A 43-year-old female with past medical history of attention deficit hyperactivity disorder of inattentive type, depression, chronic pain syndrome, and diabetes mellitus presented to sleep disorder center for evaluation of excessive daytime sleepiness (EDS). She denied consumption of cigarettes, alcohol or recreational drugs. Her home medications included Metformin, Gabapentin, Bupropion, Venlafaxine, Buspirone and Methylphenidate. General physical exam was consistent with crowded oropharynx, (Mallampati class 3 with grade 1 tonsils), but a normal cardiovascular as well as neurologic exam. She underwent attended diagnostic in laboratory polysomnogram (PSG) which revealed OSA with an apnea hypopnea index (AHI) of 9.3 events/hour, and oxygen nadir of 90%. Her percentage of total sleep time (TST) in non-rapid eye movement sleep in stage 3 (N3) increased from 15.3% in diagnostic PSG to 58.1% in titration study and up to 86.3% in re-titration study.
Her titration study was done two weeks following diagnostic PSG and a continuous positive airway pressure (CPAP) setting of 6 cm of water was recommended. She had a re-titration study 9 months later due to CPAP intolerance and lack of significant improvement in OSA symptoms. This re-titration study recommended a bi-level positive airway pressure (BiPAP) of 12/7 cm of water. The patient was started on Gabapentin 900 mg daily 2-3 months prior to her re-titration study. Other than initiation of Gabapentin, no changes occurred in terms of her body weight, clinical comorbidities or use of prescription/nonprescription medications between subsequent sleep studies.