Overuse of antibiotics harming India's fight against TB: lancet

India, facing the highest burden of tuberculosis (TB) in the world, is also the world's largest consumer of antibiotics, says a study, conducted to determine whether pharmacies have contributed to inappropriate use of antibiotics by dispensing them without prescriptions.

The study, by Indian origin researchers, published in The lancet Infectious Diseases, showed the critical importance of engaging pharmacists for reducing misuse of antibiotics, and for fighting TB.

TB is a potentially serious infectious bacterial disease that mainly affects the lungs.

Excess usage of antibiotics has led to significant antimicrobial resistance that threatens the effective prevention and treatment of TB, as resistant microorganisms (including bacteria, fungi, viruses and parasites) are able to withstand attack by the antimicrobial drugs. 

The findings showed that pharmacies frequently dispensed antibiotics to simulated patients who presented with typical TB symptoms.

However, none of the pharmacies dispensed first-line anti-tuberculosis drugs without prescriptions. 

Antibiotics and steroids (which can be harmful to individuals who actually have TB), were dispensed only when the patient presented with a lab test confirming TB, thus making the diagnosis apparent to the pharmacist, the study said.

"Our study clearly showed that not a single pharmacy gave away first line anti-TB drugs (isoniazid, rifampicin, ethambutol, pyrazinamide and streptomycin) without prescriptions," said Madhukar Pai, Canada Research Chair at McGill University, in Quebec, Canada.

"However, pharmacists gave away other antibiotics and rarely referred patients with typical TB symptoms, and that means they are contributing to delays in TB diagnosis," Pai added.

This can increase transmission of the infection in the community. So, there is great potential to harness pharmacists to identify those who need TB testing in India, the researchers said.

For the study, the team used two standardised patient cases, one with a patient presenting with two to three weeks of pulmonary TB symptoms and a second with a patient with microbiologically confirmed pulmonary TB. 

These trained patients then visited 622 pharmacies in three Indian cities (Delhi, Mumbai, and Patna), completing 1200 interactions with pharmacists. 

After each interaction, the patients remembered what was said to them, and collected all the pills that were dispensed to them by the pharmacists. 

Only 13 per cent of simulated patients with TB symptoms were correctly managed, in sharp contrast to the 62 per cent of patients presenting with known TB who were correctly managed, the data showed. 

"Only a minority of urban Indian pharmacies correctly managed patients with presumed tuberculosis. But most correctly managed a case of confirmed tuberculosis," explained lead author Srinath Satyanarayana, doctoral student at McGill University.