospective randomized double blind study was conducted to investigate hydroxychloroquine dose concentration-effect relationships in people with rheumatoid arthritis. METHODS: Patients were randomized in 2 groups: one group received 200 mg hydroxychloroquine sulfate daily (A) and one group received 400 mg daily (B). Each month, 8 disease variables were assessed, adverse events recorded, and hydroxychloroquine blood concentrations determined. RESULTS: Twenty-three patients were included: 10 in group A and 13 in group B. After 6 months of therapy, a significant improvement in disease activity was noted for 6 criteria with no statistical differences between groups: pain (assessed by a visual analog scale), joint scores (swelling and tenderness), impairment in daily living activity (18 activities graded 0 to 8), patient assessment of disease state, and erythrocyte sedimentation rate. Hydroxychloroquine steady-state blood concentrations (Month 6) were significantly different between groups (mean +/- SD): 450.6 +/- 285.3 ng/ml (A) vs 870.3 +/- 329.3 ng/ml (B) (p = 0.0001). Steady-state concentrations were correlated with the daily dose (r = 0.63, p = 0.005), the improvement in activity of daily living (r = 0.49, p = 0.03), and the improvement in joint tenderness score (r = 0.47, p = 0.038). CONCLUSION: The data indicate that hydroxychloroquine is an effective therapy, but there were no further improvements observed in the group receiving 400 mg daily compared to those receiving 200 mg. There were some correlations between hydroxychloroquine steady-state blood concentrations and effects.

Adult↗
PubMed1984

A comparative trial of desferrioxamine and hydroxychloroquine for treatment of porphyria cutanea tarda in alcoholic patients.

Forty male alcoholic patients with porphyria cutanea tarda (PCT) were randomly assigned to 2 groups of 20. The 1st group received desferrioxamine (30 mg/kg body weight/day for 1 week every 3 months) whereas the latter was given hydroxychloroquine (200 mg twice/wk orally). Alcohol abstinence was advised for all patients. Improvement of cutaneous signs was evident after 6 months in hydroxychloroquine-treated subjects and after 12 months in desferrioxamine-treated subjects. At the end of the 1-year clinical trial, significant decreases of serum iron and ferritin were found in all patients, irrespective of the therapy. Urinary total porphyrins were reduced significantly in both groups, but the drop was significantly more evident in hydroxychloroquine- than in desferrioxamine-treated subjects. After 1 year of therapy, 4 desferrioxamine-treated patients vs 16 hydroxychloroquine-treated subjects acquired a normal urinary porphyrin pattern. These results indicate that hydroxychloroquine is more effective than desferrioxamine in inducing clinical and biochemical remission of PCT. Accordingly, hydroxychloroquine should be the preferred alternative to phlebotomy, if the latter is contraindicated.

Adult↗
PubMed1993

Concentration-effect relationship of hydroxychloroquine in rheumatoid arthritis--a cross sectional study.

OBJECTIVE: To determine the relationship between hydroxychloroquine concentration and effect in patients with rheumatoid arthritis (RA). METHODS: Using a cross sectional study design, drug concentration and effect were measured at one time. Forty-three patients with RA, receiving hydroxychloroquine therapy for at least 6 months and not receiving glucocorticosteroids, gold or penicillamine therapy were enrolled. The main outcome measures were hydroxychloroquine concentration and disease activity measured as degree of synovitis, pain, duration and intensity of morning stiffness, impairment of activities of daily living, patients' and physicians' subjective assessment of disease, erythrocyte sedimentation rate, and rheumatoid factor (RF). Hemoglobin and albumin concentrations were also recorded. RESULTS: Patients with none or mild intensity of morning stiffness, those with stiffness lasting less than 0.5 h and those with negative RF had significantly higher hydroxychloroquine blood concentrations than those in whom these measures indicated a more active disease (Mann-Whitney U test, p < 0.05). Similar trends were recorded for 3 other disease activity measures (p = 0.12-0.24). Analysis of all 9 individual disease activity measures indicated that the groups with less active disease had higher mean blood concentrations of hydroxychloroquine than those with measures indicating more active disease (p < 0.01). CONCLUSION: Our data provide the first evidence of a concentration-response relationship for hydroxychloroquine in RA for individual disease activity measures. However, an unweighted summed score of disease activity did not correlate significantly with drug blood concentrations. A prospective study is necessary to confirm the relationship and to determine a therapeutic concentration range.

Adult↗
PubMed1991

A randomized study of the effect of withdrawing hydroxychloroquine sulfate in systemic lupus erythematosus.

