Acetylsalicylic acid × Calcium carbonate

Antacids accelerate renal aspirin elimination via urinary alkalinisation. At cardioprotective doses (75–100 mg/day), the effect is clinically minimal.

The combination usually causes no specific symptoms. Each drug's individual side effects remain.

At cardioprotective aspirin doses, no adjustment needed. At high anti-inflammatory doses (over 3 g/day) with simultaneous antacid for several days, efficacy may slightly drop — separate dosing by 2 hours.