Praziquantel for the treatment of schistosomiasis mansoni during pregnancy

In a prospective study carried out in New Halfa Teaching Hospital, in eastern Sudan, between June 2001 and April 2003, 25 pregnant Sudanese women with schistosomiasis mansoni were each treated with a single oral dose of praziquantel (PZQ), at 40 mg/kg. The drug was given to six (24%), 12 (48%) and seven (28%) of the women during the first, second and third trimesters of their pregnancies, respectively. The patients were followed-up until delivery and their babies were followed-up until they were 1 year old. Although one patient, who received PZQ after 10 weeks of gestation, aborted (3 weeks post-treatment), this frequency of abortion is similar to that seen in the local community. None of the treated women died, and there were no stillbirths or congenital abnormalities in the newborn babies. Although this is a small trial, it appears that PZQ is a safe drug to use against schistosomiasis mansoni, even during the first trimester of pregnancy.

A multi-centre study of community-directed ivermectin distributors' (CDDs') involvement in other healthcare and development programme activities in Cameroon, Togo, Sudan, Nigeria and Uganda

A multi-centre study to determine whether community-directed distributors (CDDs) are capable of carrying out additional healthcare and developmental activities in their communities was carried out in Cameroon, Nigeria, Sudan, Uganda and Togo to ascertain the potential effects of their involvement on the implementation of community-directed treatment with ivermectin (CDTI). Both quantitative and qualitative methods were used to collect data from households, community-directed distributors, community leaders, and health workers. The results showed no major decrease in the CDDs' performance in CDTI: on the contrary, the involvement of CDDs in other health and development activities motivated them to perform their CDTI functions better. However, the results did not show any significant increase in therapeutic coverage of ivermectin distribution. The expansion of the CDDs' experience to include additional healthcare and development related activities would be of interest to onchocerciasis control programmes--it will strengthen CDTI sustainability through greater integration.

APOC's strategy of community-directed treatment with ivermectin (CDTI) and its potential for providing additional health services to the poorest populations. African Programme for Onchocerciasis Control

Since its inauguration in 1995, the African Programme for Onchocerciasis Control (APOC) has made significant progress towards achieving its main objective: to establish sustainable community-directed treatment with ivermectin (CDTI) in onchocerciasis-endemic areas outside of the remit of the Onchocerciasis Control Programme in West Africa (OCP). In the year 2000, the programme, in partnership with governments, non-governmental organizations and the endemic communities themselves, succeeded in treating 20,298,138 individuals in 49,654 communities in 63 projects in 14 countries. Besides the distribution of ivermectin, the programme has strengthened primary healthcare (PHC) through capacity-building, mobilization of resources and empowerment of communities. The community-directed-treatment approach is a model that can be adopted in developing other community-based health programmes. The approach has also made it possible to bring to the poor some measure of intervention in some other healthcare programmes, such as those for malaria control, eye care, maternal and child health, nutrition and immunization. CDTI presents, at all stages of its implementation, a unique window of opportunity for promoting the functional integration of healthcare activities. For this to be done successfully and in a co-ordinated manner, adequate funding of CDTI within PHC is as important as an effective sensitization of the relevant policy-makers, healthworkers and communities on the value of integration (accompanied by appropriate training at all levels). Evaluation of the experiences in integration of health services, particularly at community level, is crucial to the success of the integration.

Pharmacokinetic interaction between praziquantel and albendazole in Sudanese men

It has been suggested that praziquantel (40 mg/kg) and albendazole (400 mg) administered together may have a synergistic effect on intestinal parasites. In the present study, the pharmacokinetics of these agents, alone and in combination, were investigated in the presence and absence of food in two groups of Sudanese males. The results indicated that praziquantel pharmacokinetics were not effected by co-administration of albendazole although, in the presence of food, the area under the curve (AUC(0-infinity)) of praziquantel increased 2.6 fold. The AUC(0-infinity) of albendazole sulphoxide (the active metabolite of albendazole) increased 4.5-fold when administered with praziquantel, eight-fold when given with food and 12-fold when given with praziquantel and food. The balance between the therapeutic efficacy of this combination of drugs and its safety profile needs to be studied, especially with regard to albendazole.

