Biomedical subjects

A Sowunmi

Publications and source records attributed to A Sowunmi.

At least 73 records · Page 4Linked to original sources

PubMed1996

Amlodipine as monotherapy in hypertensive Africans: clinical efficacy and safety studies.

Amlodipine as a monotherapy was evaluated in 20 patients with mild, moderate, and severe hypertension over a 10 week period. After a washout period of 4 weeks, Amlodipine was administered at a dose of 5 mg once daily for 2 weeks and increased to 10 mg once daily if diastolic blood pressure did not fall to below 90 mmHg. At the end of the trial, diastolic blood pressure was reduced to below 90 mmHg in all but four patients. However, these four patients had greater than 20 mmHg reduction in diastolic blood pressure. There was a slight, but insignificant increase in heart rate. Dizziness and weakness occurred in one patient, otherwise, the drug was well tolerated. Laboratory tests, including plasma lipids done at the start and end of the trial, remained unchanged.

Aged↗

PubMed1996

Disposition of quinine in plasma after a single oral and intramuscular dose in healthy adult Africans.

The pharmacokinetics of quinine were assessed in healthy adult Africans after a single oral dose of 500 mg quinine base (n = 11) and after a single intramuscular injection of 500 mg quinine base (n = 7). Quinine was assayed in plasma by high performance liquid chromatographic method (HPLC). Quinine was rapidly absorbed reaching a mean peak concentrations of 2.9 (sd 0.5) and 4.5 (1.3) mg L-1 respectively in a median time of 3.0 (range 2.0-4.0) and 1.5 (range 0.5 4.0) h respectively after oral and intramuscular administration. The peak concentration (Cmax) was significantly higher after intramuscular than after oral administration [Cmax = 4.5 (1.3) versus 2.9 (0.5) mg L-1, p < 0.01]. The mean half-life [t1/2z = 11.7 (2.9) versus 10.7 (3.5) h, P > 0.2] respectively, volume of distribution (Vz = 2.5 (0.7) versus 2.2 (0.99) L Kg-1, P > 0.2) respectively and estimated plasma clearance [CLp = 0.15 (0.04) versus 0.15 (0.09) L h-1 Kg-1, P > 0.2] respectively were not significantly different after oral and intramuscular administration. The mean AUCo-oo was higher after intramuscular than after oral administration [71.8 (29.4) versus 54.9 (19.2) mg.h.L, P > 0.1] respectively but this was not significant. The pharmacokinetic parameters after intramuscular dose were similar to those obtained in seven healthy subjects given quinine by slow intravenous infections over four hours. The dose was well tolerated.

Administration, Oral↗

PubMed1996

Disposition of oral quinine in African patients suffering from acute uncomplicated falciparum malaria.

Plasma concentrations of quinine following oral administration of 10mg/kg of body weight quinine hydrochloride were measured by HPLC in eleven African patients during acute symptomatic uncomplicated Plasmodium falciparum malaria and after complete recovery from the acute illness. Following a single oral dose, mean plasma quinine concentrations were significantly higher during the acute illness than after recovery (5.2 +/- 0.9 ug/ml versus 3.6 +/- 0.4 ug/ml). The mean time to peak plasma concentration was 3.9 +/- 09 hour during the acute illness and 1.8 +/- 0.9 hour after convalescence. The apparent oral clearance was significantly lower during the acute illness than after recovery. The volume of distribution was 3.0 +/- 0.3 L/kg during the acute illness and 4.9 +/- 1.4 L/kg after convalescence. Following multiple dosing, the mean minimum pre-dose plasma quinine concentration was obtained on the second day of treatment and the mean maximum three-hour post dose plasma quinine concentration occurred on the third day of treatment. The decline in plasma concentration following multiple dosing was monoexponential with a terminal half-life of 12.1 hours. There was no relationship between pharmacokinetic parameters and parasite or fever clearance times. There was no serious toxicity during therapy. In all patients, parasitaemia cleared within 72 hours. These data would suggest that the disposition of quinine is significantly altered by acute falciparum malaria; the high plasma quinine concentration following oral administration during acute infection may be related to a lower apparent volume of distribution and a reduced systemic clearance.

Acute Disease↗

PubMed1996

Biochemical changes during a cross-over treatment of doxazosin, moduretic and amlodipine in hypertensive patients.

A cross-over study was done to compare the effects of doxazosin, moduretic and amlodipine on biochemical values in 9 hypertensive Nigerians aged 35 to 65 years. Doxazosin therapy was characterized by significant increase in the levels of mean plasma total protein and albumin, while moduretic therapy showed significant reduction in the mean values of plasma creatinine and calcium. All other parameters did not show any significant variation during doxazosin and moduretic treatment phases; and amlodipine therapy did not have any effect on the biochemical values of the hypertensive patients.

