Wednesday,
July 22, 1998
|
|
| Why
drugs are a double-edged sword ALL drugs are to be handled with care. There is none which does not have toxic effects. It is the right use of a drug, in the right dose, at the right time, to the right people and price which differentiates a remedy from a poison Thank your mother for intelligence DO we inherit our father’s emotions and our mother’s brains? On first thoughts, such an idea might seem ridiculous. However, pioneering research in mice reveals that the mother’s genes play a major part in development of the parts of the offsprings’ brains that are responsible for their intelligence. Kala-azar may lead to AIDS, hepatitis Kala-azar, the poor man’s disease affecting people particularly in the states like Bihar and West Bengal, may open doors to other deadly blood-borne diseases like hepatitis and HIV infection, warns a study. Medical notes |
| Why drugs are a double-edged
sword By C. S. Gautam and V. K. Bhan ALL drugs are to be handled with care. There is none which does not have toxic effects. It is the right use of a drug, in the right dose, at the right time, to the right people and price which differentiates a remedy from a poison. Every drug has risks and “no chemical can be devised which if given to a woman or man and whether used by oral, nasal, retinal, cutaneous, subcutaneous, rectal or vaginal route will be free of all risks.” |It is tempting to focus only on those drugs that carry obvious risks. However, by doing so we create a misconception that these few substances are the only problem and if they are dealt, with we will be left with a selection of high quality medicines which are effective and affordable. Unfortunately, in practice this is not the case. The pharmacological action of drugs when extended normally and also the way they are prescribed and used leads to side effects. In the wrong hands or at the wrong time, even the most carefully prescribed medicine can become a life threatener instead of being a life saver and the consequences may encompass globally, e.g. the misuse, overuse or abuse of newer antibiotics which have flooded the Asian market. Overenthusiastic use of newer compounds is not only risk prone but also yields many new side-effects in post-market surveillance. Newer macrolides, like roxithromycin, azithromycin or clarithromycin, which incidentally belong to erythromycin class cannot be prescribed with non-sedative antihistaminic compounds, viz. astimazole, because of the likelihood of fatal cardiac arrythmias. However, aestimazole may not lead to this fatal side-effect with erythromycin. Another problem is the developing resistance to antimicrobials and the inclusion of antibiotics in many antidiarrhoeal preparations, despite the knowledge that around 50 types of viruses are the cause of diarrhoea. Such preparations wouldnot lead to desirable beneficial effects. On the contrary, cumbersome adverse effects might be encountered. Another problem is that the way the drugs are tested does not allow some safety information to be collected before their approval and marketing. This may be on account of enrolling of patients in pre-market, clinical trials have relatively uncomplicated diseased conditions and are drawn from the reserved age groups. Most of the times pregnant women or those likely to be pregnant, addicts, children and elderly are excluded from the pre-market clinical trials. However, once the drug floods the market, the same reserve group may be exposed to these drugs with obvious reports of newer side-effects. It is astonishing that 52-55 per cent of the world population is of women, 32 per cent are children under 15 years and 6 per cent people are over the age of 65 years. The two-thirds of the world population is included in the reserve category where more care needs to be taken in the use of drugs and less is known about the side effects of drug. These are also the group of people who are most likely to use drugs, either through self medication or through prescriptions. A Canadian study found that adverse drug reactions are more likley to occur in women and elderly, may be on account of overuse of drugs by this group of people. Nearly 5-20 per cent of hospital admissions are due to adverse drug reactions. Many times the drug industry is responsible for the adverse drug reactions, due to their faulty drug promotional attitude. Unfortunately the prescription drugs are marketed as if they were cosmetics or candy. Claims are made beyond what the product will do. Demand is inflated beyond medical needs. Uses are promoted that are neither healthy nor wise, remarked David Jones, a former executive at both Ciba-Geigy and Abott. The worst problems faced due to these are: many dangerous products are freely available in India which have long back been banned in developed countries. Chemists may not sell them but these are readily available with the grocery shops. Antidiarrheoals, still containing clioquinol or hydroxyquinolines (e.g.Mexaform) responsible for severe nerve damage, are freely available as also analgin which is responsible for fatal blood disorders in patients consuming it for anti-inflammatory, analgesic and antipyretic actions. Contrary to the claims of the pharmaceutical company, many drugs are available which have ineffective, products e.g. various vasodialators and other chemicals promoted as “brain tonics” to improve memory and concentration without documented research. Similarly, kaolin and pectin mixtures are available as anti-diarrhoeal agents and are no more effective than a controlled diet. Irrational drug combinations have flooded the market. Cough and cold preparations which contain an ingredient to encourage cough and another ingredient to supress cough are freely available. Approximately 70-80 per cent cough and cold remedies seen in the market are irrational, mostly ineffective and potentially dangerous. Similarly vitamin E capsules of strength 200mg and 400mg are available which is irrational since as low as 25mg is sufficient to produce beneficial effects. Vitamin E is highly lipid soluble and stays in the body for a long time leading to bleeding disorders at high doses. Two pain killers should not be combined, being taught in pharmacology, is never observed by the industry. There are many painkiller preparations having more than one pain killer responsible for the increased