US scientists develop database for adverse drug reactions
WHETHER it’s the common paracetamol or clioquinol used sometimes to treat skin infections, side-effects of medicines have always been a matter of concern. It is true that pharmaceuticals list the side-effects of a drug on the package, but it is not enough to know all the adverse reactions that a drug may cause.
For example, in the case of combination drugs one of the compounds may either increase the reaction of another or reduce it. In some cases it may even lead to a new side-effect. For instance, codeine, an analgesic when used in combination with paracetamol increases the analgesic activity of paracetamol. This change in properties, in some cases can be detrimental to health. According to WHO, “Unintended, harmful reactions to medicines are among the leading causes of death in many countries.” Now scientists from Stanford University in the US have designed a database to calculate the adverse effects of drugs. They obtained the data pertaining to adverse drug events maintained by various regulatory agencies such as the Food and Drug Administration. The database is based on drug effects, drug-drug interaction side effects and drug targets.
“We think we have generated a good list of potential drug interaction and drug side-effects,” says Russ B Altman, one of the scientists. The study was published in the March issue of Science Translational Medicine.
Though the database concept for drug effects is not new, those developed earlier lack crucial information such as co-prescribed medications and patient demographics. For this reason analysis of drug effects is compromised. But the scientists from the university say their database is free from the limiting factors. “We have analysed all aspects of a drug so it is more sensitive to picking up side-effects,” says Altman. For example through the database we found that a combination of thiazides diuretics (used to treat hypertension) and serotonin reuptake inhibitors (antidepressants) can cause abnormal heart rhythms. This can lead to palpitations and even death, he adds.
Before a drug is given a clean chit, it goes through clinical trials. But these trials are conducted on a small population and the effect of only one drug is taken into consideration. So the only way to know side- effects is through post marketing surveillance. In it, the regulatory agencies, pharmaceuticals and healthcare professionals keep a tab on the adverse effects.
Developed countries have a comprehensive database of such reports. However, in India the pharmacovigilance programme is still in its nascent stage. “We have started collecting data from last year only on adverse drug effects,” says C Adithan, head of the Regional Pharmacovigilance Centre, South. “The study can help remove some of the confounding factors in studying drug side-effects,” he adds.