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Chlorproguanil-dapsone for treatment of drug-resistant falciparum malaria in Tanzania.

BACKGROUND: Resistance to the affordable malaria treatments chloroquine and pyrimethamine-sulfadoxine is seriously impeding malaria control through treatment in east Africa. We did an open, alternate drug allocation study to assess the efficacy of chlorproguanil-dapsone in the treatment of falciparum malaria clinically resistant to pyrimethamine-sulfadoxine. METHODS: Children younger than 5 years with non-severe falciparum malaria, attending Muheza district hospital in Tanzania, were treated with the standard regimen of pyrimethamine-sulfadoxine. Patients whose clinical symptoms resolved but who remained parasitaemic 7 days after pyrimethamine-sulfadoxine were followed up for 1 month. Clinical malaria episodes were retreated with either single dose pyrimethamine-sulfadoxine or a 3-day regimen of chlorproguanil-dapsone. Those with parasitaemia after 7 days were treated with chlorproguanil-dapsone. Parasite DNA was collected on day 7 after first treatment with pyrimethamine-sulfadoxine and we looked for point mutations in the genes encoding dihydrofolate reductase (dhfr) and dyhydropteroate synthetase (dhps). FINDINGS: 360 children were enrolled and treated with pyrimethamine-sulfadoxine. On day 7, 192 (55%) of 348 had cleared parasitaemia. Of the remaining 156 parasitaemic children, 140 (90%) were followed up to day 28, and 92 (66%) of 140 developed clinical malaria. These 92 patients were alternately retreated with either pyrimethamine-sulfadoxine (46) or chlorproguanil-dapsone (46). 28 (61%) of 46 children retreated with pyrimethamine-sulfadoxine were still parasitaemic at day 7, compared with three (7%) of 44 [corrected] children retreated with chlorproguanil-dapsone. Resistance to pyrimethamine-sulfadoxine increased from 45% (156/348) at the first treatment to 61% (28/46) after retreatment. 83 of 85 parasite isolates collected after the first pyrimethamine-sulfadoxine treatment, and before and after the second treatments with pyrimethamine-sulfadoxine and chlorproguanil-dapsone showed triple-mutant dhfr alleles, associated with a variety of dhps mutations. INTERPRETATION: Most patients treated with pyrimethamine-sulfadoxine, who remain parasitaemic at day 7, develop new malaria symptoms within 1 month. Chlorproguanil-dapsone was a practicable therapy under these circumstances. Analysis of parasite dhfr and dhps before and after treatment supports the view that pyrimethamine-sulfadoxine resistance in this part of Africa is primarily due to parasites with three mutations in the dhfr domain.

Adolescent↗

Chlorproguanil-dapsone versus sulfadoxine-pyrimethamine for sequential episodes of uncomplicated falciparum malaria in Kenya and Malawi: a randomised clinical trial.

BACKGROUND: Chlorproguanil-dapsone exerts lower resistance pressure on Plasmodium falciparum than does sulfadoxine-pyrimethamine, but is rapidly eliminated. We aimed to find out whether chlorproguanil-dapsone results in a higher retreatment rate for malaria than sulfadoxine-pyrimethamine. METHODS: In a randomised trial of paediatric outpatients with uncomplicated falciparum malaria, patients received either chlorproguanil-dapsone or sulfadoxine-pyrimethamine and were followed up for up to 1 year. Sites were in Kenya (n=410) and Malawi (n=500). We used per-protocol analysis to assess the primary outcome of annual malaria incidence. FINDINGS: Drop-outs were 117 of 410 (28.5%) in Kenya, and 342 of 500 (68.4%) in Malawi. Follow-up was for a median of 338 days (IQR 128-360) and 342 days (152-359) in Kilifi (chlorproguanil-dapsone and sulfadoxine-pyrimethamine, respectively), and for 120 days (33-281) and 84 days (26-224) in Blantyre. Mean annual malaria incidence was 2.5 versus 2.1 in Kenya (relative risk 1.16, 95% CI 0.98-1.37), and 2.2 versus 2.8 in Malawi (0.77, 0.63-0.94). 4.3% versus 12.8%, and 5.4% versus 20.1%, of patients were withdrawn for treatment failure in Kenya and Malawi, respectively. In Kenya haemoglobin concentration of 50 g/L or less caused exit in 6.9% of chlorproguanil-dapsone patients and 1.5% of sulfadoxine-pyrimethamine patients, but most anaemia occurred before re-treatment. In Malawi only one patient exited because of anaemia. INTERPRETATION: Despite the rapid elimination of chlorproguanil-dapsone, children treated with this drug did not have a higher incidence of malaria episodes than those treated with sulfadoxine-pyrimethamine. Treatment failure was more common with sulfadoxine-pyrimethamine. Cause of anaemia in Kenya was probably not adverse reaction to chlorproguanil-dapsone, but this observation requires further study.