Adult↗

PubMed1996

Hyponatraemia in severe falciparum malaria: a clinical study of nineteen comatose African children.

In a prospective study, hyponatraemia was observed in 52.6% of 19 children with cerebral malaria on admission, the plasma sodium ranging from 117 to 129 mumol/l. In addition, a further 10% developed hyponatraemia between 48 and 96 hrs after admission; in half of these, there was continuing urinary sodium loss. The clinical presentation of hypo- and normonatraemic children was similar except for vomiting and hypoglycaemia which were commoner in the normonatraemic and irritability and signs of lower respiratory tract infection which were commoner in the hyponatraemic groups. In hyponatraemic and normonatraemic children, there was a negative correlation between hyponatraemia and parasite density (r = -0.503, P < 0.05) and (r = -0.14, P < 0.05 respectively) and between parasite density and urinary sodium concentration during the first 24 hours of admission (r = -0.034; P < 0.05 and r = -0.045, P > 0.05 respectively). Irrespective of group, a relative increase in plasma sodium in the first 24 hours of admission (positive delta Na 24 h) was associated with a reduction in seizure frequency during this period as compared to the reported 24 hour of pre-admission seizure frequency, and, vice-versa. It is concluded that hyponatraemia is not uncommon in childhood cerebral malaria; urinary sodium loss may be contributory to the hyponatraemia seen in this condition.

Child, Preschool↗

PubMed1996

Open trial of doxazosin in hypertensive Africans: dose finding, efficacy and safety studies.

Doxazosin, as a mono-therapy, was studied in 28 patients with mild to severe hypertension over a period of 8 weeks. After a wash-out period of 2 weeks, doxazosin was started at a dose of 1 mg daily and increased gradually until the diastolic blood pressure fell to below 90 mm Hg or a maximum dose of 16 mg daily was reduced. Forty-three percent of the patients had good response with diastolic blood pressure falling to normal (< 90 mm Hg) or by more than 10 mm Hg whilst 68% of the patients had a reduction of greater than 5 mm Hg. Doxazosin reduced blood pressure without significant increase in heart rate and was, overall, well tolerated producing mild side effects not requiring withdrawal, or reduction in dosage of the drug in 6 cases. The effect of doxazosin on lipids showed a trend towards reduction of total cholesterol and increase in HDL, but these data need confirmation in a longer study in a larger population sample.

Adult↗

PubMed1995

Body temperature and malaria parasitaemia in rural African children.

Body temperature was measured and the prevalence of malaria parasitaemia was determined in 198 rural school children aged 6-12 years in a hyperendemic area of southwest Nigeria over a 14 week period spanning part of both wet and dry seasons. Body temperature values in apparently healthy children and in children with malaria parasitaemia were similar with group mean of 37.1 to 37.3 degrees C and with little or no variation in these values with season. The proportion of individual measurements with values > 37.5 degrees C in the two groups were respectively 4.3 and 6%. Despite a seasonal variation in parasite rate, with the highest rates in the wet and the lowest rates in the dry season, there was no significant difference in the proportion of subjects with parasite density > 1000/ul between season. There was also no relationship between parasite density and body temperature. In general, children with parasitaemia < 1000/ul were not pyrexial and less than 2% of all episodes of detectable parasitaemia was accompanied by symptoms of acute malaria. These findings suggest that the presence of malaria parasitaemia has little or no effect on body temperature pattern in a group of rural school children in an endemic area.

Body Temperature↗

PubMed1995

Falciparum malaria presenting as psychosis.

A 15-year-old male presented on three occasions with fever, aggressive behaviour, poor sleep and mixed affective and schizophreniform symptoms in association with falciparum malaria. The symptoms resolved promptly following anti-malarial treatment. Prophylaxis with proguanil prevented recurrence of the illness.

Adolescent↗

PubMed1995

Acute psychosis after mefloquine. Report of six cases.

A self-limiting psychosis characterized by acute onset of visual and auditory hallucinations and poor sleep developed in six adults between 8 and 24 hours after oral administration of 750-1500 mg of the antimalarial mefloquine. All patients had no personal or family history of psychosis and were neurologically and mentally normal before mefloquine ingestion. These cases illustrate that acute psychotic symptoms may occur in patients treated with mefloquine.

Acute Disease↗

PubMed1995

[NANP]19-5.1. A malaria vaccine field trial in Nigerian children.

