TB pills most effective before eating —Study

In a study that could change the intake schedule of tuberculosis drugs, a group of researchers have found that food reduces the effectiveness of most medicines prescribed as the first line of treatment for the infection.

In the study, the researchers at the National Institute for Research in Tuberculosis (NIRT) found significantly lower concentrations of anti-TB drugs and a delay in their absorption when the pills are consumed with food.

The research, which was published in Indian Journal of Medical Research, involved studying 25 TB patients in Chennai who took their medications after breakfast.

The same group was examined after a 12-hour over night fast, followed by drug administration and breakfast two hours later. The three key first-line drugs they studied are rifampicin, isoniazid and pyrazinamide.

Dr Soumya Swaminathan, director general of Indian Council of Medical Research and one of the co-authors of the study, said though most doctors are aware of the clinical impact of food on rifampicin, guidelines on when to take the other drugs are hazy.

She said that findings of the study indicated that at least two other first-line drugs need to be taken on fasting aside rifampicin, adding that the findings are significant as the dosage of first-line drugs is low.

They found drug administration with food caused the time taken for drug to start taking effect after absorption in blood to decrease by 50 per cent, 45 per cent and 34 per cent for rifampicin, isoniazid and pyrazinamide, respectively.

It is a common believe that drugs are not well tolerated on an empty stomach and many patients prefer to have food before they take medicines.

But, Dr Olanisun Adewole, a chest physician at the Obafemi Awolowo University Teaching Hospitals Complex (OAUTH), Ile Ife Osun State, stated that in Nigeria, it is a common practice to ask TB patients to take their medications at least one hour before their meals to ensure their effectiveness.

He stated, “That is essentially what we teach, that is what our patients have been doing. They take their medicines on an empty stomach.

“But by the time, the patients take the drug like that for three days, they get used to taking it on an empty stomach. Initially, they may have some nausea and vomiting because they have not taken any food, but with time they get stabilised.”