In the present study we found that CDRs, was one of the most common types of ADRs found in the IGGMC and H, which contributes 33.04% of total ADRs. Various studies suggest that the contribution of CDRs is 2-40% in total adverse drug reactions.[7
In the present study the morphological varieties of CDRs commonly reported were maculopapular rash and fixed drug eruptions followed by urticaria, pruritus, tinea incognito (flaring of tinea) and acneiform eruptions. Acneiform eruptions and tinea incognito were found to be mostly due to self medication (89) of topical steroids and repeated use of older prescriptions . Various studies and literatures have already concluded that maculopapular rash is the most common CDRs.[7
The commonest offending drug group for CDRs was antimicrobials (55.5%). The second most common offending drug group being NSAIDs (18.56%) while steroids was third most common group (12.61%).
A study performed by Ghosh, et al
. in Manipal found that antimicrobials (30%) were the most common group causing CDRs.[7
] Another study done by Jhaj, et al
., found that maculopapular rashes (50%) and urticaria (21.5%) were common morphological CDRs and antimicrobials (56.9%) were the most common culprits.[8
] Also Noel, et al
., found that maculopapular rash was (35%) the most common CDR in the hospitalized patients.[9
] Chatterjee, et al
., in their study also found that antimicrobials were topmost in causation of CDRs (34.10%) followed by anticonvulsants (32.88%) and NSAIDs (21.51%).[3
] Results of our study were comparably similar to above mentioned studies.
The common offending drugs causing CDRs are mentioned in the . Cotrimoxazole (20.41%) showed highest CDRs followed by betamethasone 9.06%, ibuprofen (7.91%), ampicilin (6.54%), diclofenac sodium (4.7%), and iron dextran (3.44%). This list corresponds with the results of some studies done in India.[10
] A study performed by Pundukadan, et al
., also found that the most common drug causing CDRs was cotimoxazole (22.2%).[11
In our study most of the offending drugs were taken orally (682) or topically (143) and least by parenteral route (47).
In our study causality analysis was done by using WHO assessment scale and it was found to have 580 certain, 260 probable and 32 possible CDRs. Causality analysis was done completely by consulting the treating physician, dermatologist and thorough literature review. Challenge and Re-challenge was not in any case .
Most of the ADRs were avoidable and treatable and subsided after symptomatic treatment. 17 CDRs were found to be serious, 10 of Steven Johnson Syndrome (SJS) (2 were fatal), 6 of anaphylaxis with angioedema and 1 case of dapsone sensitivity syndrome which required immediate medical attention and hospitalization. In the study of 464 case series reported by Kauppinen K. found that 4% patients had SJS.[12
There might be many causes for the higher incidence of ADRs to a particular drug in this study. Limited list of drugs are supplied for dispensing in Govt. hospitals like others. Patient visiting our hospital OPDs belong to low socioeconomic class and thus can not afford to buy medicines from private pharmacies. So the patients on a treatment seem to develop ADR with the medication available in this hospital. Hence this data may not be truly reflective of the whole population which may be exposed to a large variety of drug formulations. Secondly, due to poverty, patients are likely to prefer older prescriptions for self medicating a particular ailment rather than revising the physician. As such total 95 ADRs due to self medication were found consisting of acneiform eruptions (32-Betamethasone 30 and clobetasol 2) and tinea incognito (57-Betamethasone 46 and clobetasol 11). In our study most patients themselves used steroid ointment to treat acne and tinea cruris causing CDRs.
As this study was based on spontaneous ADR reporting, under reporting, which is the major limitation of spontaneous method of ADR reporting, cannot be denied. Despite the limitations and variations in the study, this data may be important for the clinicians to report the ADRs and avoid irrational drug use. This data also reveals the dangers of self medication of drugs over the counter, which is generally thought to be harmless stuff.
What is new?
CDRs evolved as most common cause of ADR around 33.04%. Topical and oral steroids are the third common cause for CDR followed by antimicrobials and NSAIDs. It is also important to evaluate safety in OTC drugs and in preparations like ointment and creams.