[NANP]19-5.1 is a recombinant Plasmodium falciparum vaccine consisting of 19 repeats of the sporozoite surface protein [NANP] and the schizont export antigen 5.1. In a previous study, an experimentally infected subject (with a history of malaria exposure and an elevated pre-immunization lymphocyte stimulation index to antigen 5.1) showed parasitaemia but no signs of clinical malaria. In an attempt to find a comparable partially immune population, we tested the vaccine in 194 schoolchildren (6 to 12 years, vaccine and placebo groups of equal size), who already possessed a certain degree of immunity. It was hoped that this immunity would be boosted by the vaccine. During the 12 weeks of observation, no child developed clinical malaria. Analysis of serum taken before and after immunization revealed that, except for eight children, all had considerable levels of antibodies to both antigens. We conclude that the trial should be repeated in younger children who are still vulnerable to clinical malaria.

Animals↗

PubMed1995

Leukocyte counts in falciparum malaria in African children from an endemic area.

Total leukocyte counts were done in 180 apparently healthy rural school children aged 6-12 years in a malaria endemic area in southwestern Nigeria. Total leukocyte counts and their distribution in aparasitaemic and asymptomatic parasitaemic children were similar. Total leukocyte counts, and the relationship between the density of parasitaemic and total leukocyte counts were studied in 55 consecutive children presenting with acute symptomatic falciparum malaria. Children without parasitaemia were older and had lower total leukocyte counts when compared with children with parasitaemia (7.61 +/- 4.11 x 10(9)/L Vs 9.04 +/- 5.0 x 10(9)/L), but the difference was not statistically significant (P > 0.05). In non-hyperparasitaemic children and in hyperparasitaemic children with percentage infected red cells < 10%, there was poor correlation between density of parasitaemia and total leukocyte counts. However, at > or = 10% parasitaemia, there was a positive correlation (r = 0.55; P = 0.032) between increasing parasitaemia and leukocytosis. Combination of hyperparasitaemia ( > 5% parasitaemia) and leukocytosis ( > 12 x 10(9)/L) occurred in 15% of the children and was not a poor prognostic index in the absence of other evidence of severe or complicated disease, as response to oral mefloquine was prompt. This would suggest that in African children from an endemic area, this combination is not a reliable indicator of severity or poor prognosis in falciparum malaria.

Acute Disease↗

PubMed1995

Ethnic differences in nifedipine kinetics: comparisons between Nigerians, Caucasians and South Asians.

Nifedipine was administered to 12 healthy Nigerian volunteers as a single oral dose of 20 mg capsule under fasting conditions. The pharmacokinetic results were compared with published data using the same protocol and analytical method for 27 Caucasians and 30 South Asians. The area under the plasma concentration-time curve (AUC) of nifedipine in Nigerians (808 +/- 250 ng ml-1 h) was significantly higher (P < 0.001) than that in Caucasians (323 +/- 116 ng ml-1 h) and the difference remained significant (P < 0.001) when corrected for body weight. The elimination half-life was also significantly higher (P < 0.01) in Nigerians (5.03 +/- 1.96 h) than in Caucasians (2.78 +/- 1.11 h). No significant differences were observed between Nigerians and South Asians in either AUC or half-life of nifedipine. The AUC of the nitropyridine metabolite was higher (P < 0.01) in Nigerians (220 +/- 51 ng ml-1 h) compared with that in Caucasians (154 +/- 56 ng ml-1 h) but the difference was not maintained when corrected for body weight. The AUC corrected for body weight and the elimination half-life of the metabolite were significantly higher in South Asians compared with those of Nigerians and Caucasians. The pharmacokinetics of oral nifedipine in Nigerians were similar to those in South Asians and therefore may also arise from a lower systemic clearance compared with Caucasians as has been reported previously for South Asians.

Adolescent↗

PubMed1994

Artemether in moderately severe and cerebral malaria in Nigerian children.

Intramuscular artemether was compared with intramuscular sulfadoxine-pyrimethamine in Nigerian children with moderately severe malaria requiring parenteral therapy. Artemether produced significantly shorter parasite and fever clearance times but a higher parasite recrudescence rate than sulfadoxine-pyrimethamine. There was no significant difference in their initial parasitological cure rates--100% for artemether, 98% for sulfadoxine-pyrimethamine. In a separate study intramuscular artemether was compared with intravenous quinine in children with cerebral malaria. There was no significant difference between the 2 drugs in parasite and fever clearance times, time to regain consciousness, or recrudescence rate. There was an overall mortality of 16.7%, with 12% in the artemether group and 21% in the quinine group. Artemether was well tolerated. There was no abnormal change in haematological and biochemical features monitored and there was no adverse clinical reaction. These results show that artemether is a potentially useful drug for moderate and severe malaria and its place in the chemotherapy of malaria deserves further study.

