Comparative clinical trial of two-fixed combinations dihydroartemisinin-napthoquine-trimethoprim (DNP) and artemether-lumefantrine (Coartem/Riamet) in the treatment of acute uncomplicated falciparum malaria in Thailand.

An open randomized comparison of two-fixed dose artemisinin derivative-containing combination regimens was conducted in adults with acute uncomplicated multidrug resistant falciparum malaria in Thailand. DNP, a combination of dihydroartemisinin with napthoquine and trimethoprim developed recently in China, has been evaluated in China, Vietnam, Cambodia and Thailand. This study was performed to compare the safety, tolerability and efficacy of DNP and artemether-lumefantrine/Coartem. One hundred and thirty eligible uncomplicated falciparum malaria patients were enrolled into the study. Patients were randomly assigned in a 2:1 ratio into group A, which received DNP one tablet twice a day for one day; and group B, which received Coartem/Riamet four tablets twice a day for 3 days. The cure rates at 28-day were 99% and 97% in group A and group B, respectively. No serious adverse events occurred. We concluded that both DNP and Coartem/ Riamet were safe, well tolerated and highly efficacious in the treatment of acute uncomplicated falciparum malaria in Thailand.

An open randomized clinical trial of Artecom vs artesunate-mefloquine in the treatment of acute uncomplicated falciparum malaria in Thailand.

The efficacy and safety of Artecom were assessed in an open randomized trial in adults presenting with acute, uncomplicated Plasmodium falciparum malaria in Thailand. Three hundred and fifty-two patients were randomly enroled at the ratio of 2:1 into group A:B and received Artecom (group A) and the standard combination of artesunate and mefloquine (group B) respectively. All patients had rapid initial clinical and parasitological responses. There were no significant differences in fever clearance time and parasite clearance time between the two groups. The 28-day cure rates were high as 97% in both groups. Artecom was effective and well-tolerated as artesunate-mefloquine, the current treatment in this area of multidrug-resistant P. falciparum malaria.

A comparative clinical trial of combinations of dihydroartemisinin plus azithromycin and dihydroartemisinin plus mefloquine for treatment of multidrug resistant falciparum malaria.

With the deteriorating situation of multidrug resistant falciparum malaria, a new drug or drugs in combinations are urgently needed. We conducted a study comparing a combination of dihydroartemisinin 240 mg and mefloquine 1,250 mg given over 3 days (Group 1) and a combination of dihydroartemisinin 240 mg and azithromycin 1,500 mg given over 3 days (Group 2), to determine safety, efficacy and tolerability. All of the patients stayed in a non-malaria endemic area during the study. By the third day after drug administration, most patients were free of parasites and none had serious adverse events. The cure rates at day 28 were 100% and 69.7% in Group 1 and Group 2, respectively (p<0.01). We conclude that a combination of dihydroartemisnin and azithromycin was safe and effective and may be another interesting regimen of the treatment of uncomplicated multidrug resistant Plasmodium falciparum malaria in Thailand.

Effect of primaquine standard dose (15 mg/day for 14 days) in the treatment of vivax malaria patients in Thailand.

Primaquine (8-aminoquinoline), the only effective drug to prevent relapses of the persistent liver forms of Plasmodium vivax and Plasmodium ovale, can induce hemolytic anemia in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. The severity varies considerably among affected individuals. Three hundred and sixty-four Plasmodium vivax cases (342 G6PD-normal and 22 G6PD-deficient) were given a 3-day course of chloroquine (total dose 1,500 mg) followed by primaquine 15 mg a day for 14 days and completed a 28-day follow-up. All G6PD-deficient patients were male; there were no relapses or serious adverse events during the study. Although a significant decrease in hematocrit levels and an increase in the percent reduction of hematocrit levels were observed on day 7 (34.9+/-5.0 vs 26.7+/-5.4; (-1.2)+/-14.4 vs (-24.5) +/-13.9 respectively) and on day 14 (35.7+/-4.3 vs 30.9+/-3.1; 1.6+/-17.8 vs (-11.0) +/-19.3 respectively) blood transfusion was not required. Daily doses of 15 mg of primaquine for 14 days following a full course of chloroquine when prescribed to Thai G6PD deficient patients where Mahidol variant is predominant, are relatively safe.

