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1. We evaluated injury to the human gastric mucosa caused by low doses of aspirin and its prophylaxis by ranitidine. On two separate occasions, 30 subjects took aspirin 300 mg daily for 12 days either with or without ranitidine 150 mg, 30 min before aspirin. This dose of aspirin caused more than a 5 fold increase in gastric bleeding, from control values of 0.5 microliters 10 min-1 (95% confidence limits 0.3- 0.8 microliters 10 min-1) to 2.8 microliters 10 min-1 (1.9-4.1 microliters 10 min-1, P less than 0.01) after 5 days of aspirin. Adaptation did not occur and the gastric bleeding rates remained elevated at 3.4 microliters 10 min-1 (1.9-6.1 microliters 10 min-1) after 12 days of aspirin consumption (P less than 0.01). 2. Coadministration of ranitidine significantly raised intragastric pH and reduced aspirin induced bleeding to 1.5 microliters 10 min-1 (1.0-2.3 microliters 10 min-1) after 5 days and 1.6 (1.0-2.5 microliters 10 min- 1) after 12 days (P less than 0.05). 3. Although these values were higher than control levels our results raise the possibility that coadministration of ranitidine may reduce the incidence of peptic ulceration and gastrointestinal haemorrhage which is increasingly reported in some subjects taking low dose aspirin for vascular prophylaxis. [ABSTRACT FROM AUTHOR]

1. We investigated the effect of the haemostatic agent ethamsylate on aspirin-induced gastric mucosal bleeding. 2. Eighteen healthy subjects were studied three times: at the end of 48 h periods of treatment with (a) placebo, (b) aspirin 600 mg four times daily, (9 doses) and (c) aspirin 600 mg four times daily with each dose preceded by ethamsylate 500 mg. 3. At the end of each treatment period gastric mucosal bleeding into timed gastric washings was quantified using the orthotolidine reaction. 4. Aspirin increased bleeding from a rate on placebo of 1.2 microliters 10 min-1 geometric mean (95% confidence limits) (0.7-1.8) microliters 10 min-1 to 20.0 (11.6-34.2) microliters 10 min-1, (P less than 0.01). The rate of bleeding after aspirin preceded by ethamsylate [14.1 (8.5-23.4) microliters 10 min-1] was not significantly different from that after aspirin alone. 5. We conclude that ethamsylate does not reduce acute aspirin-induced gastric mucosal bleeding in healthy humans. [ABSTRACT FROM AUTHOR]

The oral and intravenous pharmacokinetics of labetalol were determined in five subjects before and after a 3 week course of glutethimide 500 mg/day. After glutethimide there was a significant reduction in the AUC after the oral dose of labetalol, from 40,596 +/- 11,534 (mean +/- s.e. mean) to 22,057 +/- 6,276 ng ml-1 min (2P less than 0.05), and systemic bioavailability was reduced from 30.3 +/- 2.8 to 17.0 +/- 3.5% (2P less than 0.001). There was no significant change in labetalol plasma concentration-time curve (AUC) following an intravenous dose, half- life, volume of distribution, and plasma clearance. The oral and intravenous pharmacokinetics of labetalol were determined in six subjects before and after a 3 day course of cimetidine 1.6 g/day. After cimetidine there was a significant reduction in the volume of distribution of labetalol, from 520 +/- 51 to 445 +/- 24 1 (2P less than 0.05). The AUC of labetalol after the oral dose increased by 66%, from 51,029 +/- 7,950 to 84,772 +/- 19,444 ng ml-1 min (2P = 0.06). The systemic bioavailability of labetalol increased from 25.1 +/- 2.4 to 39.0 +/- 7.6% (2P = 0.06). There was no significant change in labetalol AUC after the intravenous dose, half life, and plasma clearance. There were no significant changes in resting heart rate and supine systolic and diastolic blood pressure following labetalol plus glutethimide, or labetalol plus cimetidine.(ABSTRACT TRUNCATED AT 250 WORDS) [ABSTRACT FROM AUTHOR]