Propranolol reduces mortality in patients with portal hypertension secondary to schistosomiasis

Although beta-adrenoceptor antagonists improve morbidity and mortality in patients with portal hypertension associated with cirrhosis, this has not been demonstrated in non-cirrhotic patients. In the present, double-blind, 24-month, prospective study of patients with endoscopically-proven varices and ultrasonographically-confirmed hepatic fibrosis, the effects of propranolol 160 mg LA and placebo on the incidence of rebleeding and mortality were compared in 82 patients with portal hypertension secondary to schistosomiasis. The results, analysed on intention-to-treat basis, indicated a reduction in rebleeding (median time to rebleeding 589 days for propanol v. 252 days for placebo; P < 0.02) and increased survival in the propranolol-treated patients (three deaths v. seven deaths on placebo; P < 0.02). Fifteen patients withdrew from the propranolol group and 18 from the placebo group. A positive prognostic indicator was a large portal vein diameter whereas a small liver size indicated a negative outcome.

Liver morphology and function in visceral leishmaniasis (Kala-azar)

AIM

To study the morphology and function of the liver in visceral leishmaniasis (Kala-azar).

METHODS

Percutaneous liver biopsy specimens from 18 patients with confirmed visceral leishmaniasis were examined under light and electron microscopy before and after treatment with pentovalent antimony. The tissue was also examined for hepatitis B surface and core antigens using immunoperoxidase staining. Liver function was investigated in nine patients before and after treatment.

RESULTS

Specimens before treatment showed Kupffer cells and macrophages colonised by leishmania parasites in 40% of cases. A chronic mononuclear cell infiltrate had affected the portal tracts and lobules. Ballooning degeneration of the hepatocytes, fibrosis of the terminal hepatic venules, and pericellular fibrosis were common findings. The fibrosis was related to Ito cells transforming to fibroblast-like cells. None of the patients had hepatitis B infection. All patients had biochemical evidence of liver dysfunction before treatment. Liver function improved after treatment.

CONCLUSION

Visceral leishmaniasis causes morphological and functional disturbance in the liver. Focal fibrosis rather than cirrhosis occurs. The exact aetiology of hepatic damage is unclear but may have an immunological basis.

Oesophageal varices in a region of the Sudan endemic for Schistosoma mansoni

In a field study of two villages in the Gezira, an area of the Sudan endemic for Schistosoma mansoni, liver ultrasonography was used to detect subjects with Symmers' hepatic periportal fibrosis, some of whom underwent oesophagoscopy to detect oesophageal varices. The prevalence of oesophageal varices in subjects undergoing oesophagoscopy was 54 per cent and 67 per cent respectively, occurring mainly in males aged about 30 years. The varices were usually asymptomatic. Symptomatic varices (with a positive history of haematemesis) occurred in 4 per cent and 3 per cent respectively of subjects with sonographic evidence of liver periportal fibrosis. By detecting oesophageal varices in an asymptomatic phase, hepatic ultrasonography and fibreoptic oesophagoscopy may elucidate the natural history of the varices and their response to periodic anti-schistosomal chemotherapy.

Enzyme activities and protein concentrations in serum of patients with hepatosplenic schistosomiasis

The hepatosplenic form of Schistosoma mansoni infection contributes considerably to morbidity and mortality in endemic areas. The present study investigated serum protein concentrations and serum enzyme activities of 58 Sudanese patients with hepatosplenic schistosomiasis. All of them had a history of infection with S. mansoni and one or several episodes of oesophageal bleeding due to portal hypertension. Diagnosis was based on clinical (n = 24), ultrasonographical (n = 18) and histological (n = 16) grounds. The control group consisted of 40 Sudanese healthy blood donors. Serum albumin was found to be significantly lower in patients with hepatosplenic schistosomiasis (median = 37 g/l) than in controls (median = 47 g/l). Serum enzyme analysis revealed only minimal alterations of cellular enzyme activities, but a marked decrease of cholinesterase activity. Serum albumin concentration correlated significantly with cholinesterase activity. We conclude that liver function in patients with schistosomiasis and portal hypertension is partially disturbed. Low serum albumin and low cholinesterase activity reflected an impaired protein synthesis of the liver. Destruction of parenchymal liver cells was mild or absent.

