Dizziness modafinil

Clozapine toxicity occurred in a 42-year-old man after he was given modafinil 300 mg/day, a central stimulant, to combat sedation associated with clozapine (450 mg/day) (260). He complained of dizziness, had an unsteady gait, and fell twice. His serum clozapine concentration was 1400 ng/ml, which suggested a metabolic interaction between clozapine and modafinil. The authors suspected that inhibition of CYP2C19 by modafinil had reduced clozapine clearance. 

In an open, randomized, crossover study in healthy men, concomitant administration of single oral doses of modafinil (200 mg) and dexamfetamine (10 mg), each given separately, produced a slight increase in blood pressure and the cardiovascular effects were more pronounced after concomitant administration (3). These changes were considered not to be clinically relevant and would not necessarily preclude shortterm administration of the two drugs together. The most frequent adverse events with modafinil or dexamfetamine were headache, dizziness, insomnia, and dry mouth. 

---