Effect of nevirapine, efavirenz and lopinavir/ritonavir on the therapeutic concentration and toxicity of lumefantrine in people living with HIV at Lagos University Teaching Hospital, Nigeria

Patients living with HIV in malarial endemic regions may experience clinically significant drug interaction between antiretroviral and antimalarial drugs. Effects of nevirapine (NVP), efavirenz (EFV) and lopinavir/ritonavir (LPVr) on lumefantrine (LM) therapeutic concentrations and toxicity were evaluated. In a four-arm parallel study design, the blood samples of 40 participants, treated with artemether/lumefantrine (AL), were analysed. Lumefantrine Cmax was increased by 32% (p = 0.012) and 325% (p < 0.0001) in the NVP and LPVr arms respectively but decreased by 62% (p < 0.0001) in the EFV-arm. AUC of LM was, respectively, increased by 50% (p = 0.27) and 328% (p < 0.0001) in the NVP and LPVr arms but decreased in the EFV-arm by 30% (p = 0.019). Median day 7 LM concentration was less than 280 ng/mL in EFV-arm (239 ng/mL) but higher in control (290 ng/mL), NVP (369 ng/mL, p = 0.004) and LPVr (1331 ng/mL, p < 0.0001) arms. There were no clinically relevant toxicities nor adverse events in both control and test arms. Artemether/lumefantrine is safe and effective for treatment of malaria in PLWHA taking NVP and LPVr based ART regimen but not EFV-based regimen.

Novel action of vinpocetine in the prevention of paraquat-induced parkinsonism in mice: involvement of oxidative stress and neuroinflammation

Parkinson's disease (PD) is a multifactorial chronic progressive neurodegenerative disease caused by age, genetic and environmental factors such as paraquat (PQT). PQT (a quartenary nitrogen herbicide) is implicated in some form of idiopathic PD. This study sought to investigate the protective effect of vinpocetine on paraquat-induced Parkinsonism in mice. Forty-eight male albino mice were randomly divided into 6 groups and treated orally as follows for 21 days; Group 1: vehicle normal (10 ml/kg), group 2: vehicle control (10 ml/kg); groups 3-5: vinpocetine (5, 10 or 20 mg/kg); group 6: vinpocetine (20 mg/kg). Animals in groups 2-5 were given PQT (10 mg/kg, i.p.) every 3 days for 3 weeks. The effect of treatments on spontaneous motor activity (open field test), muscle coordination (rotarod tests), cataleptic behaviour (bar test), and working memory (Y-maze test) were assayed. After the behavioural assay on day 21, the midbrain was isolated for estimation of oxidative stress and TNF-α. Intraperitoneal injection of paraquat significantly induced motor deficits, muscle incoordination, catalepsy and working memory impairment which was ameliorated by the pretreatment of mice with vinpocetine. In addition, paraquat injection caused marked increase in nitroso-oxidative stress markers with concomitant deficits in antioxidant enzymes activities (GSH and SOD) as well as induction of tumour necrotic factor-α (TNF-α) in the mid-brain which were attenuated by the pretreatment of mice with vinpocetine. Findings from this study showed that vinpocetine prevented paraquat-induced motor deficits, memory impairment, oxidative stress and neuroinflammation through enhancement of antioxidant defense system and inhibition of neuroinflammatory cytokine. Thus, could be a potential drug in the management of Parkinsonism.

How do we prevent the burden of extremely harmful and clinically nonbeneficial drug–drug interactions among chronic kidney disease patients?

The chronic intake of different medications by chronic kidney disease (CKD) patients predisposes them to extremely harmful and clinically nonbeneficial drug–drug interactions (DDIs) which can ultimately lead to increase in morbidity, mortality, healthcare cost, and frequency and length of hospitalization. This produces a negative deteriorating and counter-efficient outcome on the health, quality of life and treatment response of these patients. This was an 18-month prospective descriptive study that reviewed the medical case records of consented adult CKD patients attending the Nephrology medical outpatient clinic of a Nigerian Tertiary Healthcare Centre from January 2015 to June 2016. The Medscape drug reference database was used to evaluate patients’ medications for extremely harmful, clinically nonbeneficial DDIs. This study involved 123 consented adult CKD patients comprising of 82 (66.67%) males and 41 (33.33%) females with a mean age of 53.81 ± 16.03 years. In this study, the prevalence of extremely harmful, clinically nonbeneficial DDIs (type D or type X interaction categories only) was 24.4%, while the overall prevalence for all the observed DDIs was 95.9%. The most frequent extremely harmful, clinically nonbeneficial DDIs in this study was between α-methyldopa and metoclopramide: 16 (0.9%) interactions in eight (6.5%) patients. Furthermore, α-methyldopa decreases the antiemetic effects of metoclopramide by pharmacodynamics antagonism at the chemoreceptor trigger zone site D2-receptors (type X; pharmacodynamics). In addition, metoclopramide decreases the level of α-methyldopa by inhibition of gastrointestinal tract (GIT) absorption, as this applies to only oral formulations of both agents (type D; pharmacokinetic). The occurrence and burden of extremely harmful, clinically nonbeneficial DDIs is significantly high among these CKD patients. There is also a critical need to minimize the number of prescribed medications for these patients in order to optimize their care.