Significance of eosinophiluria in urinary schistosomiasis. A study using Hansel's stain and electron microscopy

Urine deposit smears of 58 patients with urinary schistosomiasis, 20 with acute glomerulonephritis, and 14 with urinary stones were stained with Hansel's stain. Eosinophiluria was seen in all cases of urinary schistosomiasis (median 0.73 [73%] of urinary white blood cells [WBCs]); 13 (65%) of those with acute glomerulonephritis (median 0.03 [3%] of urinary WBCs); and 2 (14%) patients with urinary stones (0.01 [1%] and 0.05 [5%] of urinary WBCs). Other features included the presence of ova and activated macrophages and giant cells in urinary schistosomiasis, an increased number of mononuclear cells and stained cellular casts in acute glomerulonephritis, and an increased number of neutrophils in urinary stones. In schistosomiasis, urine differential leukocyte counts were unrelated to those of the blood. Moreover, urine eosinophil percentages were always higher than those in the blood. Thus, in urinary schistosomiasis, eosinophiluria could be explained by exudation, sloughing of granulomata, as well as bleeding from the urinary tract surface. Electron microscopic examination confirmed that most of the leukocytes were eosinophils. Some of these were adherent and degranulating over ova with variable miracidial damage. Urine eosinophil and egg counts were not correlated to each other. Staining urine deposit smears, with the use of Hansel's stain, is useful in the investigation of hematuria. Heavy eosinophiluria and few mononuclear cells favor the diagnosis of urinary schistosomiasis rather than acute glomerulonephritis or urinary stones. These results diminish the value of eosinophiluria as corroborative evidence of drug-induced interstitial nephritis in areas of endemic urinary schistosomiasis.

Morbidity associated with Schistosoma mansoni infection as determined by ultrasound: a study in Gezira, Sudan

Previous studies demonstrated the usefulness of ultrasonography in diagnosing Symmers' periportal fibrosis. The prevalence and grade of Symmers' fibrosis was determined using ultrasonography in two villages in the Gezira region of Sudan and compared to standard clinical criteria. In El Dar 18% and Abu Jin 13% of the population had Symmers' fibrosis by ultrasonography. In contrast, only 6.3% in El Dar and 5.2% in Abu Jin with Symmers' fibrosis had splenomegaly, thus most of the population with Symmers' fibrosis would not have been diagnosed clinically. The degree of involvement was estimated by a set of previously defined criteria which ranged from mild (grade 1) to severe (grade 3). Involvement was greatest between 20-30 years and followed the age peak egg excretion rate by 5 years. The prevalence and degree of splenomegaly as well as the portal and splenic vein diameters increased with grade. The presence of hepatomegaly did not correlate with increasing grade. Ultrasonography is a much more sensitive technique than clinical evaluation in estimating the degree of Symmers' fibrosis in this population. A more accurate assessment of involvement will allow a more rational approach to the study of the pathophysiology of this complication and its eventual control.

Diagnosis of pathologically confirmed Symmers' periportal fibrosis by ultrasonography: a prospective blinded study

Symmers' periportal fibrosis of the liver is the major cause of morbidity and mortality in Schistosoma mansoni infection. The diagnosis is best established definitively by a wedge biopsy of the liver. The ability of abdominal ultrasonography to diagnose this condition was prospectively compared with two independent pathological examinations of wedge biopsies of the liver. Both pathologists and the ultrasonographer were unaware of the clinical diagnosis and each other's findings. Twenty-eight of 41 patients had Symmers' fibrosis by pathological examination and all were diagnosed correctly by ultrasonography prior to surgery. Symmers' fibrosis was not diagnosed by ultrasound in any of 10 patients without Symmers' fibrosis on biopsy. In 3 patients the diagnosis of Symmers' fibrosis was uncertain because the pathologists disagreed as to its presence. These results confirm the findings of previous studies and establish that ultrasonography is at least as sensitive as wedge biopsy in diagnosing Symmers' fibrosis.