1 The effects of food on the pharmacokinetics of orally and intravenously administered labetalol were assessed in six healthy volunteers. 2 Food caused a 38% increase in the mean systemic bioavailability of labetalol: from 0.26 +/- 0.03 (mean +/- s.e. mean) to 0.36 +/- 0.05 (P less than 0.05). 3 Food caused 20% increases in the volume of distribution of labetalol: (from 567 +/- 63 to 685 +/- 76) and in plasma clearance (from 1923 +/- 417 to 2344 +/- 566 ml/min. These changes did not reach statistical significance. Food did not alter the plasma half-life of labetalol after oral or intravenous dosing. 4 Food appears to increase labetalol bioavailability by decreasing its first pass metabolism. It is suggested that this change results from transient alteration of hepatic blood flow. The drug should therefore be taken at a standard time in relation to meals to minimise intraindividual variation in bioavailability. [ABSTRACT FROM AUTHOR]

1 The effects of three day courses of propranolol 40 mg three times daily, atenolol 100 mg twice daily and labetalol 100 mg three times daily on antipyrine kinetics were examined in 13 normal subjects. 2 The mean antipyrine clearance initially was 41.3 +/- 12.4 ml/min (mean +/- s.d.) and fell to 35.0 +/- 12.1 ml/min following propranolol (P less than 0.025), 34.5 +/- 9.5 ml/min following atenolol (P less than 0.01), and 35.2 +/- 8.6 ml/min following labetalol (P less than 0.05). 3 The prolongation in antipyrine half-life was significant only following atenolol. Propranolol only caused a significant reduction in the volume of distribution of antipyrine. 4 These adrenoceptor antagonists appear to decrease antipyrine clearance in normal subjects. The reduction in antipyrine clearance was similar with all three drugs and appeared to be independent of the differing lipid solubilities and pharmacological profiles of the adrenoceptor antagonists examined. [ABSTRACT FROM AUTHOR]

1 Changes in hepatic blood flow have been estimated by measurement of single-dose indocyanine green kinetics in groups of healthy individuals. 2 The effects of change in posture, exercise and ingestion of milk on estimated hepatic blood flow have been assessed. 3 The erect posture and exercise significantly decreased ICG clearance. However, no consistent change was noted after ingestion of milk. 4 The effects of the adrenoceptor blocking drugs phenoxybenzamine, propranolol and labetalol on hepatic blood flow were also assessed. 5 Propranolol and labetalol caused a significant fall in ICG clearance in the supine position. Phenoxybenzamine did not show a consistent change. 6 Posture, exercise and adrenoceptor blockade appear to be important variables affecting hepatic blood flow. They should be considered when kinetics of high-clearance drugs are measured, and may provide a useful model for the assessment of the effects of alterations in hepatic blood flow on the clearance of drugs. [ABSTRACT FROM AUTHOR]

Eight healthy female subjects were each given (a) ketoconazole 400 mg orally, (b) ketoconazole 400 mg as a single vaginal pessary, (c) ketoconazole 800 mg as two vaginal pessaries, and (d) ketoconazole 1200 mg as three vaginal pessaries. The area under the plasma concentration time curve (AUC) after the oral dose was 51.41 +/- 10.99 mg l-1 h (mean +/- s.d.) and the half-life of ketoconazole was 2.98 +/- 1.41 h. The AUCs after vaginal administration were 0.27 +/- 0.14, 0.52 +/- 0.25, and 0.43 +/- 0.22 mg-1 l h following the 400, 800 and 1200 mg pessaries respectively. Systemic absorption of single doses of vaginally administered ketoconazole appears to be negligible in the absence of vaginal infection. There were no local or systemic side effects related to ketoconazole in these healthy volunteers. [ABSTRACT FROM AUTHOR]

