A 46-year-old man presents to the clinic with his wife, who is concerned that he is spending excessive time “checking things.” The patient reports a 6-month history of repeated checking behaviors involving locks, appliances, and light switches before leaving home and before going to bed. He estimates he spends at least 2 hours a day on these behaviors, which cause him to be late for work and have led to conflict in his marriage. He reports intrusive thoughts that his house will burn down or be broken into if he does not complete these rituals. He recognizes these thoughts and behaviors are excessive but feels unable to resist them. He has no history of hallucinations, delusions, or substance use. Past medical history is unremarkable. His mother has a history of generalized anxiety disorder. Vital signs are within normal limits. A mental status examination reveals he has an anxious mood, but lacks psychosis and cognitive defects.
Which of the following is the most appropriate pharmacologic treatment for this patient’s condition?
C) Fluoxetine
This patient has obsessive-compulsive disorder (OCD), characterized by obsessions (intrusive thoughts) and compulsions (ritualistic behaviors performed to reduce anxiety). First-line pharmacologic treatment is a selective serotonin reuptake inhibitor (SSRI) such as fluoxetine, fluvoxamine, or sertraline, often combined with cognitive-behavioral therapy.
Answer choice A: Buspirone, is incorrect. Buspirone works as a serotonin 5-HT1A receptor partial agonist and is an anxiolytic used for generalized anxiety disorder (GAD). Buspirone has no proven benefit in treating OCD, which requires serotonergic modulation via an SSRI.
Answer choice B: Clonazepam, is incorrect. Clonazepam is a long-acting benzodiazepine used for anxiety and panic disorders. Benzodiazepines are not first-line therapy for OCD and carry risks of tolerance, dependence, and withdrawal. They are generally reserved for short-term adjunctive use in severe anxiety.
Answer choice D: Haloperidol, is incorrect. Haloperidol is a typical (first generation) antipsychotic used for schizophrenia and agitation associated with psychiatric disorders, substance intoxication, or organic causes. Antipsychotics may be added to SSRIs in treatment-resistant OCD, but they are not first-line therapy, and a second-generation antipsychotic would be preferred.
Answer choice E: Lithium, is incorrect. Lithium is a mood stabilizer primarily used for bipolar disorder. Lithium has no role in the treatment of OCD and would not address the patient’s obsessive-compulsive symptoms.
Key Learning Point
OCD is characterized by obsessions and compulsions. OCD is best treated with an SSRI and/or cognitive-behavioral therapy.
