Adverse drug reaction (ADR)

Methotrexate is considered as the standard drug treatment for Rheumatoid arthritis. The purpose of this study is to find out the incidence of Adverse Drug Reactions (ADR), and possible risk factors in patients of rheumatoid arthritis administering methotrexate. And to determine the possibility of any new adverse drug reaction that is not well explored in previous studies. An observational follow up study designed and conducted using Naranjo scale to identify the adverse drug reactions in rheumatoid arthritis patients administering methotrexate in KIM’s Hospital.  The objective is to identify the dose dependent adverse drug reactions in rheumatoid arthritis patients and identify possible risk factors associated adverse drug reactions of methotrexate of methotrexate. Toxic effects may occur hours, to days to weeks after methotrexate administration and or overdose, the purpose of this study is to determine the relation between the dose and the occurrence of adverse drug reaction of methotrexate. During the study period clinically relevant adverse drug reaction have been presented by the patients taking methotrexate who attended hospital for their regular checkup. For example, the most commonly reported adverse drug reaction is abnormal taste for food and other less commonly presented adverse drug reaction include diarrhea, constipation, nausea, vomiting, and alopecia. In female patient’s 20-49 age group reported adverse drug reaction like amenorrhea, dysmenorrhea. Methotrexate toxicity develops due to increased patient susceptibility during the treatment.

Drug-drug interaction is a matter of deep concern as this proves to be the major cause of adverse drug reaction (ADR). It may be on pharmacokinetic or pharmacodynamic level. Pharmacokinetic interactions involve the effect of absorption, distribution, metabolism and excretion whereas pharmacodynamic interactions emphasize mainly on three areas viz.,  interactions that occur at single receptor site, at variety of receptor sites and general non-specific interactions mediated through unspecified sites of action. Different factors are responsible such as genetic constitution, disease, diet, pharmacological response and polypharmacy, age related physiological changes on the basis of the outcomes obtained on the clinical effects of the drug used. This article reflects a clear picture on drug-drug interactions for cytochrome p-450 and non steroidal anti-inflammatory drug (NSAIDs), antihistaminic drugs, antidepressants, interactions with antiretrovirals and Rifampin, anti-anaemic agents, dermatological drugs, antipsychotic drugs, major antibiotics, sedative-hypnotic and anti-cancer drugs.