Antimalarials↗

[Dapsone treatment of folliculitis decalvans].

BACKGROUND: Folliculitis decalvans consists of recurrent patchy painful folliculitis of the scalp causing scarring alopecia. The physiopathology of this condition is still unclear, but is likely a manifestation of chronic neutrophilic bacterial folliculitis. Numerous topical and systemic treatments (corticosteroids, antistaphylococcal antibiotics) have been used with variable results. Based on the dapsone antimicrobial activity and its anti-inflammatory action especially directed to the neutrophil metabolism, we treated two patients with severe folliculitis decalvans with this drug. CASE REPORTS: The patients were treated with dapsone at a daily dose of 75 and 100 mg, respectively for 4 to 6 months. After 1 and 2 months, pustular folliculitis progressively cleared, leaving a residual non inflammatory cicatricial alopecia. When maintaining a dapsone dosage at 25 mg/day no relapse occurred during 3 years and 1 year, respectively. No important adverse effect to dapsone was evidenced. After dapsone withdrawal, a moderate relapse of the disease with pruritus and folliculitis occurred after a few weeks in both cases. The disease relapse rapidly cleared after dapsone reintroduction at a daily dose of 25 mg. COMMENTS: Dapsone at moderate dosage was well tolerated and rapidly effective in treating the two cases of folliculitis decalvans. A long term and low dose (25 mg daily) maintenance treatment avoided disease relapses.

Adult↗

Oral activated charcoal and dapsone elimination.

The effect of orally given activated charcoal on the elimination of therapeutic and toxic doses of dapsone was studied in 5 healthy subjects and in 2 intoxicated patients. In a randomized crossover study the subjects took a total dose of 500 mg dapsone over 4 days; 10 hr after the last 100-mg dose of dapsone 50 gm activated charcoal as a water suspension (or water) was taken, followed by 4 consecutive doses of 17 gm at 12-hr intervals. The half-life (t 1/2) of serum dapsone was 20.5 +/- 2.0 hr during the control period and 10.8 +/- 0.4 hr during the charcoal period (p less than 0.01). The t 1/2 on serum monoacetyldapsone (MADDS) was shortened from 19.3 +/- 1.2 hr to 9.5 +/- 0.7 hr (p less than 0.01) by charcoal. The t 1/2s of dapsone and MADDS, calculated on the basis of urinary excretion rate, were shortened by charcoal; Two patients had taken large doses of dapsone in suicide attempts. The use of activated charcoal, 80 gm/day for 1 or 2 days, increased (3 to 5 times) the rate of elimination of both dapsone and MADDS, as reflected in serum concentration and urinary excretion data. The use of multiple doses of charcoal seems to be indicated as supplementary treatment of certain intoxications during the postabsorption phase if the drugs have a long t 1/2 and if they are secreted into the gut with subsequent reabsorption.

Absorption↗

Frequency distribution of dapsone N-hydroxylase, a putative probe for P4503A4 activity, in a white population.

