What is the mediine for hives?

Antihistamines. Hives can be treated with otc antihistamines like benadryl, (diphenhydramine) zyrtec. They tend to resolve once the trigger has abated. Anything prolonged >3 days must be examined by a medical professional.
Antihistamines. Like Diphenhydramine [generic benadryl], anti-itching steroid cream like hydrocortisone. Think about what's new and different before your hives started. Any new foods? Drugs/herbs/supplements? New body products/soap? New detergents/fabric softeners? Talk to your doc right away if your lips are swelling or you have trouble breathing/swallowing. Good luck finding your triggers. Hope you feel better.
An anti-histamine. Hives are raised, itchy bumps caused by histamine, a chemical released during an allergic reaction. Blocking histamine by taking an oral anti-histamine will help prevent new hives from forming, and help current hives fade away. For young toddlers, Benadryl (diphenhydramine) liquid is often used. For kids over 2 years, oral zyrtec or Claritin can also be used. Sometimes, Hydrocortisone 1% cream can decrease hives.