Drug utilization research: a review

Data from drug utilization research is an invaluable resource for all stake holders involved in drug and health policies. Drug utilization is “marketing, distribution, prescription and use of drugs in a society, with special emphasis on the resulting medical, social and economic consequences”. Research on drug utilization includes factors related to prescribing, dispensing, administering and intake of medication and its associated events. The ultimate purpose of drug utilization research is to estimate the optimal quality of drug therapy by identifying, documenting, analysing problems in drug utilization and monitoring the consequences. It encourages the prescribers to prescribe correct drug at appropriate dose and affordable price. It contributes to the knowledge of rational use of drugs in the society; whether the drug is being prescribed appropriately, whether the drug is taken in correct dosage, whether the drug is available at affordable price or misused. It provides valuable feedback about the rationality of the prescription to the doctors. It also assesses whether an intervention affects the drug use in the population by examining the outcomes of different types of intervention given to improve rationality in drug use. Drug utilization research can be qualitative or quantitative and can be done by various methods. This review highlights the understanding of various aspects, different designs and WHO guidelines for conducting drug utilization research.

A rapid and efficient protocol for in vitro multiplication of genetically uniform Stevia rebaudiana (Bertoni).

Stevia rebaudiana (Bertoni), commonly called candy leaf or sweet leaf, endemic to South America, is an important medicinal plant. As a source of low calorie natural sweetener ‘stevoside’, it is used in obesity, diabetes, treatment of heartburn and tooth decay, and also serves as a food supplement. Large scale commercial propagation of S. rebaudiana demands a suitable protocol. Here, we propose an improved protocol for in vitro multiplication of S. rebaudiana from nodal explants. In this protocol, the effect of laboratory grade urea on multiple shoot induction from nodal explants was studied. The nodal explants were initially cultured on Murashige and Skoog (MS) basal media for 2 weeks which facilitated the axillary bud break. Further, culturing of these explants on MS medium fortified with 6 benzyl aminopurine (BAP) (2 mg/L) and Naphthalene acetic acid (NAA) (1 mg/L) with and without urea (5 mg/L) for a period of 40 days revealed maximum shoot production of 44.56 from a single nodal explant in media supplemented with urea as compared to 22.44 without urea. The differences in the number of shoots produced were significant and these shoots readily rooted in MS media with NAA (4 mg/L). Primary and secondary hardening was successful in these plants. There were no visible morphological abnormalities observed in the micropropagated plantlets. Genetic analysis from random samples also revealed that these plants are genetically uniform. The advantage of the present protocol is that the complete process of multiple shoot induction, rooting and hardening could be completed within a period of 6 months as compared to the existing protocols.

Evaluation of analgesic activity of irbesartan in albino mice.

Background: The objective was to evaluate the analgesic activity of irbesartan in albino mice. Methods: Swiss albino mice weighing 25-30 g of either sex were selected for the study. Six animals were allocated to each experimental group. The control group received normal saline (25 ml/kg, p.o.), standard group received pentazocine (10mg/kg, intraperitonial [i.p.]) and test group received irbesartan (20 mg/kg, p.o.). The above drugs were administered 1 hr prior to the experiments. In case of visceral pain model 0.6% acetic acid was given i.p. 30 mins prior to the experiment to induce writhing, in thermal pain model pretreated mice were placed on Eddy’s Hotplate maintained at 55°C and in mechanical stimulus pain model an artery clip was clamped at the base of the tail of pretreated mice. Decrease in total number of writhes in acetic acid induced writhing model and delay in reaction time in both Eddy’s hot plate and Tail clip method denoted analgesic activity respectively. Results: The test drug signifi cantly decreased the total number of writhes in acetic acid induced writhing model in mice. The percentage inhibition of writhing was signifi cant which was 84.35% in the standard group and 59.24% in the test group. The test drug signifi cantly delayed the reaction time in both Eddy’s hot plate and tail clip method when compared to control group and standard group. Percentage increase in latency period when compared to standard drug was signifi cant and measured 73.11% and 64.31% at 60 min in both Eddy’s hot plate and tail clip method, respectively. Conclusion: Irbesartan exhibits analgesic activity in albino mice.