Phenotypic trait values in 166 healthy white subjects (age range, 18 to 88 years) were determined for dapsone N-hydroxylation, dapsone N-acetylation, debrisoquin 4-hydroxylation, and S-mephenytoin 4'-hydroxylation after single oral dose administration of the probe drugs dapsone (100 mg), debrisoquin (10 mg), and mephenytoin (100 mg). No associations or evidence of cosegregation were found between the individual routes of metabolism. Dapsone N-hydroxylation exhibited a unimodal distribution, with marked (tenfold) intersubject variability, and aging was associated with reduced N-oxidation. However, the other measured routes of metabolism were age independent, but intersubject variability in all of the trait measurements increased with age. In subjects younger than 50 years, S-mephenytoin 4'-hydroxylation was modestly (34%) less in men than in women. In contrast, dapsone N-acetylation, dapsone N-hydroxylation, and debrisoquin 4-hydroxylation were not influenced by gender. Previous smoking habit and alcohol consumption were not associated with a difference in any of the four routes of metabolism. Accordingly, the measured phenotypic traits of drug oxidation and N-acetylation appear to be quite robust in regard to some common demographic variabilities present in population studies, with the exception of dapsone N-hydroxylase, which is affected by aging.

Acetylation↗

Penetration of dapsone into cerebrospinal fluid of patients with AIDS.

It has been proposed that dapsone in combination with pyrimethamine could be used for prophylaxis of both Pneumocystis carinii pneumonia and encephalitis due to Toxoplasma gondii. Ten patients with AIDS undergoing lumbar puncture for diagnostic purposes were studied in order to assess the penetration of dapsone into CSF. Blood and CSF samples were obtained between 3 and 72 h following administration. Six patients had received oral dapsone for at least 1 month at the dosage regimen of 100 mg twice of three times weekly and four patients had received a single oral 100 mg dose. Dapsone concentration in CSF ranged from 0.013 to 0.296 mg/L while concentrations in plasma ranged from 0.018 to 1.231 mg/L. The CSF:plasma concentration ratio ranged from 0.21 to 2.01. The MIC of dapsone in combination with pyrimethamine against T. gondii is unknown, and further data are required to confirm whether the CSF concentrations of dapsone found in our study are sufficient to inhibit T. gondii growth in patients infected with human immunodeficiency virus (HIV). The high interpatient variability of dapsone CSF concentrations warrants further studies in selected categories of patients with HIV infection.

Acquired Immunodeficiency Syndrome↗

N-Hydroxylation of dapsone by multiple enzymes of cytochrome P450: implications for inhibition of haemotoxicity.

1. The adverse reactions associated with the administration of dapsone are believed to be caused by metabolism to its hydroxylamine. Previous reports suggest that CYP3A4 is responsible for this biotransformation [1]. 2. Data presented in this paper illustrate the involvement of more than one cytochrome P450 enzyme in dapsone hydroxylamine formation using human liver microsomes. Eadie-Hofstee plots demonstrated bi-phasic kinetics in several livers. No correlation could be established between hydroxylamine formation and CYP3A concentrations in six human livers (r = -0.47; P = 0.34). 3. Studies with low molecular weight inhibitors illustrate the importance of CYP2C9 and CYP3A in dapsone N-hydroxylation. 4. Differential sensitivity of dapsone N-hydroxylation to selective CYP inhibitors indicated that the contribution of individual CYP enzymes varies between livers. Selective inhibition ranged from 6.8 to 44.1% by 5 microM ketoconazole, and from 24.0 to 68.4% by 100 microM sulphaphenazole. The extent of inhibition, by either ketoconazole or sulphaphenazole was dependent on the CYP3A content of the liver. 5. The levels of expression of these cytochrome P450 enzymes may be an important determinant of individual susceptibility to the toxic effects of dapsone, and may influence the ability of an enzyme inhibitor to block dapsone toxicity in vivo. Because of the inability to produce complete inhibition, selective CYP inhibitors are unlikely to offer any clinical advantage over cimetidine in decreasing dapsone hydroxylamine formation in vivo.

Anti-Infective Agents↗

Comparison of hyperbaric oxygen and dapsone therapy for loxosceles envenomation.