side-effects. Diarrhoea is mostly virus based, but several anti-diarrhoeal preparations are available where antibiotic is added, without any beneficial effect. It ultimately effects the pocket of the patient and compliance. Flooding of market with newer and newer antibiotics would deleteriously effect the pharmaco economics and their overenthusiastic use would yield many new side-effects and bacterial resistance might also develop. We must always depend upon the old, well tried drugs about which sufficient information is available, except in the most compelling situations, e.g. Septran is even used in developed countries like the USA till-date. However it is a drug of past in India. There is anti-obesity drug fenfluramine which is freely available for obesity. The drug is abused or overused by figure conscious females. Recently this drug has been banned in USA because of the valvular defect in the heart. Careful lifestyle modifications can bring about a dramatic relief, while in practice a patient on these drugs feels that he or she has the license to eat any damn thing leading to uncalled for side-effects and failure of therapy. Similarly, appetite stimulant cyproheptadine is an antihistaminic compound for which weight gain is the side-effect. The FDA raised the question about the effectiveness of this compound long time back, but it is freely available in India. Similarly the so-called brain tonics and height raisers are also producing placebo effects only, or more so the side-effects. Self-medication is on the rise and is responsible for several undesirable adverse effects of drugs, about which the patient himself/herself is ignorant-so this practice has to be curtailed. But who drives the patient for self-medication? The media, especially television, where cold and cough remedies are treated with a magic bullet and so also paracetamol is shown to be free from side-effects, sends wrong signals to the layman’s mind and ultimately a clustering of side-effects is seen. Therefore, this type of propaganda has to be stopped. Finally, the consumer product information leaflets are to be asked for any drug which you purchase. One must know what are the possible side-effects and what would happen if therapy is discontinued? Drugs are a wonderful scientific outcome of planned research, but careful selection, dosages, timings, pharmaco economics, life style modifications and compliance would demarcate the beneficial effects versus side-effects and would save the precious life of a patient and also the experts from the claws of the Consumer Protection Act (CPA)  . |
| Thank your mother for
intelligence DO we inherit our father’s emotions and our mother’s brains?, reports UNI. On first thoughts, such an idea might seem ridiculous. However, pioneering research in mice reveals that the mother’s genes play a major part in development of the parts of the offsprings’ brains that are responsible for their intelligence. The father’s genes, on the other hand, may shape not his offspring’s looks so much as those parts of their brains that influence emotional makeups.The findings, published in a recent issue of “New Scientist”, a British science journal, have far reaching implications for the humans. Women seeking intelligent children might decide that choosing easy going husbands is far more preferable to accepting intellectual high fliers as their lifemates. Similarly, men interested in the IQ of their offsprings might suddenly find smart wives more appealing. According to scientists in Britain, the strange genes that threaten even greater social ferment than cloning are called “imprinted genes”. An imprinted gene behaves differently from the normal genes. While the two similar looking `normal genes’ present in the offspring — one from the mother and other from the father — are equally active, the imprinted genes carry a biochemical label that reveals their parental origin and determines whether or not they are active inside the cells of the offspring. Studies by the University of Cambridge researchers Eric Barry Keverne and Azim Sirani on the mouse have revealed that some imprinted genes work in the offsprings only when they come from the mother and are silenced when they are inherited from the sperm. Other imprinted genes work the other way round and are only switched on if they are inherited from the father, they found. The mechanism, which leads to the silencing of these genes in the offspring, depending on their origin, is called “methylation”. In this process, the DNA in a gene is silenced when it is shrouded with small molecular clusters called methyl groups added by enzymes present in either the egg or the sperm. Dr Keverne and Dr Surani have found that in the mouse, the mother’s genes contribute more to the development of the “thinking” or the “executive” centres of the brain, while paternal genes have a great impact on the development of the “emotional” limbic brain. According to them, in addition to the hundreds and thousands of non-imprinted genes that are needed to build a normal human brain, an embryo needs a carefully concocted balance in the activity of genes it receives from its mother and father. In normal mouse — or human — that balance is most likely achieved by imprinting, i.e. silencing, certain genes when they are implanted from one parent. Discussing the implications of the findings, Dr Keverne and Dr Surani say, “It is clear that a human mother’s genes make the biggest contribution to the part of the brain that society values most — the cortex”. In human beings, the cortex is responsible for highly sophisticated intellectual, skills such as language and the ability to plan ahead. It is also exceptionally large in humans and their close primate relatives. On the other hand, the father’s genes contribute more to the extremely ancient “primitive” brain parts. These areas regulate more instinctual behaviours such as feeding, fighting and reproduction, and in primates, including humans, they have withered relative to the size of the cortex over evolutionary time”, the scientist said. During the study, circumstantial evidence has emerged that imprinted genes, indeed effect the development of the human brain in a way not dissimilar to the mouse”, they added. |
| Kala-azar may lead to AIDS,