The combined treatment of interferon alpha-2a and thymosin alpha 1 for chronic hepatitis C: the 48 weeks end of treatment results.

The efficacy and safety of IFN alpha 2a and Thymosin alpha1 combination therapy in patients with chronic hepatitis C were determined. Twelve chronic hepatitis C patients (9 M, 3F), with positive HCV-RNA and histology compatible with chronic hepatitis C were included in this open, prospective study. Each patient received a combination therapy of IFN alpha 2a 3 mU s.c. TIW and Thymosin alpha1 1.6 mg s.c. twice a week for 52 weeks. Up to the present, 11 patients are still being followed-up after the end of 52 weeks' treatment. One patient dropped out after 32 weeks of follow-up due to noncompliance. Responses to treatment were evaluated by measuring serum HCV-RNA levels determined by RT-PCR. and serum amino transferases at the end of 48 weeks of treatment (end of treatment response: ETR). There were 8 naive and 4 previously IFN treated patients with partial response with a mean age of 45.0 +/- 10.1 (mean +/- SD). The mean duration from diagnosis until treatment was 25.1 +/- 22.9 months. The mean AST, ALT, and HCV-RNA levels before treatment were 79.5 +/- 36.8 U/L, 128.3 +/- 68.5 U/L, and 3.9+1.9 x 10(5) copies/ml respectively. Serum AST, ALT, and HCV-RNA levels were significantly lower at week 24 and 48 after treatment compared to before treatment (p<0.05). Of 11 cases, complete HCV-RNA clearance at week 24 was noted in 33.3 per cent, whereas, normal alanine aminotransferase values (ALT < 40 U/L) were observed in 41.7 per cent of patients. Complete HCV-RNA clearance and normal alanine aminotransferase at week 48 were seen in 45.5 per cent of the patients. At the end of week 48, complete response occurred in 4 of 5 naive patients. Minor side effects were observed during treatment with this combination therapy and these included myalgia (33.3%), mild form of alopecia (33.3%), and weight loss (8.3%). In patients with chronic hepatitis C, Interferon alpha 2a and Thymosin alpha1 combination therapy produced a good response rate especially in naive patients with acceptable safety profile. The sustained response will be determined after the completion of follow-up for another 6 months.

Clinical trial of halofantrine with modified doses for treatment of malaria in the hospital for tropical diseases.

The spread of falciparum malaria resistant to chloroquine all over Southeast Asian continent has led to increasing use of alternative antimalarial drugs. Halofantrine has been shown to be effective against multidrug resistant Plasmodium falciparum. One hundred and twenty falciparum malaria cases were randomly assigned to one of three different halofantrine regimes. Group I (HA1) received 500 mg three times daily for 3 days (total dose: 4,500 mg), group II (HA2) received 500 mg three times daily for the first and the third day (total dose: 3,000 mg) and group III (HA3) received 500 mg three times for one day followed by 500 mg once daily for 7 days (total dose: 4,500 mg). No significant difference in the cure rate was observed among the three regimes (cure rate: 89%, 73%, 97% respectively). However, the cure rate was significantly higher in the HA3 group when compared to the HA2 group. There were no overt cardiac problems seen in this study. Thus, halofantrine has high efficacy in the recommended treatment dose of 500 mg three times after meals on the first day followed by 500 mg once a day after a meal for 7 days (total dose: 4,500 mg).

Adenocarcinoma of the pancreas: the clinical experience of 45 histopathologically proven patients, a 6 year study.