Paraphenylenediamine induced acute tubular necrosis following hair dye ingestion

A case is reported of paraphenylenediamine toxicity following hair dye ingestion. Renal biopsy showed histology typical of acute tubular necrosis.

Disposition of oral metronidazole in hepatic cirrhosis and in hepatosplenic schistosomiasis

The pharmacokinetics of metronidazole 500 mg orally were determined in patients with hepatosplenic schistosomiasis and normal controls in the Sudan, and in cirrhotics and normal controls in Bristol. Plasma metronidazole levels were above the minimum inhibitory concentration of most susceptible anaerobic bacteria for four to six hours post-dose in all groups. Liver disease did not markedly influence the disposition of single oral doses of metronidazole. Cirrhotics showed some prolongation of metronidazole half-life, and somewhat greater metronidazole concentrations 24 hours after the dose. Concentrations of the oxidative metabolite of metronidazole were lower in Sudanese patients and normal controls than in normal British subjects. In chronic liver disease adjustment of metronidazole dosage is probably not required provided renal function is unimpaired.

A single dose comparison of piretanide and bumetanide in congestive cardiac failure

1 This study has compared the diuresis produced by a single oral administration of 6 mg piretanide, 9 mg piretanide and 1 mg bumetanide in a group of nine patients with cardiac failure using a balanced randomized design. 2 The natriuresis and kaliuresis produced in the first 6 h after administration of piretanide 9 mg and bumetanide 1 mg were similar. Piretanide 6 mg produced a lesser response. 3 There was evidence of sodium and water conservation following the diuresis for up to 48 h with all three treatments. 4 The patterns of urate and calcium excretion were similar for the two diuretics.

Antipyrine clearance per unit volume liver: an assessment of hepatic function in chronic liver disease

Liver size has been estimated clinically and by a non-invasive ultrasound technique in 16 normal subjects, 16 patients with cirrhosis, 10 patients with chronic biliary obstruction, and three patients with primary hepatoma. Antipyrine disposition was also measured in each subject. Hepatomegaly was not clinically detectable until there was approximately a 20% increase in liver size. Additional increases in size correlated significantly with clinical estimates of hepatomegaly. Antipyrine clearance had a three-fold range in normal subjects. Its mean value was significantly reduced in each subgroup of patients with liver disease. However, 48% of patients with liver disease had values within the normal range. In normal subjects there was a significant correlation between antipyrine clearance and liver volume. Thus, intersubject variation in clearance normalised for liver volume was less than clearance alone. Antipyrine clearance normalised for liver volume in patients with liver disease was significantly lower than in normal subjects and there was no overlap with normal subjects. In conclusion, assessment of drug metabolising efficiency per unit volume of liver increased the discrimination in differentiating subjects with normal from abnormal livers.

Drug metabolism in malnourished children: a study with antipyrine

The effect of malnutrition on hepatic drug-metabolising enzymes was investigated in 8 Sudanese children aged between 9 and 12.5 years using as a model the drug antipyrine. Antipyrine half-life and clearance were measured in the malnourished state and after 3 or 4 weeks of good nutrition. Associated with the improvement in nutritional state was a shortening of antipyrine half-life and an increase in its clearance. There was also a rise in serum triiodothyronine. It is concluded that poor nutrition is associated with impairment of drug metabolic capacity and that many factors are responsible.

