Cannabis Dopaminergic Effects Induce Hallucinations in a Patient with Parkinson's Disease.

Cannabis products that contain the tetrahydrocannabinol (THC) cannabinoid are emerging as promising therapeutic agents for the treatment of medical conditions such as chronic pain. THC elicits psychoactive effects through modulation of dopaminergic neurons, thereby altering levels of dopamine in the brain. This case report highlights the complexity associated with medicinal cannabis and the health risks associated with its use. A 57-year-old male with Parkinson's disease was experiencing worsening tremors and vivid hallucinations despite therapy optimization attempts. It was discovered that the patient took cannabis for chronic back pain, and a pharmacogenomics (PGx) test indicated the presence of variants for the COMT and HTR2A genes. These variants could increase dopamine levels and predispose patients to visual hallucinations. Once the cannabis was discontinued, the patient's hallucinations began to slowly dissipate. Cannabis use continues to expand as it gains more acceptance legally and medicinally, but cannabis can affect the response to drugs. This patient case suggests that cannabis use in combination with dopamine-promoting drugs, especially in a patient with genetic variants, can increase the risk for vivid hallucinations. These conditions support the importance of considering herb-drug interactions and PGx data when performing a medication safety review.

Utilizing Pharmacogenomics Results to Guide Antidepressant Selection: A Case Report.

The case discussion demonstrates the benefit of using Pharmacogenomic (PGx) results to aid in the selection of antidepressant therapy and improve response to treatment. Nearly half of patients diagnosed with major depressive disorder fail initial therapy and may require multiple trials of antidepressants. Genetic variation in several metabolic enzymes contribute to the variable response to antidepressant therapy. PGx testing provides an opportunity to inform antidepressant selection and optimize therapeutic outcomes, while minimizing risk of adverse events. A 79-year-old female who had been experiencing a suboptimal response to escitalopram following dose escalation over a period of three years was referred for a PGx consultation. A clinical pharmacist assessed significant drug-gene, drug-drug, and drug-drug-gene interactions, and relevant clinical information to recommend alternative antidepressant therapy, which resulted in mood improvement.