A retrospective study of 45 cases of adenocarcinoma of the pancreas at Chulalongkorn University Hospital from 1993 to 1998 was reviewed by clinical and histopathological criteria. Male and female ratio was 25:20. The mean age of the patients was 59.5 +/- 10.0 years. The common presenting symptoms and signs were epigastric discomfort (80.0%), weight loss (60.0%) and jaundice (51.1%). Twenty four patients (53.3%) were screened for a tumor marker (CA 19-9) and 87.5 per cent of these had high level of CA 19-9 (> 37 IU/ml). Thirty five patients (77.8%) had tumors located in the head of the pancreas. Most of the cases were investigated by using radiological imaging (ultrasonography or computerized tomography of the abdomen). Thirty five histopathological data (77.8%) were made by the operation, and the rest (22.2%) were performed by a fine needle aspiration from the pancreatic mass or liver metastasis. Whipple operation and the bypass procedure were the most common surgical procedures in our studies. Twenty five patients (55.6%) had post treatment complications from all modalities consisting of gastrointestinal bleeding, respiratory failure and infection. However, the mortality rate within 30 days postoperatively was 8.11 per cent which was due to blood loss during the operation and infections. The post treatment mortality rate from all modalities was 33.3 per cent. The average duration from the diagnosis until death was 82.3 days.

Frequency of early rising parasitemia in falciparum malaria treated with artemisinin derivatives.

To define the frequency of the early rising of parasitemia in falciparum malaria patients treated with artemisinin derivatives, a retrospective chart review of 497 patients admitted to the Hospital for Tropical Diseases, Bangkok in 1996 was carried out. Early rising parasitemia, defined as an increase in the parasite count over the baseline pretreatment level during the first 24 hours of treatment, was found in 59/229 episodes (25.8%) of uncomplicated, and 111/268 episodes (41.3%) of complicated falciparum malaria. All uncomplicated cases were successfully treated without developing any complications. There were 2 deaths and 13 changes of drug regimen in the complicated group. Only one of these unfavorable responses was due to parasite response. Early rising parasitemia was very common in falciparum malaria treated with artemisinin derivatives, despite their ability to clear the parasitemia, and did not indicate failure of the drug used.

Is there any artemisinin resistance in falciparum malaria?

We reported two cases of complicated falciparum malaria who had poor response to artesunate with delayed parasite clearance times. They were splenectomized patients who were treated with high doses of artemisinin derivatives. Our cases showed the importance of the spleen in the clearance of malaria parasites and had different clinical outcome, one fatal and one recovery. The host factors, the parasitemia count, the quality of antimalarial chemotherapy and blood level of the antimalarial drugs must be considered in relation to the causes of the delayed clearance of parasitemia.

Pseudomelanosis duodeni: association with hypertension and chronic renal failure: case report.

We present the first reported case with typical endoscopic and histological findings from Thailand. An 80-year-old man presented with chronic periumbilical abdominal pain for 3 months and melena for one week. He had had hypertension for 17 years, chronic renal failure for 4 years and gouty arthritis for 3 years. Panendoscopy was done and showed diffusely scattered small black and brown pigmentation over the stomach and duodenum. Tissue biopsies from the black pigmented lesions were taken for further microscopic and histochemical evaluation. Histological finding and special histochemical stains, Fontana stain, revealed mild chronic inflammation with accumulation of hemosiderin pigment in the lamina propria of the stomach and duodenal villi. This condition is called Pseudomelanosis duodeni. The literature of this condition was also reviewed.

Hidden Plasmodium falciparum infections.

Mixed infection of P. vivax and P. falciparum malaria frequently recorded in field survey. However mixed infection was frequently misdiagnosed as single infection due to low parasite density, difficult species identification and procedure error of microscopic examination. Our previous report showed high rates (32-33%) of P vivax infection following treatment of previously assumed to be only P. falciparum infection. In a study of 992 patients with initial presentation with P. falciparum, we found that 104 (10.5%) of patients had P. falciparum appearing during 28 days in the hospital (ranged 1-28 days) following chloroquine treatment for P. vivax. The potential for P. falciparum appearing following elimination of P. vivax must be considered in malaria treatment.