Dose range: 100 to 450 mg/day. IV route: three doses of 5 mg Metoprolol administered at intervals of 2 minutes time. Oral route: if the patient gives no sign of complication from the IV route, a total of 15 mg, then a tablet of 50 mg in 6 hour block should start immediately after the IV dose.
â¢ ANTIHISTAMINE (noun) The noun ANTIHISTAMINE has 1 sense: 1. a medicine used to treat allergies and hypersensitive reactions and colds; works by counteracting the effects of histamine on a receptor site. Familiarity information: ANTIHISTAMINE used as a noun is very rare.
Antihistamines are drugs that block the action of histamine (a compound released in allergic inflammatory reactions) at the H1 receptor sites, responsible for immediate hypersensitivity reactions such as sneezing and itching.