OBJECTIVE: To determine whether hyperbaric O2 (HBO), dapsone, or HBO plus dapsone affects lesion size in a swine model of Loxosceles envenomation. METHODS: In a randomized controlled animal laboratory experiment, 32 piglets were assigned to 1 of 4 equal groups. Each piglet received 15 microliters, of purified venom intradermally on day zero. Group 1 received no treatment; group 2 received HBO at 2 atm for 2 hours on days 1-3; group 3 received 50 mg of dapsone orally on days 1-3; and group 4 received dapsone 50 mg orally and HBO at 2 atm for 2 hours on days 1-3. On days 1-7, 14, and 21, an investigator blinded to the treatment groups measured necrosis and induration. Mean necrosis and induration rates were compared using analysis of variance for repeated measures. RESULTS: Comparing groups on any day, no significant difference was noted in necrosis, induration, reduction in necrosis from day 1, or rate of change in lesion size from days 1-7. A difference was seen in the reduction of induration between all 3 treatment groups and the control group on days 7 and 14 only. The sample size permitted a power of 0.8 to detect a 12-mm mean change in lesion size. CONCLUSION: Compared with the control, neither dapsone, HBO, nor the combination of dapsone and HBO reduced necrosis from Loxosceles envenomation on days 3-21. An increase was seen in the rate of reduction in induration between all 3 treatment groups and the control group on days 7-21. However, the magnitude of this effect was clinically insignificant. In this animal model, treatment with either dapsone or HBO or a combination offers little clinical benefit in Loxosceles envenomation.

Animals↗

Dapsone treatment of Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome.

All patients with the acquired immunodeficiency syndrome treated for their first episode of Pneumocystis carinii pneumonia at San Francisco General Hospital between 1 April 1985 and 15 July 1985 were evaluated for their response to treatment with dapsone (100 mg/day) by mouth for 21 days. Of 44 patients evaluated, 18 were eligible for the study. Of these 18 patients, the conditions of 7 of them worsened or failed to improve during treatment with dapsone and they were considered treatment failures. These patients were changed to standard therapy after 4 to 8 days of dapsone therapy. The remaining 11 patients (61%) improved within 3 to 10 days after dapsone therapy was started. Side effects of dapsone therapy were noted in 6 of 11 patients (of these 11 patients, 5 had a rash, 1 had a rash and abnormal liver enzymes, and 1 had abnormal liver enzymes), but in none of the patients were these side effects severe enough to require the cessation of medication. Based on comparison with historical controls, oral dapsone therapy alone appeared to be less effective than standard therapy or the combination of dapsone plus trimethoprim for P. carinii pneumonia in patients with acquired immunodeficiency syndrome.

Acquired Immunodeficiency Syndrome↗

Clarithromycin, dapsone, and a combination of both used to treat or prevent disseminated Mycobacterium avium infection in beige mice.

Bacteremic infection caused by organisms of the Mycobacterium avium complex (MAC) is common in patients with AIDS. We evaluated both clarithromycin and dapsone alone and in combination for the treatment and prevention of disseminated MAC disease in beige mice. In the therapeutic model, C57BL/6 beige mice were infected intravenously with strain 101 of MAC (serovar 1). After 1 week postinfection, mice were given clarithromycin (200 mg/kg of body weight per day) and dapsone (15 mg/kg of body weight per day) alone or in combination by gavage. Treatment with clarithromycin resulted in a significant reduction in bacteremia and the numbers of CFU of MAC in the liver and spleen. Treatment with dapsone had no effect on the mycobacterial counts in blood, liver, or spleen, and the combination of dapsone with clarithromycin was no better than clarithromycin as a single agent. Clarithromycin and dapsone were used to prevent systemic disease in beige mice infected orally with MAC 101. Clarithromycin prophylaxis was associated with a significant reduction in the numbers of bacteria in the liver, spleen, and appendix compared with those in controls. Prophylaxis with dapsone resulted in a mild reduction in the numbers of MAC in the spleen but not in the other tissues. Clarithromycin both treats and prevents MAC disease in beige mice. Dapsone has no therapeutic effect, but it does have a slight prophylactic effect, and in combination with clarithromycin it does not abrogate the effect of clarithromycin.

Animals↗

Evaluation of effects of altered gastric pH on absorption of dapsone in healthy volunteers.

A prospective, randomized, crossover study was performed with seven healthy volunteers to address the effect of increased gastric pH on dapsone absorption. Subjects were randomized to receive a single 100-mg dose of dapsone or a single 100-mg dose of dapsone in addition to 30 ml of a high potency antacid 1 h before dapsone administration and hourly thereafter for a total of 10 doses. Dapsone concentrations in serum were measured periodically for 48 h. No statistical differences between the two regimens were noted when mean dapsone maximal initial concentrations, times to peak, and areas under the curve were compared. These data suggest that an increase in gastric pH has little or no effect on the absorption of dapsone in healthy subjects.

