[Clinical trials in Dakar: survey on knowledge, attitudes and practices of key actors on the period from 2003 to 2007]. / Essais cliniques à Dakar: enquête sur les connaissances, attitudes et pratiques des principaux acteurs sur une période allant de 2003 à 2007.

AIM: The general objective of this study was to agree an inventory of fixtures of clinical trials done in Dakar, in order to make recommendations to improve the quality of clinical trials in Senegal. METHOD: We have done a survey from mars to may 2007, with investigators of the two biggest Senegalese university teaching hospitals and to the pharmacy management and the ethical committee. RESULTS: Our key results showed: 1) a small participation rate of teachers to clinical trials (11 on 37 interviewed); 2) that the principal sponsor is pharmaceutical industry; 3) that most of investigators have not degree in clinical trials; 4) that most pathologies concerned were malaria and AIDS; 5) that there are regulations related to clinical trials in Senegal. CONCLUSION: This study shows the necessity to integrate, in Senegal, clinical trials in the curricula of students training.

Medicinal plants and the treatment of diabetes in Senegal: survey with patients.

Diabetes is the most common metabolic disorder worldwide and is a major public health problem. Its frequency increases every day in all countries. However, in developing African countries, few people have access to drugs. In addition, in Africa, traditional beliefs induce people to use medicinal plants whenever they have health problems. Thus, many people in these developing countries use plants for the treatment of diabetes. Yet, few studies are focused on the knowledge and attitudes of the users on medicinal plants in Africa in general and in Senegal in particular. Hence we undertook this survey on the use of medicinal plants for the treatment of diabetes in Senegal in order to make recommendations which could contribute to the increase of the value of herbal medicines in developing countries. We did a cross-sectional survey by direct interview at a university teaching hospital, in Dakar with a representative sample of 220 patients. Forty-one plants were used by the patients and the two most frequently cited were Moringa oleifera Lam (65.90%) and Sclerocarya birrea (A. Rich) Hochst (43.20%). Patients gave several reasons for using medicinal plants (traditional treatment: 40%, efficacy: 32%, low cost: 20%). The principal suppliers of plants were tradesmen in the market (66.8%) and traditional therapists (5%). Sixty-five per cent of patients think that medicinal plants are efficient for the treatment of diabetes and 20% have reported adverse effects which could be caused by medicinal plants. In conclusion, many people in our study think that medicinal plants are efficient for the treatment of diabetes, which requires research work by scientists in developing countries in this field in order to prove their efficacy and innocuousness.

[Prescription of benzodiazepines by general practitioners in the private sector of Dakar: survey on knowledge and attitudes]. / Prescription des benzodiazépines par les médecins généralistes du privé à Dakar: Enquête sur les connaissances et les attitudes.

OBJECTIVE: The objective of this study was to evaluate knowledge and attitudes of general practitioners of the private sector, in Dakar, concerning prescription of benzodiazepines, in order to make, possibly, recommendations for their rational use. METHOD: A survey was done in 2005 with a representative sample of 55 medical doctors. Medical doctors filled in the questionnaire which focused on the main benzodiazepines' indications, those prescribed and their rules of prescription. RESULTS: The main indications were anxiety, convulsions, epilepsy and insomnia and the benzodiazepines prescribed in first intention were prazepam against anxiety and insomnia and diazepam against convulsions and epilepsy. Practically 17% of medical doctors ignored the existence of limited period of benzodiazepine use and 70.9% of medical doctors considered their training on benzodiazepines insufficient. CONCLUSION: These results show the necessity to base continuous training for these general practitioners on the pharmacology of benzodiazepines.

Benzodiazepines prescription in Dakar: a study about prescribing habits and knowledge in general practitioners, neurologists and psychiatrists.

Benzodiazepines are relatively well-tolerated medicines but can induce serious problems of addiction and that is why their use is regulated. However, in developing countries like Senegal, these products are used without clear indications on their prescription, their dispensation or their use. This work focuses on the prescription of these medicines with a view to make recommendations for their rational use. Benzodiazepine prescription was studied with psychiatrists or neurologists and generalists in 2003. Specialist doctors work in two Dakar university hospitals and generalists in the 11 health centres in Dakar. We did a survey by direct interview with 29 of 35 specialists and 23 of 25 generalists. All doctors were interviewed in their office. The questionnaire focused on benzodiazepine indications, their pharmacological properties, benzodiazepines prescribed in first intention against a given disease and the level of training in benzodiazepines by doctors. Comparisons between specialists and generalists were made by chi-square test. Benzodiazepines were essentially used for anxiety, insomnia and epilepsy. With these diseases, the most benzodiazepines prescribed are prazepam against anxiety and insomnia and diazepam against epilepsy. About 10% of doctors do not know that there is a limitation for the period of benzodiazepine use. The principal reasons of drugs choice are knowledge of the drugs, habit and low side effects of drugs. All generalists (100%) said that their training on benzodiazepines is poor vs. 62.1% of specialists, and doctors suggest seminars, journals adhesions and conferences to complete their training in this field. There are not many differences between specialists and generalists except the fact that specialists prefer prazepam in first intention in the insomnia treatment where generalists choose bromazepam. In addition, our survey showed that specialists' training in benzodiazepines is better than that of generalists. Overall, benzodiazepine prescription poses problems particularly in training, and national authorities must take urgent measures for rational use of these drugs.

