Moderate
Digoxin × Rifampicin
Cardiac glycosides (digitalis)×Antituberculous antibiotic
Mechanism
Rifampicin induces enterocyte P-glycoprotein. Digoxin bioavailability falls by 30%, levels drop — risking loss of rate control in atrial fibrillation or worsening of chronic heart failure.
Symptoms
Return of underlying disease: tachycardia in atrial fibrillation, dyspnoea and oedema in chronic heart failure. After rifampicin stops, digoxin levels may rise sharply.
Management
On the combination, check digoxin levels at 2 and 4 weeks after rifampicin start and 2 weeks after rifampicin stops. Digoxin dose is usually raised by 25–50% during rifampicin and returned to baseline afterward. In atrial fibrillation, consider adding a beta-blocker (bisoprolol, metoprolol) for rate control.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.