Background and Aims: Nephrotoxicity is a rare idiosyncratic reaction to 5-aminosalicylate (5-ASA) therapies. The aims of this study were to describe the clinical features of this complication and identify clinically useful genetic markers so that these drugs can be avoided or so that monitoring can be intensified in high-risk patients., Methods: Inflammatory bowel disease patients were recruited from 89 sites around the world. Inclusion criteria included normal renal function prior to commencing 5-ASA, ≥50% rise in creatinine any time after starting 5-ASA, and physician opinion implicating 5-ASA strong enough to justify drug withdrawal. An adjudication panel identified definite and probable cases from structured case report forms. A genome-wide association study was then undertaken with these cases and 4109 disease controls., Results: After adjudication, 151 cases of 5-ASA-induced nephrotoxicity were identified. Sixty-eight percent of cases were males, with nephrotoxicity occurring at a median age of 39.4 years (range 6-79 years). The median time for development of renal injury after commencing 5-ASA was 3.0 years (95% confidence interval [CI] 2.3-3.7). Only 30% of cases recovered completely after drug withdrawal, with 15 patients requiring permanent renal replacement therapy. A genome-wide association study identified a suggestive association in the HLA region (p = 1×10(-7)) with 5-ASA-induced nephrotoxicity. A sub-group analysis of patients who had a renal biopsy demonstrating interstitial nephritis (n = 55) significantly strengthened this association (p = 4×10(-9), odds ratio 3.1)., Conclusions: This is the largest and most detailed study of 5-ASA-induced nephrotoxicity to date. It highlights the morbidity associated with this condition and identifies for the first time a significant genetic predisposition to drug-induced renal injury., (Copyright © 2015 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Although institutional outbreaks of pneumococcal infection have been reported, secondary cases of pneumococcal meningitis do not seem to have been described. We report two cases of pneumococcal meningitis involving the same serotype occurring in individuals with direct contact.

The effect of fish oil on the course of ulcerative colitis was investigated in a randomised blinded controlled study. Eighty seven patients received supplements of 20 ml HiEPA fish oil as triglyceride (4.5 g of eicosapentaenoic acid) or olive oil placebo daily for one year. The oils were given in addition to standard drug therapy and trial entry was stratified for disease activity. Fish oil significantly increased the eicosapentaenoic acid content of rectal mucosa to 3.2% of total fatty acids at six months, compared with 0.63% for patients on olive oil. This was associated with increased synthesis of leukotriene B5, and 53% suppression of leukotriene B4 synthesis by ionophore--stimulated neutrophils. Leukotriene B4 suppression persisted for at least two months after treatment was stopped. Treatment with fish oil resulted in measurable, but only limited clinical benefit. For patients entering the trial in relapse (n = 53), there was a significant reduction in corticosteroid requirement after one and two months treatment. There was a trend towards achieving remission (off corticosteroids) faster in the patients on fish oil, although differences were not significant. For patients in remission at trial entry or during the trial (n = 69), there was no significant difference in the rate of relapse by log rank analysis. We conclude that fish oil supplementation produces a modest corticosteroid sparing effect in active disease, but there is no benefit in maintenance therapy.

Objective: To investigate the possible therapeutic role of omeprazole, a powerful proton pump inhibitor, in unselected patients presenting with upper gastrointestinal bleeding., Design: Double blind placebo controlled parallel group study. Active treatment was omeprazole 80 mg intravenously immediately, then three doses of 40 mg intravenously at eight hourly intervals, then 40 mg orally at 12 hourly intervals. Treatment was started within 12 hours of admission and given for four days or until surgery, discharge, or death., Setting: The medical wards of University and City Hospitals, Nottingham., Subjects: 1147 consecutive patients aged 18 years or more admitted over 40 months with acute upper gastrointestinal bleeding., Main Outcome Measures: Mortality from all causes; rate of rebleeding, transfusion requirements, and operation rate; effect of treatment on endoscopic appearances at initial endoscopy., Results: Of 1147 patients included in the intention to treat analysis, 569 received placebo and 578 omeprazole. No significant differences were found between the placebo and omeprazole groups for rates of transfusion (302 (53%) placebo v 298 (52%) omeprazole), rebleeding (100 (18%) v 85 (15%)), operation (63 (11%) v 62 (11%)), and death (30 (5.3%) v 40 (6.9%)). However, there was an unexpected but significant reduction in endoscopic signs of upper gastrointestinal bleeding in patients treated with omeprazole compared with those treated with placebo (236 (45%) placebo v 176 (33%) omeprazole; p less than 0.0001)., Conclusions: Omeprazole failed to reduce mortality, rebleeding, or transfusion requirements, although the reduction in endoscopic signs of bleeding suggests that inhibition of acid may be capable of influencing intragastric bleeding. Our data do not justify the routine use of acid inhibiting drugs in the management of haematemesis and melaena.

