The patient should be told to avoid taking supplemental vitamin B6 (pyridoxine ) if he/she being treated with which of the following?
|A||Digoxin for heart failure|
|B||Haloperidol for Tourette’s syndrome|
|C||Levodopa for Parkinson’s disease|
|D||Niacin for hypertriglyceridemia|
Dopa decarboxylase, an enzyme whose activity is dependent on pyridoxine, is responsible for metabolizing orally administered levodopa to dopamine in the gut and that only unmentioned levodopa crosses the blood-brain barrier to be efficacious in relieving Parkinsonian signs and symptoms. that levodopa is often administered with carbidopa, a drug that inhibits the peripheral decarboxylase, sparing levodopa for entry into the brain and whose actions are antagonized by pyridoxine. Administering supplemental B6 will reduce the bioavailability of levodopa, thereby counteracting its antiparkinson effectiveness.