Correlation between serum and salivary phenytoin drug metabolite levels to phenytoin influenced gingival overgrowth in adult male subjects. A prospective cohort study

Scientific rationale: To assess and compare the drug metabolite levels in serum and saliva of a neurologic condition where therapeutic drug concentration is of key importance to minimize the side effects. Principle finding: Saliva could be as useful as serum in deciding the drug concentration of phenytoin. And PIGO is not related drug concentrations. Practical implication: Monitoring the drug dosage is of paramount importance for the success of antiepileptic therapy as well as control of its side effects. This longitudinal study confirms that saliva could be an effective alternative to serum for monitoring drug dosage of phenytoin.