Adult↗

Pharmacokinetics of dapsone in human immunodeficiency virus-infected children.

Dapsone, administered at various doses and schedules, has been proven to be a safe and effective alternative to trimethoprim-sulfamethoxazole for prevention of Pneumocystis carinii pneumonia (PCP) in adults with human immunodeficiency virus (HIV) infection. Dapsone is also recommended by the Centers for Disease Control for PCP prophylaxis in HIV-infected children. However, the suggested dosage regimen is based upon clinical experience with children with leprosy and dermatitis herpetiformis rather than pharmacokinetic and pharmacodynamic data obtained from the target patient population. In order to determine a rational dosage regimen that could be tested in clinical studies aimed at the evaluation of dapsone for the prevention of PCP in HIV-infected children, we studied the pharmacokinetics of dapsone following a 2-mg/kg of body weight oral dose in twelve HIV-positive children aged 9 months to 9 years. Plasma was collected at the following times after dapsone administration: 0, 2, 4, 6, 12, 24, 48, 72, and 96 h. The levels of dapsone in plasma were determined by high-performance liquid chromatography. Data were analyzed by noncompartmental methods. Expressed as means +/- standard deviations (ranges), the pharmacokinetic parameters were as follows: peak concentration in plasma, 1.12 +/- 0.48 (0.44 to 1.81) mg/liter; time to peak concentration in plasma, 3.8 +/- 1.3 (2 to 6) h; half-life at elimination phase, 24.2 +/- 7.1 (14.4 to 35.0) h; clearance from plasma divided by bioavailability (CL/F), 1.15 +/- 0.67 (0.37 to 2.63) ml/min/kg; and volume of distribution divided by bioavailability (V/F), 2.25 +/- 1.20 (1.00 to 4.57) liters/kg. Oral CL correlated negatively with age (r = 0.614 and P = 0.034), as did V (r = 0.631 and P = 0.028). As a consequence of the high interindividual variability in growth retardation, pharmacokinetic parameters correlated with measures of body development better than they did with age (e.g., for CL/F to height, r = 0.765 and P = 0.004, and for V/F to height, r = 0.748 and P = 0.005). Since oral CL from plasma and V were positively and highly correlated (r = 0.898 and P = 0.0001), a lower absolute F may be the cause, in part, of higher values for CL/F and V/F in smaller children. The results of this study warrant the testing of a 2-mg/kg dose of dapsone administered twice or thrice weekly to HIV-infected children. The monitoring of drug levels in plasma and dosage adjustment may be necessary for smaller children.

Aging↗

Zidovudine, trimethoprim, and dapsone pharmacokinetic interactions in patients with human immunodeficiency virus infection.

Zidovudine is widely prescribed for the treatment of human immunodeficiency virus (HIV) infection. Trimethoprim and dapsone are commonly used in the management of Pneumocystis carinii pneumonia in HIV-infected patients. To examine the pharmacokinetic interactions among these drugs, eight HIV-infected patients (26 to 43 years old) with a mean CD4 count of 524.4 +/- 405.7 cells per mm3 received zidovudine (200 mg), trimethoprim (200 mg), and dapsone (100 mg) as single agents and in two- and three-drug combinations. Blood and urine samples were collected at a specified time and analyzed for zidovudine, zidovudine-glucuronide, trimethoprim, dapsone, and monoacetyl-dapsone concentrations under single-dose and steady-state conditions. Zidovudine did not influence the pharmacokinetic disposition of dapsone or trimethoprim. Dapsone had no effect on the pharmacokinetic disposition of zidovudine. Trimethoprim significantly decreased the renal clearance of zidovudine by 58% (5.0 +/- 1.8 versus 2.1 +/- 0.5 ml/min/kg of body weight [P < 0.05]). There was a concurrent 54% decrease in the mean urinary recovery of zidovudine (11.7 +/- 3.5 versus 5.4 +/- 3.0 [P < 0.05]), and the metabolic ratio was decreased by 78% (0.32 +/- 0.4 versus 0.07 +/- 0.05 [P < 0.05]). The mean area under the concentration-time curve from 0 to 6 h of the zidovudine-glucuronide/ zidovudine ratio was unchanged. We conclude that zidovudine, trimethoprim, and dapsone can be coadministered to patients with AIDS without significant pharmacokinetic interaction. However, in AIDS patients with liver impairment and impaired glucuronidation, doses of zidovudine may need to be decreased.