Free radical scavenging activity and reducing power of Gnidia glauca (Fresen.) Gilg.

The present study describes the free radical scavenging activity and reducing power of methanolic leaf extract of Gnidia glauca (Fresen.) Gilg.using ABTS [2, 2' azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)], FRAP (Ferric reducing antioxidant power) and nitric oxide scavenging assays. Total antioxidants were determined by phosphomolybdenum method. The results have indicated that the total phenolic content of the extract was 203.3 GAE/g and showed significant antioxidant activity with an IC50 value of 16.3μg/mL in ABTS and 360.8μg/mL in nitric oxide scavenging assays respectively. A FRAP value of 993.7 μm TE/mg of leaf extract was recorded at 30 minutes. The total antioxidant activity was 142.5 mg AAE/g of extract. The results strongly establish the significant antioxidant property of G. glauca owing to its high phenolic content.

Alpha-adrenergic receptor blocking effect of Cleistanthus collinus (Roxb.) Benth. and Hook f. leaf extract on guinea pig isolated smooth muscle preparations.

Aqueous extract of C. collinus leaves inhibited norepinephrine induced contraction in guinea pig vas deferens and aortic strip in a dose-dependent manner. Inhibition of acetylcholine induced contraction in ileum was dose independent. C. collinus extract per se had no effect on isolated guinea pig vas deferens and aortic strip, but inhibited norepinephrine induced contraction in a dose-dependent manner probably by its antagonist action on α-adrenergic receptor. It had inconsistent effect on guinea pig ileum in vitro preparation.

Comparative evaluation of formocresol and mineral trioxide aggregate as pulpotomy agents in deciduous teeth.

Aim: To evaluate and compare mineral trioxide aggregate (MTA) and formocresol as pulpotomy medicaments by clinical and radiographic assessments and to assess the histological features of both pulpotomy medicaments in deciduous teeth. Materials and Methods: This study was performed on 100 mandibular deciduous molar teeth requiring pulpotomy treatment. Children between age four and six years were randomly selected and divided into formocresol or MTA group. The patients were recalled after 3, 6, 9, 12 months respectively and evaluated clinically and radiographically. Histological assessment was done on lower deciduous canine teeth, which were undergoing serial extraction for interceptive orthodontic purpose. Pulpotomy was done on four teeth with formocresol and another four teeth with MTA. The teeth were extracted after six months following pulpotomy procedure and histologically evaluated. Two freshly extracted carious teeth were taken as controls. Results: Clinical and radiographic criteria were laid and Chi analysis revealed significant difference in mobility ( P≤0.05), periodontal ligament widening ( P≤0.01 level) and inter - radicular radiolucency ( P≤0.02 level) between two groups at the end of 12 months. Histologically, in MTA group, a layer of new dentine formation with less dentinal tubules at the pulpotomized site was found. In formocresol group, increased inflammatory cells, a zone of atrophy, were noted in radicular portion of pulp. Conclusion: MTA is superior to formocresol clinically, radiographically. Histological analysis showed better reparative ability with hard tissue barrier formation with MTA compared to formocresol.

Role of melatonin against oxidative tissue damage induced by Cleistanthus collinus in rat brain.

