Generally speaking, Diltiazem cannot be used together with rifampicin, carbamazepine, cyclosporine and other drugs. 1. Rifampicin: Diltiazem and rifampicin can significantly reduce the plasma drug concentration and efficacy of the product, and should be prohibited from concurrent use. 2. Carbamazepine: Diltiazem combined with carbamazepine can increase the blood concentration of carbamazepine by 40%-72% in some cases and lead to toxicity. 3. Cyclosporine: In cardiac and renal transplant patients, it has been found that there is a synergistic effect when diltiazem is used in combination with cyclosporine, and the dose of cyclosporine should be reduced by 15%-48% to ensure that the drug concentration of cyclosporine is the same as that prior to combining with this product. In addition, Diltiazem also needs to pay attention to the effects of drug interactions when combined with cimetidine, digoxin, and beta-blockers, and it is recommended to use the drug under the guidance of a doctor.