Acquired Immunodeficiency Syndrome↗

Dapsone inhibits the generation of 5-lipoxygenase products in human polymorphonuclear leukocytes.

Dapsone (4,4'-diaminodiphenylsulfone) is effective in treating inflammatory skin diseases. Several lines of evidence suggest that the anti-inflammatory properties of this sulfone are partially due to modulation of functions of polymorphonuclear leukocytes (PMN). The goal of the present investigation is therefore to ascertain possible inhibitory effects of dapsone upon human 5-lipoxygenase (5-LOX) pathway. PMN of healthy donors were pretreated with dapsone in different concentrations (1.6-100 microM) for 5 min following by adding Ca ionophore A 23187 (10 microM) and subsequent incubation for 10 min. Thereupon the eicosanoids were assessed by reversed-phase high-performance liquid chromatography (RP-HPLC). Dapsone exhibited dose-dependent inhibitory activity showing 50% inhibition at 15 microM for leukotriene B4 (LTB4) with 5 x 10(6) PMN. The IC50 (half maximum inhibition concentration) of dapsone for 5-hydroxyeicosatetraenoic acid (5-HETE) and omega-OH-LTB4 amounted to similar values (5-HETE: 9 microM; omega-OH-LTB4: 11 microM). The inhibition of the conversion of arachidonic acid to several eicosanoids mainly suggests an effect on the 5-LOX enzyme. The comparison of inhibition values between intact PMN and a cell-free system (by sonification) indicates an additional effect of dapsone upon enzymes other than 5-LOX. Since the concentrations used are comparable with therapeutic conditions, dapsone may exert part of its anti-inflammatory effect by prevention of the generation of 5-LOX metabolites.

Calcimycin↗

Acute dapsone poisoning: clinical features and pharmacokinetic studies.

A case of acute dapsone poisoning in a 57 year old man is reported. Peak plasma dapsone concentrations of 18.8 mg/l were observed 20 hours after ingestion, and methaemoglobin concentrations fell in parallel with dapsone. Plasma dapsone concentrations declined mono-exponentially with time, and the half-life (29.7 hours) was similar to that described in subjects receiving conventional doses. Moreover, the ratio of monoacetyl-dapsone (MADDS) to dapsone remained constant as plasma concentrations fell. These observations suggest that N-acetylation of dapsone was not saturated even at the toxic concentrations observed.

Acute Disease↗

Successful desensitization to dapsone for Pneumocystis carinii prophylaxis in an HIV-positive patient.

OBJECTIVE: To report a case of successful desensitization to dapsone for Pneumocystis carinii pneumonia (PCP) prophylaxis in a patient unable to tolerate trimethoprim/sulfamethoxazole (TMP/SMX) desensitization or dapsone at standard doses. CASE SUMMARY: A 37-year-old HIV-positive African-American man was treated for pneumonia with TMP/SMX and then continued on the drug for PCP prophylaxis. After experiencing a pruritic maculopapular rash with TMP/SMX, both at standard doses and after attempting a desensitization regimen to the drug, he was started on dapsone for PCP prophylaxis. He experienced a rash and fever after taking dapsone at standard PCP prophylactic doses. At this time, an 18-day oral dapsone rechallenge by dose escalation was attempted, and it was well tolerated. CONCLUSIONS: This case suggests that utilization of a dapsone desensitization regimen may permit a viable treatment option in patients previously thought to be intolerant to the agent. More regimens of this type should be attempted and the results published, using both dapsone and TMP/SMX, so that standard desensitization treatment guidelines may eventually be adopted.

