Sulfamethazine

Sulfadimethoxine

1. Combination with urine alkalinizing drugs can enhance the solubility of sulfonamides in alkaline urine and increase excretion. 2. Para-aminobenzoic acid can replace sulfonamides and be taken up by bacteria, antagonizing the antibacterial effect of sulfonamides. Therefore, the two should not be used together. 3. When the following drugs are used in combination with sulfonamides, the latter can replace the protein binding sites of these drugs or inhibit their metabolism, resulting in prolonged drug action or toxicity. Therefore, when these drugs are used in combination with sulfonamides or after the application of sulfonamides, their dosages need to be adjusted. Such drugs include oral anticoagulants, oral hypoglycemic drugs, methotrexate, phenytoin sodium and thiopental sodium. 4. When bone marrow suppressive drugs are used in combination with sulfonamides, the adverse reactions of such drugs to the hematopoietic system may be enhanced. If there is an indication for the combination of the two types of drugs, possible toxic reactions should be closely observed. 5. Contraceptives (estrogens), long-term use with sulfonamides can reduce the reliability of contraception and increase the chance of extramenstrual bleeding. 6. When thrombolytic drugs are used in combination with sulfonamides, their potential toxic effects may be increased. 7. The combined use of hepatotoxic drugs and sulfonamides may increase the incidence of hepatotoxicity. Liver function should be monitored for such patients, especially those who have been taking the drugs for a long time and have a history of liver disease. 8. The combined use of photosensitizing drugs and sulfonamides may cause additive photosensitization. 9. Patients receiving sulfonamide treatment have an increased need for vitamin K. 10. Hexamethylenetetramine can decompose in acidic urine to produce formaldehyde, which can form insoluble precipitates with sulfonamides. This increases the risk of crystalluria, so the two drugs should not be used together. 11. Sulfonamides can replace the plasma protein binding site of phenylbutazone, and when the two are used together, the effect of phenylbutazone can be enhanced. 12. When sulfinpyrazone is used together with sulfonamides, the latter can reduce the latter's secretion from the renal tubules, and its blood concentration increases and lasts for a long time, thus producing toxicity. Therefore, the dose of sulfonamides may need to be adjusted during or after the use of sulfinpyrazone. When the course of sulfinpyrazone treatment is long, the blood concentration of sulfonamides should be monitored to help adjust the dosage and ensure safe use of the drug.

Sulfadimethoxine

1. Combination with urine alkalinizing drugs can enhance the solubility of sulfonamides in alkaline urine and increase excretion. 2. Para-aminobenzoic acid can replace sulfonamides and be taken up by bacteria, antagonizing the antibacterial effect of sulfonamides. Therefore, the two should not be used together. 3. When the following drugs are used in combination with sulfonamides, the latter can replace the protein binding sites of these drugs or inhibit their metabolism, resulting in prolonged drug action or toxicity. Therefore, when these drugs are used in combination with sulfonamides or after the application of sulfonamides, their dosages need to be adjusted. Such drugs include oral anticoagulants, oral hypoglycemic drugs, methotrexate, phenytoin sodium and thiopental sodium. 4. When bone marrow suppressive drugs are used in combination with sulfonamides, the adverse reactions of such drugs to the hematopoietic system may be enhanced. If there is an indication for the combination of the two types of drugs, possible toxic reactions should be closely observed. 5. Contraceptives (estrogens), long-term use with sulfonamides can reduce the reliability of contraception and increase the chance of extramenstrual bleeding. 6. When thrombolytic drugs are used in combination with sulfonamides, their potential toxic effects may be increased. 7. The combined use of hepatotoxic drugs and sulfonamides may increase the incidence of hepatotoxicity. Liver function should be monitored for such patients, especially those who have been taking the drugs for a long time and have a history of liver disease. 8. The combined use of photosensitizing drugs and sulfonamides may cause additive photosensitization. 9. Patients receiving sulfonamide treatment have an increased need for vitamin K. 10. Hexamethylenetetramine can decompose in acidic urine to produce formaldehyde, which can form insoluble precipitates with sulfonamides. This increases the risk of crystalluria, so the two drugs should not be used together. 11. Sulfonamides can replace the plasma protein binding site of phenylbutazone, and when the two are used together, the effect of phenylbutazone can be enhanced. 12. When sulfinpyrazone is used together with sulfonamides, the latter can reduce the latter's secretion from the renal tubules, and its blood concentration increases and lasts for a long time, thus producing toxicity. Therefore, the dose of sulfonamides may need to be adjusted during or after the use of sulfinpyrazone. When the course of sulfinpyrazone treatment is long, the blood concentration of sulfonamides should be monitored to help adjust the dosage and ensure safe use of the drug.