1. An increasing body of data suggests that the antihaemostatic as well as the ulcerogenic actions of aspirin and other non-steroidal anti-inflammatory drugs may be operative when patients present with haematemesis and melaena. 2. We therefore developed methods to allow separate evaluation of the erosive and anti-haemostatic actions of aspirin in the human gastric mucosa. Volunteer subjects took 300 mg of aspirin daily in the morning or 600 mg of aspirin four times a day for 5 days under blinded randomized conditions. Changes in spontaneous gastric microbleeding, endoscopic signs of injury, spontaneous bleeding per gastric erosion, biopsy-induced bleeding and eicosanoids were studied. 3. Both doses of aspirin significantly inhibited gastric mucosal synthesis of prostaglandin E2 and reduced the serum thromboxane concentration. Erosions developed and regressed rapidly; compared with baseline 300 mg of aspirin daily in the morning caused substantial numbers of gastric erosions to develop (mean 5.3, 95% confidence limits 2.7-10.2) but this was significantly less than that caused by 600 mg of aspirin four times a day (10.9, 7.2-16.5, P less than 0.05). The presence of erosions was associated with enhanced spontaneous bleeding, but only during aspirin administration. 4. Aspirin significantly increased bleeding induced by mucosal biopsy and was associated with significant enhancements in the rate of bleeding per gastric erosion. Bleeding rate per erosion but not biopsy-induced bleeding showed a significant dose-related increase with 600 mg of aspirin four times a day. Enteric coating reduced endoscopic signs of injury, but did not affect the impaired haemostasis caused by aspirin.(ABSTRACT TRUNCATED AT 250 WORDS)

Roxatidine acetate is a new histamine H2-antagonist of about twice the potency of ranitidine on a weight-for-weight basis. Two hundred and thirty-two patients participated in a double-blind randomized trial of duodenal ulcer healing comparing 300 mg ranitidine nocte with 150 mg roxatidine nocte. Endoscopy was repeated fortnightly to 4 weeks in each of four participating centres. Usual exclusion criteria applied but NSAID users were allowed. There were no important demographic differences between treatment recipients. Three analyses were used: protocol (dropouts and violators not included), intention-to-treat I (dropouts considered failures), and intention-to-treat II (dropouts considered failures, but violators outcome included). Healing rates differed markedly (but not significantly) with each analysis. After 2 weeks of treatment ulcers had healed in 51% versus 45% using the intention to treat I analysis with roxatidine and ranitidine, respectively; by the protocol analysis the healing proportions were 60% and 55%. These differences between treatments were not significant. After 4 weeks of treatment healing rates ranged from 71% to 83% on roxatidine and between 69% and 84% on ranitidine depending on the analysis. Differential healing proportions of smokers and non-smokers were non-significant (83% vs. 79%). Both drugs were well tolerated and adverse events were similar with each agent. Roxatidine should prove as effective as ranitidine for acute duodenal ulcer treatment.

A postal questionnaire inquiring about routine sedation and premedication practice for upper gastrointestinal endoscopy was sent to 1048 doctors. Of 665 appropriate returns, 81% were from consultant physicians and surgeons. Most endoscopists (90%) reported using an intravenous benzodiazepine for at least three quarters of endoscopies and 54% of physicians and 69% of surgeons always did so. Midazolam was the intravenous sedative used by a third of all respondents and 13% also used an additional intravenous agent, usually pethidine. Over the previous two years a total of 119 respiratory arrests, 37 cardiac arrests, and 52 deaths were identified. Adverse outcomes were reported more frequently by consultant physicians, by those who 'titrated' the intravenous sedative, and by those who used an additional intravenous agent, but were reported equally frequently by endoscopists using midazolam and endoscopists using diazepam. There is an urgent need for a prospective study to identify the circumstances and risk factors associated with adverse outcomes related to endoscopy.

This study investigates whether aspirin injury to the human gastric mucosa can be prevented by profound acid suppression with omeprazole, in a randomised, double blind, crossover design according to latin square. It was concluded that profound acid suppression can prevent aspirin induced gastric mucosal injury in normal subjects. This approach may prevent the development of peptic ulcers and their complications in patients taking aspirin and other non-steroidal anti-inflammatory drugs.