Biochemical, hematological, and hormonal profile of rats orally administered methanol stem bark extract of Napoleona vogelii Hook and Planch (Lecythidaceae)

Napoleona vogelii is used in traditional medicine for the management of stomach aches, ulcer, and cancers. This study was conducted to investigate the subchronic toxicological effect of methanol stem bark extract of N. vogelii on biochemical, hematological, and hormonal profile of male and female rats. Forty rats of both sexes were randomly divided into four groups of 10 rats each and were administered 100, 200, and 400 mg/kg of the extract p.o. for 90 d. Ten milliliter per kilogram of distilled water p.o. was administered to control rats. On hematological assessment, mean corpuscular hemoglobin concentration was significantly (p < 0.01) increased at 400 mg/kg compared to control. Biochemical assessment showed a significant increase (p < 0.05) in levels of alanine aminotransferase and aspartate aminotransferase at 200 and 400 mg/kg, respectively, compared to control. Hormonal assessment of male rats revealed a significantly (p < 0.0001) reduced level of testosterone at all treatment doses compared to control while estradiol was significantly (p < 0.05) reduced at 100 mg/kg, but significantly (p < 0.0001) increased at 200 and 400 mg/kg respectively compared to control in female rats. Findings from this study demonstrate that N. vogelli is relatively safe on oral acute exposure but may possess the potential to cause hepatic dysfunction and infertility in male rats by perturbations of the hypothalamic-pituitary axis while conversely enhancing fertility in female rats on subchronic administration.

Hepatoprotective and antioxidant activities of Hepacare®, a herbal formulation against carbon tetrachloride-induced liver injury

BACKGROUND

Hepacare(®) is a herbal formulation used to treat patients with sickle-cell anaemia complicated with jaundice, also recommended as a protective agent against liver damage due to chronic ingestion of alcohol.

METHODS

In vitro antioxidant properties of Hepacare(®) was determined using 1, 1- diphenyl-2-picryl-hydrazyl (DPPH), total antioxidant capacity, reducing power ability, and nitric oxide assays. Hepatoprotective effect of Hepacare(®) (50-400 mg/kg/day for 7 days, p.o.) was investigated in male Sprague Dawley rats against carbon tetrachloride (CCl(4) /olive oil, 1:1, 0.7 ml/kg, i.p.)-induced liver damage. At the end of the study, blood samples and liver tissue were assayed for biochemical and antioxidants parameters.

RESULTS

Hepacare produced concentration dependent inhibition of DPPH and nitric oxide activity with IC(50) of 48.50 and 55.00 µg/ml, respectively, it suppressed the absorbance of ABTS(.+) with total antioxidant capacity of 423.47±8.37 mg QUE/g. CCl(4) administration induced significant (P<0.001) elevation of serum aspartate transaminase (1.70 fold), alanine transaminase (1.60 fold), alkaline phosphatase (2.90 fold) and bilirubin (2.00 fold) in comparison to control. The increase in serum biomarker were dose-depen-dently reversed by Hepacare(®) pretreatment. More-over, CCl(4) pretreatment increased (P<0.001) malondialdehyde (MDA) (73.98%) and decreased (P<0.001) antioxidant enzymes level but Hepacare pretreatment produced dose-dependent attenuation of the increased MDA (3.84 fold) with enhancement of glutathione (3.08 fold), superoxide dismutase (2.08 fold), and catalase (3.14 folds) levels in comparison to CCl(4) treated group, similar to those of silymarin reference standard.

CONCLUSION

Hepacare was beneficial in the prevention of CCl(4)-induced hepatocellular injury, possibly by scavenging reactive free radicals, and boosting endogenous antioxidant systems.

