SAFE — No Known Interaction
🟢 SAFE — Trimethoprim-Sulfamethoxazole and Vitamin B3 can be taken together safely.
Evidence level: MODERATE
Trimethoprim-Sulfamethoxazole and Vitamin B3 are generally considered safe to use together. No adverse interactions have been reported in medical literature.
No clinically significant interaction between Trimethoprim-Sulfamethoxazole and Vitamin B3 has been identified in medical literature.
No interaction documented between Trimethoprim-Sulfamethoxazole and Vitamin B3. Always inform your healthcare provider about everything you take.
Space Vitamin B3 at least 2 hours from Trimethoprim-Sulfamethoxazole. Fat-soluble vitamins (A, D, E, K) should be taken with a fatty meal. Vitamin K can counteract certain antibiotics' effect on gut flora vitamin K production. Vitamin C may acidify urine, affecting some antibiotic excretion rates.
Higher risk for: those with liver or renal impairment, elderly, concurrent use of nephrotoxic or hepatotoxic drugs, history of C. difficile infection, or those on narrow therapeutic index medications (warfarin, digoxin).
Monitor for altered effectiveness and side effects when combining Trimethoprim-Sulfamethoxazole with Vitamin B3. Antibiotics can affect liver enzymes and alter the blood levels of other medications. Watch for: unusual nausea, vomiting, diarrhea (especially watery or bloody), stomach cramps, skin rash, dizziness, or signs the other medication is working differently than usual. When to seek emergency help: Severe allergic reaction (difficulty breathing, swelling of face/throat, hives), severe or persistent diarrhea (possible C. difficile infection), yellowing of skin or eyes, dark urine, or irregular heartbeat. Complete the full antibiotic course as prescribed.
No urgent discussion needed, but keep your provider informed. Say: "I take Trimethoprim-Sulfamethoxazole alongside Vitamin B3 — anything I should know?"
Safe combination at standard doses. Continue your medication as prescribed. Inform your doctor or pharmacist that you are using both, so they can monitor for any changes over time.
Trimethoprim-Sulfamethoxazole and Vitamin B3 are generally considered safe to use together. No adverse interactions have been reported in medical literature.
Space Vitamin B3 at least 2 hours from Trimethoprim-Sulfamethoxazole. Fat-soluble vitamins (A, D, E, K) should be taken with a fatty meal. Vitamin K can counteract certain antibiotics' effect on gut flora vitamin K production. Vitamin C may acidify urine, affecting some antibiotic excretion rates.
Monitor for altered effectiveness and side effects when combining Trimethoprim-Sulfamethoxazole with Vitamin B3. Antibiotics can affect liver enzymes and alter the blood levels of other medications. Watch for: unusual nausea, vomiting, diarrhea (especially watery or bloody), stomach cramps, skin rash, dizziness, or signs the other medication is working differently than usual. When to seek emergency help: Severe allergic reaction (difficulty breathing, swelling of face/throat, hives), severe or persistent diarrhea (possible C. difficile infection), yellowing of skin or eyes, dark urine, or irregular heartbeat. Complete the full antibiotic course as prescribed.
Safe combination at standard doses. Continue your medication as prescribed. Inform your doctor or pharmacist that you are using both, so they can monitor for any changes over time.
No urgent discussion needed, but keep your provider informed. Say: "I take Trimethoprim-Sulfamethoxazole alongside Vitamin B3 — anything I should know?"
Or browse the full interaction database (121,000+ pairs).