Does Trimethoprim cause hives?
Patient: Hi I have a 4 month old boy who got diagnosed with bilateral reflux at 7weeks old He has been on trimethoprim since 7 weks old and this week seemed to develop hives how come? Has he become allergic or immune to this antibiotic? We have gone to emerge due to his pedi being away on vacation and they recommend stop and try this new anti called cephalexin for 14 days until I see pedi again what u think I feel my baby is becoming a Ginny pig Doctor: Hello,Trimethoprim can cause hive as a side effect. I agree with your doctor to start another antibiotic. Meanwhile, I suggest using an antihistamines to relieve the hives such as Cetirizine 10 mg.Hope I have answered your question. Let me know if I can assist you further.  Regards, Dr. Dorina Gurabardhi, General & Family Physician