AIDS-Related Opportunistic Infections↗

Dapsone at onset of diabetes lowers glycated hemoglobin and delays death in NOD mice.

Dapsone (4,4'-diaminodiphenyl sulfone) is a compound that has a large clinical experience due to its antimicrobial effects against mycobacterium leprae, the causative agent of leprosy. It is increasingly used in a number of clinical situations where inflammation may play an ancillary role. An inhibitory effect of the drug or lack thereof in the cumulative incidence or propagation of diabetes mellitus in the NOD mouse has mechanistic as well as therapeutic implications. We previously showed that dapsone administered continuously as a percentage of food to NOD mice inhibits the cumulative incidence of diabetes in a dose dependent fashion. In the present experiment, female NOD litter mates were randomized to receive dapsone (0.001% w/w as a percentage of food) at onset of diabetes. There were no differences in weight, blood glucose, or glycated hemoglobin at 10 weeks of age among the animals that were ultimately to receive dapsone (n = 10), mouse chow alone (n = 9), or those who did not develop diabetes (n = 3). The mean time to onset of diabetes, mean blood glucose at onset, and mean glycated hemoglobin at onset did not differ between animals who did or did not receive dapsone. Animals receiving dapsone had significantly (p < or = 0.03) lower glycated hemoglobin at weeks 2, 3, and 4 following the onset of diabetes and lived significantly longer following diagnosis of diabetes (7 vs. 4 weeks, p < 0.05). In conclusion, dapsone modulates the progression of autoimmune diabetes in the NOD mouse even when administered after the initiation of hyperglycemia.

Age of Onset↗

Intermittent trimethoprim-sulfamethoxazole compared with dapsone-pyrimethamine for the simultaneous primary prophylaxis of Pneumocystis pneumonia and toxoplasmosis in patients infected with HIV.

OBJECTIVE: To evaluate the efficacy and safety of two oral, intermittent drug regimens for the simultaneous primary prophylaxis of Pneumocystis carinii pneumonia and toxoplasmosis in patients with HIV infection. DESIGN: Nonblinded randomized study: Patients received either 1) trimethoprim-sulfamethoxazole (160 mg-800 mg orally twice a day on a thrice weekly regimen) or 2) 100 mg of dapsone plus 50 mg of pyrimethamine orally twice weekly. SETTING: University teaching hospital in Barcelona. PATIENTS: 230 patients infected with HIV who had CD4 cell counts of less than 200 x 10(6)/L and who had not previously had P. carinii pneumonia or toxoplasmosis. MEASUREMENTS: Clinical and biological evaluations; adverse reactions; and end points of P. carinii pneumonia, toxoplasmosis, and death. RESULTS: After a median follow-up of 430 days, 6 (6.3%) of 96 evaluable patients receiving dapsone-pyrimethamine and 0 of 104 evaluable patients receiving trimethoprim-sulfamethoxazole developed P. carinii pneumonia (P < 0.0001). The cumulative rates of P. carinii pneumonia at 12 and 24 months were 0% and 0% for patients receiving trimethoprim-sulfamethoxazole and 4% and 11% for patients receiving dapsone-pyrimethamine (Mantel-Cox, P = 0.014). However, only one episode of P. carinii pneumonia developed while patients were taking these drugs. No differences were observed for toxoplasmosis (one episode in the trimethoprim-sulfamethoxazole arm and two in the dapsone-pyrimethamine arm), with cumulative rates at 12 and 24 months of 0% and 4% for the trimethoprim-sulfamethoxazole arm and 2% and 7% for the dapsone-pyrimethamine arm (P = 0.65). Similar mortality rates were observed during follow-up (P = 0.85). Nineteen patients (9.5%) discontinued therapy with the drugs because of adverse effects: Ten were in the trimethoprim-sulfamethoxazole arm and 9 were in the dapsone-pyrimethamine arm (P = 0.95). CONCLUSIONS: Thrice-weekly trimethoprim-sulfamethoxazole is an effective and well-tolerated regimen for the simultaneous primary prophylaxis of P. carinii pneumonia and toxoplasmosis in patients infected with HIV. Twice-weekly dapsone-pyrimethamine appears to be a safe and effective alternative.

AIDS-Related Opportunistic Infections↗