Antimalarials↗

PubMed1994

Brain swelling and ischaemia in Kenyans with cerebral malaria.

Computed tomography was performed on 14 unconscious Kenyan children recovering from cerebral malaria (seven of whom had another scan 12-120 days later) to elucidate the cause of intracranial hypertension and neurological sequelae. Brain swelling, defined as a loss of cerebrospinal fluid spaces, was documented in six children, while a further two had conspicuously small ventricles only. There was severe intracranial hypertension in the two children with definite brain swelling in whom intracranial pressure was monitored. There was no evidence of acute hydrocephalus or vasogenic oedema. Four children with brain swelling also had widespread low density areas suggestive of ischaemic damage. The patterns of damage were not uniform but were consistent with a critical reduction in cerebral perfusion pressure (which was documented in the two in whom this was monitored), hypoglycaemia, or status epilepticus. All four had serious neurological sequelae. These data suggest that brain injury in cerebral malaria may be due in part to secondary systemic and intracranial factors as well as to the direct effect of intravascular sequestration.

Brain↗

PubMed1994

Bioavailability of sulphate and dihydrochloride salts of quinine.

A comparative bioavailability of three formulations of quinine was performed in 6 healthy male adult Africans after intravenous infusion of 600mg quinine hydrochloride in 0.9% saline over 4 hours and after single oral doses of 600mg quinine sulphate capsule, 600mg quinine dihydrochloride plain tablet and 600mg quinine sulphate sugar coated tablet. The drugs were given according to a randomised cross-over design. The quinine sulphate coated tablet was found to contain no quinine. There was no statistical significant difference (P > 0.05) in the plasma Cmax, tmax, AUC and Ka values between the quinine sulphate capsule and quinine dihydrochloride plain tablet, although a considerable degree of inter- and intra-individual variability in the pharmacokinetic parameters was observed. The absolute bioavailability was 64.5 and 64.3% for the quinine sulphate capsule and the quinine dihydrochloride plain tablet respectively. The non-detection of quinine in the sugar coated tablet (obtained from Nigeria) confirms the presence of fake circulating antimalarial drugs in the country.

Administration, Oral↗

PubMed1994

Acute psychosis after mefloquine: a case report.

A self-limiting psychosis characterized by visual and auditory hallucinations and isomnia occurred in a 17-year old male after mefloquine administration for presumed chloroquine resistant falciparum malaria. The attending physician failed to recognise the association between mefloquine and psychosis.

Adolescent↗

PubMed1994

Biochemical changes during amlodipine treatment in hypertensive patients.

Twenty adult hypertensive patients mean age (52 (1.73) y) were treated with amlodipine 5 mg (8 patients) and 10 mg (12 patients) once daily for 12 weeks. There was a reduction in sitting and standing diastolic and systolic blood pressures in male and female patients. Plasma calcium, sodium, potassium, total proteins, albumin, globulins, phosphate, chloride, urea and haematological parameters were not significantly altered by amlodipine therapy in any patient. An increase in creatinine level was noted, which was not related to kidney dysfunction. We conclude that amlodipine 5 mg or 10 mg once daily is effective in male and female patients, and it does not alter biochemical and haematological values in hypertensive African patients.

Amlodipine↗

PubMed1993

Congenital malaria in a hyperendemic area: a preliminary study.

The prevalence of Plasmodium falciparum parasitaemia was evaluated in 59 neonates admitted to the University College Hospital, Ibadan in South-western Nigeria between August and December 1991--a period spanning part of both wet and dry seasons. Peripheral parasitaemia was present in 14 (23.7%) neonates; of these, four were preterm (4/26, 15%) and ten were term babies (10/33, 30.3%). The difference in the prevalence of P. falciparum parasitaemia in the two groups was not statistically significant (chi 2 = 1.78; p = 0.10). Parasite densities in all neonates were uniformly low (< 2000 asexual forms/microliters blood), and only four of the neonates had fever within 48 hrs of birth. Infected neonates weighed 200 g more than non-infected neonates, but the difference was not statistically significant. Maternal weekly pyrimethamine prophylaxis did not appear to be effective in preventing infection as six (21.4%) of the 28 neonates whose mothers had regular prophylaxis had parasitaemia compared with seven (26.9%) of the 26 neonates whose mothers had no prophylaxis (chi 2 = 0.22; p > 0.05). These data indicate that congenital malaria is not as uncommon as was previously thought and that the recent increase in reported cases may be due to an interplay of several factors.

Chloroquine↗