hepatitis Kala-azar, the poor man’s disease affecting people particularly in the states like Bihar and West Bengal, may open doors to other deadly blood-borne diseases like hepatitis and HIV infection, warns a study, reports PTI. Caused by a sandfly Leishmania donovani, kala-azar is widely prevalent among the people from low socio-economic groups due to poor hygiene and poverty, with Bihar alone bearing half the world’s kala-azar cases. “Since all anti-medications require multiple injections of anti-leishmania drugs we wanted to find out the risk of contracting blood-borne diseases in recipents,” according to team leader Sarman Singh from the Department of Laboratory Medicine at the All-India Institute of Medical Sciences (AIIMS) . Scientists at the AIIMS and the National Institute of Communicable Diseases in Pana surveyed five villages in the leishmania-endemic districts of Bihar covering 4050 families. The study found about 1.5 per cent of population affected by kala-azar and reported “very high” incidence of hepatitis-C and hepatitis-B among those receiving injections. Hepatitis-C was found to be more prevalent with about 20 per cent such patients testing positive while about 13 per cent of them showed hepatitis-B infection. One person was found to be infected with human immuno deficiency virus (HIV) which causes aids, according to the study. “Compared to about 4 per cent of blood donors suffering from hepatitis-B the figure is very high for general population,” Mr Singh says, adding figures are not yet available for hepatitis-C infection among the general population. The study found females at a greater risk of acquiring infections than males. The study also found doctors prescribing injections indiscriminately between five and 120, with some having been on regular dose of injections for the past six years. The glaring disparity among patients prescribed for injections is an indication that under qualified and unscrupulous doctors are randomly prescribing drugs resulting in the disease being “widely over estimated,” Mr Singh said. Normally, a course of 30 injections is enough to cure kala-azar, unless there is a relapse of infection. What is adding to the woes is that injections are routinely administered by healthcare workers who do not observe the basic sterlisation practices, he said. He warned that unless concerted efforts were made to upgrade their knowledge about disinfecting syringes and needles, the negligence may further worsen the already fragile health system in the country. |
| Girls face more risks than boys Adolescent girls in South Asia face greater health-related problems than boys, according to a United Nations Population Fund (UNFPA) report that says national policies had failed to address the need and concerns of adolescents, according to a PTI report. Early pregnancy, high maternal mortality, sexually transmitted diseases (STDs) and poor health are some of the problems that are rising among adolescent girls in developing countries.To address these problems, New Delhi is hosting a three-day South Asia conference on adolescents which began on July 21.The report says STDs tend to be higher among women aged between 15 and 19, than men, partly because they are difficult to reach with STD control and treatment measures.Adolescent girls are also at greater risk of serious complications than men as treatment is often delayed. The delay arises as many are shy to seek medical treatment and symptoms are less obvious in women than men.The UNFPA report says maternal mortality is unacceptably high in South Asia due to early marriage and pregnancy, barring Sri Lanka. One-thirds of South Asian women are married before they reach the age of 20.Pregnant adolescent girls in the age group of 15-19 years carry a 20-200 per cent greater risk of dying during pregnancy or delivery than older women, it says.Early marriage coupled with familial pressures for early motherhood adversely affects their health resulting in inadequate growth, undernutrition, high blood pressure and anemia.The report notes that with urbanisation and poverty on the rise, young girls are “often the prime targets for trafficking” making them more susceptible to STDs and AIDS Stopping smoking affects pleasure? SCIENTISTS at the California-based Scripps Research Institute have claimed that persons stopping smoking many lose their ability to experience pleasure, according to ANI.Dr Alan Leshner, Director of the US National Institute on Drug Abuse, said nicotine addiction caused dramatic changes in the human brain’s pleasure circuits, and withdrawal could decrease the brain’s sensitivity to pleasurable stimulation.He said understanding this phenomenon could help in development of better treatments for withdrawal symptoms like depression, anxiety, irritability and craving — that interfere with people’s attempts to quit smoking. ”The study was conducted by Dr Athina Markou and her colleagues. They used rats to measure brain sensitivity to pleasurable electrical stimulation. Their research was published in the scientific journal Nature.The scientists measured pleasurable electrical pulses associated with the hypothalamus area of the brain.The rats administered the pulses to themselves both before and after being given nicotine. During a week when the rats had the nicotine equivalent of smoking one and a half packs of cigarettes a day there was no change in the electrical pulses they gave themselves. But when the nicotine was withdrawn, the intensities of the electrical circuits had to be increased by more than 40 per cent before the rats found them enjoyable. According to medical experts, smoking is a major preventable cause of death throughout the world. More than half a million Europeans die from smoking related diseases every year.Many smokers who do not die from the habit develop debilitating diseases such as chronic bronchitis, emphysema and cardiovascular disease. Viagra sales likely to hit $1 billion SALES of Pfizer Inc’s blockbuster impotence drug, Viagra, will likely hit $1 billion in its debut year on the market although only a minority of users are being reimbursed by insurers, according to market research firm IMS Health, reports Reuters.The blue diamond-shaped pills became a sensation when Pfizer began shipping them to US drugstores in early April, capturing top media play.The IMS, which keeps tabs on pharmaceutical sales trends, said Viagra was the “most successful product launch” of any prescription drug. |
| . |  |