Antidepressant and anxiolytic properties of the methanolic extract of Momordica charantia Linn (Cucurbitaceae) and its mechanism of action

BACKGROUND

The whole plant of Momordica charantia Linn (Cucurbitaceae) is used in traditional African medicine in the management of depressive illness.

METHODS

Momordica charantia (MC) (50-400 mg/kg, p.o.) was administered 1 h before behavioural studies using the forced swimming test (FST) and tail suspension test (TST) to investigate antidepressant-like effect while the anxiolytic-like effect was evaluated with elevated plus maze test (EPM), hole-board test (HBT), and light-dark test (LDT).

RESULTS

Acute treatment with MC (50-400 mg/kg) significantly increased swimming time (86.51%) and reduced the duration of immobility (52.35%) in FST and TST with peak effects observed at 200 mg/kg, respectively, in comparison to control. The pretreatment of mice with either sulpiride (dopamine D2 receptor antagonist), or metergoline (5-HT2 receptor antagonist), or cyproheptadine (5-HT2 receptor antagonist), or prazosin (α1-adrenoceptor antagonist), or yohimbine (α2-adrenoceptor antagonist), and atropine (muscarinic cholinergic receptor antagonist) 15 min before oral administration of MC (200 mg/kg) significantly blocked its anti-immobility effect. Similarly, MC (200 mg/kg) significantly reduced anxiety by increasing the open arm exploration (64.27%) in EPM, number of head-dips in HBT (34.38%), and time spent in light compartment (29.38%) in the LDT. However, pretreatment with flumazenil (GABAA receptor antagonist) 15 min before MC (200 mg/kg) significantly blocked (54.76%) its anxiolytic effect.

CONCLUSION

The findings in this study showed that MC possesses antidepressant-like effect that is dependent on the serotonergic (5-HT2 receptor), noradrenergic (α1- and α2-adrenoceptors), dopaminergic (D2 receptor), and muscarinic cholinergic systems and an anxiolytic-like effect that might involve an action on benzodiazepine-type receptor.

The use of artemisinin-based combination therapies (ACTs) in public secondary health facilities in Lagos, Nigeria

OBJECTIVES

The objectives of the study were to assess the prescription pattern of Artemisinin Combination Therapies (ACTs) in uncomplicated malaria and the knowledge, attitude and practice of physicians as regards use of ACTs in the outpatient clinics of public secondary health facilities in Lagos State.

PATIENTS AND METHODS

All the ten General Hospitals under the Lagos State Health Management Board were studied and classified as either rural or urban. 1878 retrospective antimalarial prescriptions of outpatients between March, 2005--March, 2006 were systematically sampled and questionnaires were distributed to prescribers in April--May, 2006. Prescription assessment was based on the recent Nigerian National Antimalarial Treatment Policy and WHO/INRUD drug use indicators.

RESULTS

The percentage of prescriptions containing ACTs was found to be rather small (5.9%) inspite of the high proportion (59.2%) of prescribers who were favourably disposed to the National antimalarial policy change from Chloroquine to ACTs as first line. There was no statistically significant difference in frequency of ACTs prescription between the rural and urban health facilities. The prescription of Artemisinin derivatives as monotherapy was 18.2%. The prescription of Chloroquine was found to be more predominant, (48.8%) in all the health facilities.

CONCLUSION

Despite the national policy change from Chloroquine to (ACTs) as the first line antimalarial, their use in the public secondary health facilities in Lagos State does not reflect this policy change and it appears that Chloroquine still remains the choice antimalarial drug.

Prescription pattern at primary health care centres in Lagos State

Health care received in health facilities depends on adequate consultation, correct prescription and dispensing with relevant information given to the patient. These are some of the indicators for rational drug use. The objective of the study was to determine the pattern of prescription among prescribers in twenty Primary Health Care Centers of Lagos State using some of these indicators used in investigating health facilities by the World Health Organisation and International Network for Rational Use of Drugs. The study was carried out using multi-stage random sampling in selecting the Primary Health Care Centers from each of the twenty Local Government Areas of Lagos State. Both prospective and retrospective data were collected and analysed using Epi-Info version 6. The results showed that there was polypharmacy, misuse of antibiotics and injections. There was no statistically significant difference between the retrospective and prospective indicators of mean drugs prescribed per encounter, percentage antibiotics prescribed and percentage of generic prescription. It was concluded that there was irrational prescription pattern in all the selected health facilities as evidenced by poly-pharmacy, misuse of antibiotics and low generic prescriptions. There is need for educational intervention to improve the prescribing habits of health professionals in these health facilities.