Advancement in antimicrobials (AMs) has resulted in good success rates for life-threatening infections. However, the selection of AM is largely inter- and intrapersonal. The lack of standardization in selection of AMs leads to widespread misuse, AM resistance add up the cost for the patients and healthcare. Judicious and restricted use of newer broad-spectrum AMs can help tide over the emerging worldwide crisis of AM resistance. Hence, the present study was conducted to evaluate the pattern of use of AMs in hospital inpatients and change over ten-year time period.
Inpatient charts of 1 000 patients of both genders admitted between 1995 and 2005 at the Post Graduate Institute of Medical Education and Research, Chandigarh, India, were analyzed. These charts were stored in central records department as per serial inpatient number. After taking due permission from the medical superintendent of the hospital, the inpatient charts pertaining to all the medical and surgical specialities were screened manually. The AM use was noted only once for a given patient, irrespective of the dose, duration, route, response to therapy, or any other concomitant therapy. The patients using any of the AMs were noted. To determine the percentage of patients on AMs with a precision of 99% and variability of 5%, sample size required was 661. 1 000 charts of 1995 and 2005 each were included. Usage of individual AMs was compared between 1995 and 2005 using chi-square statistics with Yates correction or by Fisher's exact test. Individual AMs that had usage of more than 2.5% in any of the years alone were compared.
Our study showed a significant increase in the prescription of AMs in 2005 as compared with 1995 (570 vs 482, P<0.001) as also the total number of AMs prescribed (1 118 vs 793) [Table 1]. There was increase in the use of amoxicillin-clavulanic acid, metronidazole (P<0.001), amikacin (P<0.001), and third- and fourth-generation cephalosporins, especially cefotaxime, ceftriaxone, and cefepime. This may be due to the improved and extended antimicrobial spectrum of these AMs. However, crystalline penicillin, cotrimoxazole, and chloramphenicol use showed a significant fall (P<0.001).
Penicillin and cephalosporin being broad-spectrum, safe, efficacious, and relatively less toxic remained on the top of the list. The antimicrobial spectrum of amoxicillin-clavulanic acid combination has extended activity against certain β-lactamase-producing organisms like staphylococcus, Haemophilus influenzae, gonococci, and Escherichia coli. The combination is routinely indicated for empirical therapy of serious infections in both immunocompromised and immunocompetent individuals and has found place in WHO Essential Medicine List (EML).
Newer quinolones have improved efficacy against Gram-positive organisms, an advantage over their predecessors having only Gram-negative spectrum. The newest ones like gatifloxacin having additional activity against anaerobes as well. They are indicated for variety of infections caused by most of pathogenic bacteria like empirical treatment for unknown severe infections, soft tissue infections, bone and joint infections, intra-abdominal and respiratory infections. They are also effective in urinary tract infections, atypical mycobacteria, legionella, etc.
Second-generation cephalosporins like cefuroxime have an extended spectrum of activity against Gram-negative organisms and lesser against Gram-positive ones as compared with first-generation cephalosporins. It can also cross blood-brain barrier with concentration in cerebrospinal fluid (CSF) 10% than that of plasma. It is effective in treating meningitis due to H. influenzae, Neisseria meningitidis, and Streptococcus pneumoniae. Third-generation cephalosporins like ceftriaxone and cefotaxime have expanded Gram-negative coverage and many have the ability to cross blood-brain barrier. They are good as empirical treatment for sepsis of unknown origin or in febrile, neutropenic, immunocompromised patients where a combination with an aminoglycoside helps.
Amikacin is the broadest spectrum aminoglycoside and is also resistant to many enzymes that inactivate gentamicin. This may be partially responsible for physician preferences above gentamicin. Metronidazole is preferred because of its efficacy against anaerobic bacteria, bacteroides, and clostridium species, as well as over and above traditional use against amoebiasis. Penetration into the CSF is very good and is indicated for treatment of brain abscess, mixed aerobic anaerobic infections, H. pylori infection, antibiotic-associated colitis, and also for surgical prophylaxis.
Chloramphenicol use decreased significantly. This may be due to the adverse effects like bone marrow suppression and gray baby syndrome. Sulfonamide allergy and growing evidence of resistance against cotrimoxazole have resulted in significant decrease in its use in hospital setting even when cotrimoxazole is present in WHO EML 2003. However, this drug is now finding place in treating comorbid infections in HIV-seropositive individuals. Hence, the present study observed a definite change in prescribing trend and increase in the number of AM prescriptions in the hospital inpatients. This increase has to be judiciously weighed against the appropriate and rational prescribing.