Background & objectives: The leaves of Cleistanthus collinus, an extremely poisonous plant are consumed for suicidal purposes in various parts of India. The mortality rate is high and there is no antidote. In this study, we attempted to delineate oxidative stress as a possible mechanism of action of C. collinus toxicity in rats and the role of melatonin against injury to brain and heart caused by C. collinus. Methods: Adult Wistar rats (130 -200 g, n = 6 per group) of either sex were used. C. collinus at 8 mg/kg body weight (LD50) was administered orally followed by melatonin 15 mg/kg body weight ip or cysteine 500 mg/kg body weight ip (standard) after 2 h. Malondialdehyde (MDA), reduced glutathione (GSH), glutathione peroxidase and catalase levels in brain, heart and blood were estimated and histopathological examinations (brain and heart) were done. For the survival study, rats were treated with increasing doses of melatonin (5, 10 and 15 mg/kg body weight ip) following a lethal dose of C. collinus (10.5 g/kg body weight orally). Results: The results showed a significant (P<0.05) increase in blood and brain MDA levels and decrease in tissue GSH in the LD50 group. This was accompanied by marked gliosis, spongiform necrosis and lymphocytic inflammatory infiltrates in brain and marked congestion, inflammation and muscle necrosis in heart. Melatonin significantly (P<0.05) reduced lipid peroxidation and reversed the histopathological changes induced by C. collinus in the brain but not in the heart. Interpretation & conclusion: Our results suggest that oxidative mechanisms play an important role in C. collinus induced tissue damage and melatonin, by balancing oxidant-antioxidant status ameliorates oxidative organ injury in brain due to C. collinus toxicity.

Newer insulin analogues and inhaled insulin.

Diabetes is a metabolic disease with high prevalence worldwide. Exogenous insulin is used in the management of this condition. The development of human insulin has provided tighter control of glycaemia in diabetic patients. Insulin analogues like insulin lispro and aspart were developed to closely match its profile with physiological secretion. The newer additions to this armamentarium are insulin glulisine, insulin detemir and albulin.Insulin glulisine is a short acting analogue with a rapid onset of action. The antiapoptotic property, mediated through insulin substrate receptor-2 has a favourable protective action on beta cells. Insulin detemir is a long acting analogue, soluble at neutral pH, which reversibly binds to albumin in plasma, prolonging its action. Its lower affinity for insulin receptors necessitates higher doses compared to human insulin. The reduction in body weight is an additional advantage of detemir. A major concern about all newer insulin analogues is their altered mitogenic properties and resultant risk of carcinogenicity on long term use. Albulin is a latest addition of insulin analogue which is under various in vitro and in vivo studies. Inhaled insulin in powder form (Exubera) is recently approved by FDA and appears promising.

Oral health status of 5 years and 12 years school going children in Chennai city - An epidemiological study.

India, a developing country, faces many challenges in rendering oral health needs. The majority of Indian population resides in rural areas of which more than 40% constitute children. The purpose of this study was to assess the oral health status of 5 years and 12 years school going children in Chennai city. The study population consisted of 1200 school children of both the sexes (600 private and 600 corporation school children) in 30 schools, which had been selected randomly. The survey is based on WHO, 1999 Oral Health Assessment, which has been modified by including gingival assessment, enamel opacities/ hypoplasia for 5 years. Evaluation of the oral health status of these children revealed, dental caries is the most prevalent disease affecting permanent teeth, more than primary teeth and more in corporation than in private schools, thereby, correlating with the socioeconomic status. It may be concluded that the greatest need of dental health education is at an early age including proper instruction of oral hygiene practices and school based preventive programs, which would help in improving preventive dental behaviour and attitude which is beneficial for life time.

Comparative evaluation of glass ionomer and resin based fissure sealant using noninvasive and invasive techniques--a SEM and microleakage study.

The efficacy of using invasive and non-invasive techniques was assessed by Scanning electron microscopy, and by microleakage of Glass ionomer (GC VII, Fuji) and Resin based sealant (Helioseal-F, Ivoclar Vivadent). 100 young premolars were used for this study, and they were divided into four groups: Group I: non-invasive technique GC VII, Group II: Invasive GC VII, Group III: Non-Invasive Helioseal-F, Group IV: Invasive, Helioseal-F. 5 teeth from each group were evaluated under SEM. It was seen that the flow and adaptation of GC VII was slightly better than Helioseal F, and the invasive technique provided the best flow and adaptation. For microleakage analysis 5% methylene blue was used. It was seen that minimal microleakage was seen in Group IV (P<0.01). Considering the recent controversies using resin based sealants, it can be said that GC VII can be a viable alternative for pit and fissure sealants.