Objective: To evaluate the medical impact of reactive pharmacy intervention., Design: Analysis of all interventions during 28 days by all 35 pharmacists in hospitals in Nottingham., Setting: All (six) hospitals in the Nottingham health authority (a teaching district), representing 2530 mainly acute beds, 781 mental illness beds, and 633 mainly health care of the elderly beds., Patients: Hospital inpatients and outpatients., Interventions: Recording of every important intervention made by pharmacists to prescriptions for both inpatients and outpatients when they perceived inadequacies of drug prescription or administration, including characterisation of the problem, coding of outcome, recording of time taken to initiate and resolve intervention, and grade of prescribing doctor. The problems were independently assessed for their potential to cause medical harm., Results: 769 Interventions (about 2.9% of prescriptions) were made, of which 60 concerned prescriptions rated as having a major potential for medical harm. The commonest problems concerned dosage, which was wrong in 280 prescriptions (102 for antibiotics) and not stated in 50 (one for antibiotics), especially those associated with a major potential for medical harm (32 prescriptions). These concerned sedatives; analgesics; cardiovascular drugs or diuretics; and iron, vitamin, or mineral preparations. Also common were overprolonged prescription of antibiotics (48 prescriptions), confusion of drug names (nine), and inadvertent coprescription of excessive quantities of aspirin or paracetamol in plain and compound preparations (seven). The pharmacist's recommendation was accepted in 639 instances (86%), and the prescription was altered in 575, leading to an appreciable (246 cases) or minor (231 cases) improvement. Interventions had little effect on costs; 427/646 had no effect and 130 produced savings less than 50p. Pharmacy intervention (730/769 interventions) occupied on average 41 minutes per pharmacist per week., Conclusions: Most reactive pharmacy interventions concerned prescribing errors with a limited potential for medical harm, but a small number of detected errors with a major potential for medical harm; cost savings were not appreciable.

To assess the effect of indomethacin on gastric acidity and to identify a potential pharmacodynamic interaction between indomethacin and ranitidine, we measured nocturnal acidity on half-hourly aliquots of gastric contents from 10 volunteers on the seventh day of four dosing regimens given in a randomized double-blind manner. These were indomethacin (50 mg t.d.s.) and ranitidine (300 mg in the evening) together or alone with matching placebos. Median nocturnal acidity on placebo was 41.7 mmol/L (range 67.6-25.1 mmol/L) and was 39.8 mmol/L (63.1-24.0 mmol/L) on indomethacin (N.S.). During ranitidine dosing it was 0.4 mmol/L (21.3-0.0 mmol/L) without and 0.8 mmol/L (43.7-0.0 mmol/L) with concurrent indomethacin, representing 99 and 98% decreases in gastric acidity (P less than 0.01) compared with placebo. Indomethacin did not increase overnight gastric acidity and did not influence the suppression of acidity produced by ranitidine. It is unlikely that the ulcerogenic potential of indomethacin is explicable by an effect on gastric acidity.

Ketoconazole pharmacokinetics were determined in nine adults with haematological malignancy after one week on a 200 mg daily dose and later after one week on a 400 mg daily dose. The area under the serum concentration time curve (AUC) reached 12.3 +/- 7.7 mg/l.h (mean +/- S.D.) on the 200 mg dose and increased to 23.0 +/- 18.2 mg/l.h on the 400 mg dose (p less than 0.05). The half-life of ketoconazole was 3.1 +/- 1.9 h on the 200 mg dose and 3.5 +/- 1.7 h on the 400 mg dose. Peak concentrations were 3.2 +/- 1.8 mg/l and 4.6 +/- 3.2 mg/l on the 200 mg and 400 mg doses, respectively. Trough ketoconazole concentrations were undetectable 24 h after either dose. There was no correlation between the leucocyte count and any pharmacokinetic parameter for ketoconazole. Variation in AUC was 20-fold on the 200 mg daily dose and 8-fold on the 400 mg per day regimen. Measurement of serum levels during ketoconazole treatment appears necessary in view of the unpredictable concentrations achieved. Once-a-day dosage regimens of ketoconazole in immunocompromised patients may be inappropriate. Future clinical trials should adopt a two or three times a day dosing regimen, as this may confer a pharmacokinetic and therapeutic advantage.

