Aspirin in Kawasaki disease is given both for its anti inflammatory effect and antiplatelet effect. In the early stage it is for anti inflammatory effect while later it is for antiplatelet effect in case of coronary artery involvement. Anti inflammatory dose is high in the range of 80 to 100 milligrams per kilogram body weight and is given for only a short period. Only low dose in the range of three to five milligrams per kilogram body weight is needed for antiplatelet effect and is given for a longer period.
Aspirin – ibuprofen interaction
Ibuprofen can interfere with the antiplatelet effect of low dose aspirin and should be avoided in children needing low dose aspirin for its antiplatelet effect as with coronary aneurysms in Kawasaki disease.
Reye syndrome with aspirin
Reye syndrome is a potentially fatal situation with involvement of brain and liver which can occur in children on aspirin when they develop influenza or varicella. It has been reported in children taking high dose aspirin for a prolonged period in Kawasaki disease. But it is not clear whether low dose aspirin given for antiplatelet effect in case of coronary aneurysms also predisposes to Reye syndrome. Similar concerns over Varicella vaccination has also been raised as manufacturers recommend avoiding aspirin for 6 weeks after vaccination. Substitution with other antiplatelet agents during this period has been suggested. Parents of children on long term aspirin should be advised to contact their physician if they develop influenza or varicella or even gets exposed to these illnesses.