BACKGROUND: The antimalarial drug hydroxychloroquine is thought to be effective in controlling some of the manifestations of systemic lupus erythematosus, but its effectiveness has not been demonstrated conclusively. METHODS: We conducted a six-month, randomized, double-blind, placebo-controlled study of the effect of discontinuing hydroxychloroquine sulfate treatment in 47 patients with clinically stable systemic lupus erythematosus. The patients were randomly assigned to continue their same dose of hydroxychloroquine (n = 25) or to receive placebo (n = 22) for 24 weeks. Ten patients in each group were also taking prednisone. RESULTS: The relative risk of a clinical flare-up, defined as the development of specific clinical manifestations of systemic lupus erythematosus or an increase in their severity, was 2.5 times higher (95 percent confidence interval, 1.08 to 5.58) in the patients taking placebo than in those continuing to take hydroxychloroquine (16 of 22 patients vs. 9 of 25 had flare-ups), and the time to a flare-up was shorter (P = 0.02). The relative risk of a severe exacerbation of disease that required withdrawal from the study was 6.1 times higher (95 percent confidence interval, 0.72 to 52.44) for the patients taking placebo (5 of 22 patients vs. 1 of 25 had severe exacerbations of disease). Changes in the dose of prednisone were not different in the two groups. CONCLUSIONS: Patients with quiescent systemic lupus erythematosus who are taking hydroxychloroquine are less likely to have a clinical flare-up if they are maintained on the drug.

Adult↗
PubMed1998

Effectiveness of chloroquine and hydroxychloroquine in treating selected patients with sarcoidosis with neurological involvement.

OBJECTIVE: To assess the efficacy of chloroquine (Aralen) phosphate and hydroxychloroquine (Plaquenil) sulfate in the treatment of patients with neurosarcoidosis who either do not respond to corticosteroid therapy or develop unacceptable side effects. DESIGN: Retrospective study. SETTING: Sarcoidosis clinic at a university teaching hospital. PATIENTS: Twelve patients with biopsy-proved sarcoidosis, 6 women and 6 men ranging from 20 to 49 years of age, with neurological involvement. INTERVENTION: Chloroquine phosphate, 250 mg twice daily, or hydroxychloroquine sulfate, 200 mg twice daily, was administered for a period of 6 to 21 months. Patients had regular clinical evaluation, determination of serum and cerebrospinal fluid angiotensin-converting enzyme level, computed tomography or magnetic resonance imaging, chest radiography, lung function testing, and slit-lamp examination of the eyes. RESULTS: Chloroquine or hydroxychloroquine either stabilized symptoms or controlled neurological symptoms in 10 of 12 patients. Two patients failed to respond. Cerebrospinal fluid abnormalities, including lymphocytosis, were seen in 3 patients. Magnetic resonance imaging with gadolinium was most helpful in supporting the diagnosis of sarcoidosis and monitoring the course of the disease. CONCLUSIONS: Chloroquine and hydroxychloroquine are effective in controlling neurological sarcoidosis in those patients who fail to respond to corticosteroids or develop severe side effects. Ocular toxic effects from chloroquine or hydroxychloroquine were not observed.

Adult↗
PubMed1992

Bioavailability of hydroxychloroquine tablets assessed with deconvolution techniques.

Four deconvolution methods (staircase, delta function, and least squares methods using single and sequential first-order input functions) were used to assess the absolute bioavailability of hydroxychloroquine tablets in nine healthy fasting volunteers. The volunteers received, in a random crossover design, a 155-mg oral tablet and a 155-mg iv infusion of racemic hydroxychloroquine. The mean fractions of the dose absorbed, calculated using the four deconvolution methods, were not statistically different (p = 0.70). The mean fraction absorbed (+/- SD) was 0.67 +/- 0.12, which was not significantly different from that reported previously in a conventional bioavailability study (p = 0.22). The mean absorption half-life was calculated to be 4.0 +/- 1.3 h. The mean lag time before absorption commenced was 0.57 +/- 0.30 h. The fraction of the dose absorbed ranged from 0.44 to 0.86. Low and/or variable bioavailability of hydroxychloroquine may be a cause of therapeutic failure in some patients. Validation of the deconvolution methods means that these techniques may now be used to assess the bioavailability of hydroxychloroquine in patients. An advantage of these methods is that samples need only be collected over the expected time period of absorption, rather than the whole time drug can be detected in the body, as is required in conventional area under the concentration-time curve ratio methods. Deconvolution studies may be completed in 2 weeks rather than the 10 months required for a conventional bioavailability study of hydroxychloroquine.

Adult↗