Eight healthy adults were given single oral doses of ketoconazole (200, 400, 600, and 800 mg) in the fasting state and with a standard breakfast at weekly intervals according to a balanced block design. Concentrations in serum were measured up to 32 h after the dose. Food did not reduce ketoconazole absorption or significantly alter peak ketoconazole concentrations in serum, though there was a food-related delay in achieving peak concentrations. At the 400- and 600-mg doses, food appeared to enhance absorption, but this effect was not seen at the 800-mg dose. With an increase in dose, the half-life and area under the serum concentration-time curve increased disproportionately, suggesting that the pharmacokinetics of ketoconazole may be dose dependent. Up to the 800-mg dose, the elimination of ketoconazole did not appear to be saturable. Administration of the drug with food is unlikely to be a cause of therapeutic failure.

We report a case of phenytoin-associated Hodgkin's disease of lymphocyte predominance subtype, which developed after two years of phenytoin (Epanutin) treatment. Four other English cases of phenytoin-associated lmphoid malignancy are also reviewed.

The effects of three beta blockers on liver blood flow and hepatic enzyme activity were investigated. Eight healthy subjects received placebo, 100 mg metoprolol, 40 mg nadolol, and 60 mg propranolol orally three times a day for four days in a randomized block design. On the fourth day of each treatment, beta blockade was measured by inhibition of exercise-induced tachycardia and apparent liver blood flow was measured by indocyanine green clearance. Plasma concentrations of the beta blockers were measured 2 hours after the early morning dose. Metoprolol produced the greatest inhibition of exercise tachycardia. All three drugs appeared to reduce liver blood flow, but this was only statistically significant in the case of propranolol. Enzyme inhibition occurred but to a varying extent. Propranolol produced a 36 per cent fall in antipyrine clearance (P less than 0.1) while metoprolol and nadolol both caused a 12 per cent reduction (P less than 0.05 and P = 0.06, respectively). Wide interindividual variation in the plasma concentrations of the drugs limit interpretation, but the results suggest that at the doses used, metoprolol and nadolol may be less likely to cause significant drug interaction by enzyme inhibition than propranolol.

Two studies were conducted on indenolol, a new beta-adrenoceptor blocker. In the first, nine healthy men received indenolol 40, 80, 160, and 320 mg and placebo orally. Two hours later a standard exercise test was performed, and systolic blood pressure, heart rate, and peak expiratory flow rate were recorded. Indenolol induced attenuation of exercise-induced rise in systolic blood pressure and tachycardia. In the second study, seven healthy men received indenolol 40, 80, 160, and 320 mg and propranolol 40, 80, 160, and 320 mg in randomized order. Dose-response curves for both drugs revealed that maximum attenuation of exercise tachycardia and systolic blood pressure were in the same range but suggested that indenolol induced a greater response in the lower doses. Neither drug had any effect on the exercise-induced rise in peak expiratory flow rate. Indenolol was well tolerated.

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.

Ketoconazole 200 mg was given twice daily for five days to eight subjects. The serum pharmacokinetics were examined with the first dose on day 1 and with the ninth dose on day 5. The serum half life of ketoconazole was 74.8 +/- 13.9 min (mean +/- S.D.) on day 1, and 155.9 +/- 32.7 min on day 5. On day 1 the area under the serum concentration time curve was 626.9 +/- 230.1 mg/l.min, and 1441 +/- 897.3 mg/l.min on day 5. Antipyrine kinetics were determined before and after the course of ketoconazole. There was no significant change in the clearance and half life of antipyrine. Ketoconazole in the doses used in this study does not appear to alter hepatic microsomal enzyme activity in man. The increased ketoconazole half life and area under the serum concentration time curve on day 5 were in part caused by food. Other mechanisms for these changes such as saturation of a tissue compartment or a change in the elimination of ketoconazole during chronic dosing, may also be responsible.

Oxamniquine pharmacokinetics were determined in five normal Sudanese subjects and nine Sudanese patients with advanced hepatosplenic schistosomiasis, given 1 g as a single oral dose. There were no significant differences in oxamniquine mean area under the plasma concentration time curve (AUC), plasma half life (T1/2), or time to reach peak concentration (Tmax). However, patients had a 19% lower mean AUC, a 36% higher T1/2, and a 23% increase in Tmax. The peak concentration (Cmax) was 36% lower in patients (P = 0.04). There was no correlation between disease severity and oxamniquine pharmacokinetic values. A significant correlation between oxamniquine AUC and T1/2 suggests that its elimination may be non-linear. The higher dosage requirements for oxamniquine in the Sudan are unlikely to be due to lower plasma concentrations amongst the Sudanese.