Opposite to alpha2-adrenergic agonists, an imidazoline I1 selective compound does not influence reflex bradycardia in rabbits.

This work aimed to study the respective effects of central alpha2-adrenergic receptors (alpha2-ARS) and I1 imidazoline receptors (I1Rs) in the facilitatory effects of imidazoline-like drugs on the reflex bradycardia (RB). Experiments were performed in anaesthetized rabbits. The reflex bradycardic response was induced by phenylephrine injected i.v. LNP 509, rilmenidine and dexmedetomidine were administered intracisternally (i.c.). LNP509 (1 mg/kg, i.c.), a ligand highly selective for I1Rs, induced hypotension (54+/-3 vs. 93+/-2 mm Hg) and bradycardia (260+/-13 vs. 322+/-13 beats/min) (p<0.05, n=5) but did not affect RB. Rilmenidine (1 microg/kg, i.c.), a hybrid ligand which binds to both I1 and alpha2-ARS, also decreased arterial pressure (61+/-2 vs. 101+/-2 mm Hg) and heart rate (260+/-4 vs. 308+/-8) (p<0.01, n=5); it potentiated the RB (maximum R-R interval: 284+/-17 vs. 196+/-6 ms) (p<0.05, n=5). Dexmedetomidine (1 microg/kg, i.c.), a ligand selective for alpha2-ARs, reduced blood pressure (53+/-3 vs. 104+/-2 mm Hg) and heart rate (246+/-4 vs. 312+/-8 beats/min) (p<0.05, n=5) and potentiated the RB (maximum R-R interval: 518+/-38 vs. 194+/-4 ms) (p<0.05, n=5). The potentiation of RB was much greater than that observed with rilmenidine and was significantly prevented by L-NNA injected centrally. This study shows that: (i) an exclusive action on I1Rs which decreases arterial pressure, does not potentiate the RB ii) activation of alpha2-ARs potentiates the RB (iii) the R-R prolongation caused by alpha2-ARs stimulation is prevented by central NOS inhibition.

Myorelaxant and antispasmodic effects of the aqueous extract of Mitragyna inermis barks on Wistar rat ileum.

Mitragyna inermis is used in the Senegal traditional medicine for treating stomach and intestinal disorders. At concentrations of 0.5, 0.75 and 1 mg/ml, the aqueous extract of M. inermis bark (AEMIB) significantly induced a decrease of the ileal basal tonus, respectively, from 37+/-1, 51+/-1 and 75+/-2% (P<0.05; n=5), compared to the baseline values. As well as atropine, AEMIB inhibited submaximal contractions induced by 0.01 mg/ml ACh with IC(50) value of approximately 0.75 mg/ml (n=5). These results show that AEMIB possesses both myorelaxant and antispasmodic actions in the ileum. This may justify the pharmacological basis for the popular use of Mitragyna for the treatment of gastrointestinal disorders.

Nitric oxide discriminates the sites and mechanisms of action of centrally acting anti-hypertensive drugs in rabbits.

The aim of the present study was to further investigate the mechanisms of the central hypotensive action of catecholamines and imidazolines, in particular the role of nitric oxide (NO). Microinjections into the nucleus reticularis lateralis (NRL/RVLM) located in the rostroventrolateral part of the medulla (RVLM) and/or into the nucleus tractus solitarii (NTS) were performed in pentobarbital-anesthetized rabbits. Microinjections of brimonidine (1 ng/kg), which binds both alpha(2)-adrenergic receptors (alpha(2)-ARs) and I(1) imidazoline receptors (I(1)Rs), into the NRL/RVLM induced hypotension (69+/-2 vs. 88+/-2 mm Hg) (p<0.05). Microinjections of S23757 (1 microg/kg), an antagonist highly selective for I(1)Rs, into the same site, prevented the hypotensive effect of brimonidine. These data show that the hypotensive effects of low doses of brimonidine involve the I(1)Rs of the NRL/RVLM. Alpha-methylnoradrenaline (alpha-MNA) (0.5 microg/kg) microinjected into the NTS induced hypotension (76+/-4 vs. 91+/-4 mm Hg) (p<0.05). Microinjections of a low dose of brimonidine (1 ng/kg) into the NTS had no blood pressure (BP) effect at all. In contrast, a higher dose (10 ng/kg) acting on alpha(2)-ARs induced hypotension (72+/-3 vs. 96+/-2 mm Hg) (p<0.05). Nomega-Nitro-L-arginine (L-NNA) (1.5 microg/kg) injected into the NRL/RVLM prevented the hypotensive effect of both alpha-MNA and the higher dose of brimonidine injected into the NTS. Bicuculline (1.5 microg/kg) injected into the NRL/RVLM prevented the hypotensive effect of alpha-MNA injected into the NTS. It is demonstrated that (i) the activation of alpha(2)-ARs of NTS triggers a neuronal GABAergic pathway projecting to the NRL/RVLM region which is NO dependent (ii) both alpha(2)-adrenergic (NTS) and non-adrenergic I(1)R (NRL/RVLM) mechanisms account for the very powerful hypotensive effect of brimonidine, a compound with high affinities at both types of receptors.