Therapeutic level of phenytoin is: (A) 0-9 mg/ml, (B) 10-19 mg/ml, (C) 20-29 mg/ml, (D) 30-39 mg/ml
Answer is B. Phenytoin therapeutic plasma concentration is 10-20 mg/ml. Ref: K D Tripati 7th edition Page no 422. Table 30.2