The features of hepatic enzyme induction with glutethimide in man

1 Sequential measurements of D-glucaric acid excretion were made in six healthy volunteers before, during and after 3 weeks' daily medication with glutethimide 500 mg. 2 There was a rapid rise in D-glucaric acid excretion within 2 days of starting medication and a rapid decline when it was stopped. 3 Antipyrine clearance and indocyanine green clearance were measured before and at the end of the 3 weeks' medication. 4 There was a 55% increase in antipyrine clearance but no change in indocyanine green clearance. 5 There was no correlation between antipyrine clearance and D-glucaric acid excretion. 6 Glutethimide causes rapid enzyme induction in man without concomitant rise in hepatic blood flow.

Antipyrine disposition and liver size in the elderly

This study has examined the contribution of decrease in liver size to the decline in drug metabolising capacity which occurs with ageing. Liver volume and antipyrine kinetics were measured in two groups of healthy individuals aged 20 to 29 years and 75 to 86 years and in a group of hospitalised patients aged 70 to 89 years. Liver volume was reduced in both groups of elderly people compared to the young group. Antipyrine plasma half-life was prolonged and antipyrine clearance was reduced in the group of elderly normal individuals. In this group the index--antipyrine clearance per unit liver volume--was also reduced in comparison to that of the young group. Measurements of antipyrine elimination in the hospitalised elderly group did not differ significantly from those in the young group. It is concluded that both decreased liver mass and decreased hepatic enzyme activity contribute to the impairment of drug oxidation which occurs in the elderly and which may warrant a reduction in dosage of some drugs. However, differences have been demonstrated between groups of elderly people suggesting that under certain circumstances standard doses of such drugs may be normally tolerated.

Decreased first-pass metabolism of labetalol in chronic liver disease

The effect of chronic liver disease on the rate of elimination and extent of "first-pass" metabolism of labetalol was studied. Pharmacokinetic measurements were made after both oral and intravenous administration to seven healthy subjects and to 10 patients with chronic liver disease. Plasma half life was similar in the two groups. Plasma concentrations were considerably higher in the patients than in the healthy subjects after oral administration but similar after intravenous injection. Thus the bioavailability of labetalol was increased in liver disease due to reduced first-pass metabolism. Bioavailability in the group of patients correlated negatively with serum albumin concentration. There were falls in supine heart rate and blood pressure which tended to be greater after oral administration in the patients with liver disease, suggesting an exaggerated response related to the increased bioavailability. Oral dosage requirements of labetalol and possibly other drugs susceptible to first-pass metabolism are reduced in the presence of liver disease.

Drug metabolism in hepatosplenic schistosomiasis in the Sudan: a study with antipyrine

The disposition of antipyrine following oral administration of 1200 mg has been investigated in 10 patients with histologically confirmed hepatosplenic schistosomiasis and 11 normal subjects living in Sudan. Drug metabolising activity as assessed by antipyrine clearance was similar in patients when compared with normal controls. We conclude that antipyrine disposition is normal in patients with clinically compensated hepatosplenic schistosomiasis.

Racial differences in drug metabolizing ability: a study with antipyrine in the Sudan

The kinetic disposition of antipyrine following oral administration of 1,200 mg has been investigated in 11 normal Sudanese subjects living in Sudan, 9 Sudanese subjects living in England for at least 2 yr, and 19 normal English subjects living in England. Sudanese subjects living in Sudan had significantly lower mean antipyrine clearance and higher volume of distribution than the English group (-28% and +30%, respectively). There was no significant difference for antipyrine clearance between English and Sudanese subjects living in England, but the volume of distribution of antipyrine was higher (16%) in the Sudanese subjects. The mean half-lives of the three groups differed significantly. We conclude that differences in disposition of antipyrine between native English and Sudanese populations was predominantly due to environmental factors.

Effects of piretanide, bumetanide and frusemide on electrolyte and urate excretion in normal subjects

1. The pharmacological actions of a new short acting loop diuretic were investigated in nine healthy male subjects and compared with those of frusemide and bumetanide. Subjects received 6 mg piretanide/day, 40 mg frusemide/day or 1 mg bumetanide/day for a period of 1 week. 2. Comparison of effects following the first dose administered showed that 6 mg piretanide is of similar potency to 40 mg frusemide in terms of diuresis, natriuresis and kaliuresis but is less potent than 1 mg bumetanide. 3. All three diuretics caused a decrease in urate excretion and a rise in serum uric acid. 4. Piretanide was well tolerated. Further investigation is required to ascertain what clinical advantage it offers over frusemide and bumetanide.

