A 65-year old man, on Warfarin treatment, is started on antitubercular treatment. The pharmacologic effect of Warfarin is likely to:
Warfarin Interaction with Antitubercular Treatment
When a patient on Warfarin therapy starts antitubercular treatment (ATT), a significant drug interaction occurs affecting Warfarin's effectiveness.
Mechanism of Interaction
- Enzyme Induction: Key drugs in ATT, particularly Rifampicin, are potent inducers of hepatic cytochrome P450 (CYP) enzymes.
- Warfarin Metabolism: Warfarin is primarily metabolized (broken down) by these CYP enzymes.
- Increased Metabolism: Enzyme induction by ATT speeds up the metabolic process of Warfarin.
Effect on Pharmacologic Activity
The accelerated metabolism leads to lower concentrations of active Warfarin in the bloodstream. Consequently, the drug's ability to inhibit blood clotting (its pharmacologic effect) is reduced.
Therefore, the pharmacologic effect of Warfarin is likely to Decrease when initiated concurrently with antitubercular treatment.
Important Questions from Tuberculosis
- For Acid Fast Bacilli (AFB) to be detected in sputum by the direct microscopy, the bacillary burden in sputum typically is:
- The Gene X-pert test used for MTB detection has the additional advantage of detection of which of the following?
- Recommended first time drug for initial treatment of tuberculosis include all EXCEPT:
The most frequent adverse reaction of significance among people treated for drug-susceptible tuberculosis is:
All adult patients in whom anti-tubercular treatment is being started should undergo baseline assessment of:
