Delta-9-tetrahydrocannabinol and cannabidiol: Separating the chemicals from the "weed," a pharmacodynamic discussion.

Cannabis is being increasingly used as a medical treatment for a variety of illnesses. However, the cannabis plant has more than 70 different phytocannabinoids with potential pharmacologic activity. Two of the most researched phytocannabinoids are delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Evidence suggests CBD can decrease some of the psychomimetic effects of THC. This has led to the development of a new drug, Nabiximols, for the treatment of moderate to severe spasticity due to multiple sclerosis. A discussion of evidence supporting proposed pharmacodynamic interplay between CBD and THC is presented.

Adverse drug reactions in hospitalized psychiatric patients.

BACKGROUND: Reducing adverse drug reactions (ADRs) is a critical element in providing safe medication use to hospitalized patients. There is an abundance of literature describing ADRs and preventable ADRs (pADRs) in hospitalized patients; however, little has been published specific to psychiatric inpatients. Further knowledge of the most common pADRs in hospitalized psychiatric patients will allow targeted patient safety initiatives to be developed. OBJECTIVE: To determine the most frequent ADRs and pADRs in a psychiatric hospital, with emphasis on identifying factors for prevention. METHODS: Three years of ADRs at a psychiatric hospital were analyzed and evaluated according to type of medication, preventability, severity, and factors associated with preventability. RESULTS: From July 1, 2006, to June 30, 2009, 93 ADRs were reported; 19 (20.4%) were classified as preventable. Psychiatric medications accounted for 45 (48.4%) of the ADRs and nonpsychiatric medications were associated with 48 (51.6%). Cardiovascular agents (n = 17) and antiepileptics (n = 17) were responsible for most ADRs. Of the 19 pADRs, lithium was the drug reported most frequently, followed by phenytoin and anxiolytics. Nine (47%) of the pADRs were severe and required a medical transfer for management; 3 of the 9 were lithium toxicity. The most common preventability factor involved drug interactions. A pharmacy intervention involving staff education to reduce lithium pADRs is presented. CONCLUSIONS: Awareness of the most frequent drug classes associated with ADRs and pADRs in a psychiatric hospital allows opportunity for education, medication management system changes, and improved patient safety. Lithium, followed by phenytoin and anxiolytics, were the most common drugs associated with pADRs. A drug-drug interaction was the most frequent factor associated with pADRs.

Efficacy of add-on topiramate therapy in psychiatric patients with weight gain.

BACKGROUND: Weight gain is a common adverse effect of many psychotropic medications including antipsychotics, antidepressants, and mood stabilizers. There is a growing body of evidence that topiramate may be useful as an add-on therapy to induce weight loss in patients who have experienced psychotropic-induced weight gain. OBJECTIVE: To determine the efficacy and tolerability of topiramate for treatment of weight gain in a naturalistic mental health clinic setting. METHODS: A retrospective chart review was conducted at a community mental health clinic. Subjects were non-elderly adults who received topiramate therapy beginning in 2002-2005 for documented weight gain during treatment with psychotropic drugs. Primary outcome measures included response rate (based on weight loss of any magnitude) and mean changes in weight and body mass index (BMI). RESULTS: Forty-one patients were included in the study. There was a 58.5% (n = 24) response rate. Mean reductions in weight and BMI were approximately 2.2 kg and 0.5 points, respectively. Responders lost an average of 7.2 kg, whereas nonresponders gained an average of 5.0 kg. Patients with a baseline weight of at least 91 kg and those receiving a greater number of psychotropic medications were more likely to experience success with topiramate therapy. Of the 24 patients who responded to therapy, 22 experienced onset of weight reduction by the next clinic visit (1-4 mo) following either initiation of therapy or titration to the eventual therapeutic dose, and the usual rate of weight loss was 0.45-1.4 kg per month. Therapy was typically initiated at 50 mg/day. The mean maximum dose was 93.9 mg/day and the median maximum dose was 100 mg/day. Seven (17.1%) patients had documented adverse effects to topiramate therapy. CONCLUSIONS: Topiramate therapy resulted in overall modest (ie, <2%) decreases in weight and BMI, but many patients experienced more impressive weight loss. Therapy was generally well tolerated.