Effects of an oral contraceptive on hepatic size and antipyrine metabolism in premenopausal women

Liver volume and antipyrine disposition have been investigated in healthy premenopausal women who received 30 microgram ethinyl oestradiol + 500 microgram dl-norgesterol as an oral contraceptive. Six months' treatment was associated with a 17% increase in liver volume while no change occurred in age-matched control subjects. In the same subjects the contraceptive decreased antipyrine clearance by 21%. Thus the contraceptive markedly reduced drug-metabolizing activity per unit volume of liver by 33%. In additional subjects, discontinuation of the contraceptive resulted in a 30% increase in antipyrine clearance. These observations confirm that conventional oral contraceptive therapy to premenopausal women increases hepatic size and that it is a potent inhibitor of drug-metabolizing activity.

Influence of probenecid and spironolactone on furosemide kinetics and dynamics in man

The pharmacokinetics and pharmacodynamics following administration of furosemide (40 mg intravenously) have been studied before and after treatment with probenecid (0.5 gm orally every 6 hr for 3 days) and spironolactone (200-mg initial oral dose followed by 50 mg every 6 hr for 3 days) in 6 normal male subjects. Urine losses during each study period were replaced with saline-dextrose-KCl intravenously. The study was performed with the use of a Latin-square design. Probenecid pretreatment induced significant reductions in renal clearance of furosemide by 78%, the extrarenal clearance by 56%, and the volume of distribution by 52%. As a consequence, furosemide half-life was increased by 54%. Probenecid significantly reduced the rate of sodium excretion at all plasma concentrations of furosemide, but the ratio between urinary furosemide concentration and urinary sodium concentration was not altered. Since the proportion of furosemide excreted unchanged in the urine was not markedly changed, total diuretic response was not influenced by probenecid. There was no evidence of any pharmacokinetic interaction between spironolactone and furosemide. The relationship of furosemide kinetics to dynamics observed in these studies confirms that, in man, the diuretic response is determined by drug that reaches the renal tubule rather than the drug level in plasma.

Determinants of response to frusemide in normal subjects

1 The pharmacokinetic and diuretic response of frusemide have been investigated in six normal subjects. Frusemide (80 mg) was administered (a) intravenously to unstressed subjects, (b) orally to unstressed subjects, (c) orally to sodium depleted subjects who had received 80 mg oral frusemide 36 h previously followed by a 20 mmol sodium, 160 mmol potassium diet.

2 After i.v. administration, the logarithmic plasma concentration-time curve was biexponential. There was a linear relationship between the frusemide plasma concentration in the β-phase of elimination and the rate of sodium excretion. Urinary clearance of frusemide was 60% of total plasma clearance, similarly recovery of frusemide in the urine over 36 h was 65% of the dose administered. These observations suggested an extrarenal route of elimination.

3 After oral administration there was also a linear relationship between frusemide plasma concentration and rate of sodium excretion. Oral bioavailability estimated from the ratio of the areas under the plasma concentration-time curve (AUC) and urine recovery over 36 h after i.v. and oral administration was approximately 50%, yet the diuretic response was similar.

4 The AUC of the β-phase after i.v. administration was similar to the total AUC after oral administration suggesting that response was related to drug present in a tissue pool rather than in plasma. After sodium depletion, there was no change in frusemide kinetics, however the diuretic response decreased. Once again, there was a significant relationship between plasma concentration and rate of sodium excretion. This relationship during the elimination phase after oral administration to sodium depleted subjects was significantly shifted to the right compared to the elimination phase after oral administration to unstressed subjects, suggesting a change in plasma concentration response.

5 In conclusion, the response to frusemide is determined by the concentration of drug in the tissue comparement. This response is modified by factors controlling sodium homeostasis.

Ultrasonic measurement of liver size

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