Profile of pharmacological effects of combination of buspirone with selected antidepressants: a behavioral study in mice.

Background: Antidepressants are commonly prescribed drugs. Co-existing disorders like anxiety require therapy with other drugs. The profiles of pharmacological effects of these drugs on central nervous system are influenced by the administration of these drugs either as single or combination. This study is designed to observe the behavioral effects of antidepressants along with the antianxiety agent buspirone in mice. Methods: Four antidepressant drugs belonging to different groups are selected for the study. Amitriptyline, citalopram, venlafaxine and mirtazapine are given orally for 2 weeks. Subsequently, buspirone is added to each antidepressant drug for a period of 3 weeks. The behavioral effects in mice are observed at weekly intervals using photoactometer, rotarod, forced swim test and elevated plus maze. Results: The antidepressant drugs amitriptyline and citalopram showed any change in spontaneous motor activity recorded by photoactometer. In rotarod test venlafaxine showed an increase in values, which showed further increase when buspirone was added. In the forced swim test also, venlafaxine showed a different pattern of effects when compared to other antidepressants. In the elevated plus maze test, the four antidepressants did not show any increase in the time spent in open arm excepting citalopram. Venlafaxine showed an increase in time spent in closed arm. Conclusions: The test drugs do not show any significant depression of central nervous system at the dose used. Venlafaxine showed a different pattern of activity in the rotarod test and swim test. The variation in response is attributed to their effects on central neurotransmitter.

Introduction to concept of personal drugs, essential drug list and awareness of cost of drugs.

Background: Undergraduate medical students acquire knowledge about use of drugs during teaching sessions related to prescription of drugs. Appropriate selection of drugs from the available list of numerous formulations requires skill. This can be imparted using the concept of personal drugs (P-drugs). Knowledge of the price of drugs is important consideration in selection of drug. This paper describes method of introducing medical student to the concept of P-drugs, essential drug list (ED list) and economic aspects of drug utilization. Methods: Students are divided into groups, guided by faculty member. Each group is allotted a clinical case scenario with specific questions; students have to select suitable drugs which can be prescribed. They also have to search for the suitable drug included in the ED list and price of different brands of the same drug. The work done by the group is presented as a report to the whole class. Results: Each group presented the list of P-drugs and ED list and price of the drugs for the selected cases viz.: pharyngitis, urinary tract infection, hypertension, diabetes mellitus. After collecting the information on these aspects each group selected the most appropriate drug for the clinical condition allotted to them. Comparison of prices of various brands provided opportunity to learn about economic aspects of drug use. Conclusion: This method of study using patient oriented problems is a useful method to impart knowledge to medical students about concept of P-drugs, ED list and economic aspects of using drugs.

Effect of potassium channel modulators on toxicity of Cleistanthus collinus.

The study was conducted to determine the effects of boiled extract of Cleistanthus collinus on rats by observing ECG changes and electrolyte levels in serum and urine. Influence of minoxidil and glibenclamide on Cleistanthus collinus induced toxicity was determined. ED50 for arrhythmia, changes in contractility and heart rate were recorded using the isolated frog heart. Cleistanthus at low doses caused transient tachycardia and increase in contractility and at high dose caused arrhythmia and cardiac arrest in rat. LD50 was found to be 1690 mg/kg. Minoxidil potentiated cardiac toxicity, whereas glibenclamide did not produce any significant change. High concentration of potassium in Cleistanthus extract hindered comparison of its levels. There was excretion of sodium even in the presence of hyponatraemia. Cleistanthus at low dose caused transient tachycardia and increase in contractility and at high dose caused arrhythmia and cardiac arrest in isolated frog heart. ED50 for arrhythmia was found to be 1406 mg/kg. Acute toxicity was mainly due to depressive cardiac activity of Cleistanthus. It also caused renal failure. Potassium channel modulators did not have important role in acute cardiac toxicity treatment. Probably in chronic toxicity, electrolyte level changes are involved and potassium channel modulators might have a role.

Analgesic activity of Piper longum Linn. root.

Piper longum root, commonly called Kandantippili, is traditionally used to treat rheumatism, insomnia, palsy and epilepsy. But a scientific study on its central actions is not available. This study screens P. longum root for opioid type analgesia using rat tail-flick method and for NSAID type analgesia using acetic-acid writhing method. Pentazocine (ip) and ibuprofen (oral) are used as respective drug controls. An aqueous suspension of P. longum root powder is given orally to mice and rat in doses of 200, 400 and 800 mg/kg. The delay in reaction time for thermal stimulus in rats and the number of writhings to chemical stimulus in mice are determined in each group. The results are analysed statistically. The 400 and 800 mg/kg doses of P. longum show significant NSAID type of analgesia (P < 0.001). Both Ibuprofen (40 mg/kg) and P. longum (800 mg/kg) show 50% protection against writhing. The delay in reaction time to thermal stimulus was less than 6% for different doses of P. longum as against 100% for pentazocine. This indicates that P. longum root has weak opioid but potent NSAID type of analgesic activity.