A selective literature review exploring the role of the nicotinic system in schizophrenia

Nicotine use is more prevalent in patients with psychiatric disorders, especially those diagnosed with psychotic illnesses. Previously, this higher prevalence has been partially attributed to the potential ameliorative effects of nicotine on symptom severity and cognitive impairment. Some healthcare professionals and patients perceive there is a beneficial effect of nicotine on mental health. Emerging data show that the harm associated with nicotine in the population of patients with mental health conditions outweighs any potential benefit. This paper will review the evidence surrounding the nicotinic system and schizophrenia, with a focus on any causality between nicotine and psychosis.

Cannabis legalisation: should doctors be concerned?

A referendum on the Cannabis Legalisation and Control Bill was held in New Zealand. The Bill was meant to oversee government control over the production, supply and use of cannabis and reduce cannabis-related harm. Public health control was proposed over cannabis market by imposing licenses and cultivation, the quality and strength of marketed cannabis, and sale restrictions. Under this Bill, cannabis was only meant to be available to adults aged over 20 years through licenced stores. The potency of cannabis was to be limited. Cannabis use and was going to be permitted in private homes and specifically licensed premises. The Electoral Commission announced on 6 November 2020 that 50.7% of voters opposed the Bill and 48.4% supported it. Despite the outcome of the referendum, legalisation of cannabis may remain a live issue for many people, and doctors need to have an informed view about the impact of legalisation on mental health conditions. Experience from other countries shows that access to and potency of cannabis increased with legalisation. Despite the intent to prevent harm, cannabis legislation has been associated with adverse effects on mental health, emergency hospital presentations and crime. Public health strategies, including educating public about harm associated with cannabis, surveillance of potency and labelling, increasing minimal age for legal recreational cannabis use and bolstering treatment capacity for problematic cannabis use, including those with psychiatric disorders, should be funded by revenue generated from cannabis legislation.

E-cigarettes and vaping - a panacea or a bane to smoking in current times?

OBJECTIVE

Use of electronic cigarettes has increased across the world in the last decade with heavy investment from the tobacco industry targeting younger population through well-designed marketing campaigns portraying e-cigarettes as harmless, less addictive and effective in smoking cessation while delivering higher nicotine concentration. The safety profile of e-cigarettes is reviewed in this paper.

CONCLUSIONS

The safety of e-cigarettes and the chemicals they contain have not been evaluated rigorously. Emerging data suggest e-cigarette use could do severe harm. People with serious mental illness, already the highest nicotine consumers, could be exploited by the tobacco industry.

Clozapine associated cardiotoxicity: Issues, challenges and way forward

OBJECTIVE

To review the published literature on clozapine associated cardiotoxicity (CACT), summarize diagnostic features, and evaluate monitoring procedures for safe clozapine re-challenge.

RESULTS

Clozapine-associated Myocarditis (CAM) - Incidence of early myocarditis (≤2 months) is infrequent but serious. Clinical diagnosis is confounded by variability in presentation and non-specificity of symptoms. Re-challenge considerations include clozapine impact on symptomatic severity and associated disability and risk of suicidality. Re-challenging is recommended only after full clinical resolution of myocarditis and cardiac function impairment, under closely controlled conditions, starting at very low dosage, extremely slow titration and frequent assays of lab and cardio biomarkers. Clozapine associated cardiomyopathy (CAC) -develops later but mortality has been reported at 12.5-24.0%. Re-challenge is generally not recommended due to paucity of outcome data. Monitoring Cardiac Toxicity: Plausible steps include closer clinical monitoring, repeated assays of biomarkers, and echocardiographic studies, and cardiac MRI changes with unremarkable findings of cardiac dysfunction with echocardiography. Subclinical clozapine associated cardiotoxicity is more prevalent than CAM and CAC. Diagnosis is often challenging due to non specific presentation. Active monitoring is recommended. Rechallenging is feasible but should be done under close monitoring conditions. A protocol is proposed based on literature review and clinical experience in order to reduce the risk of CACT.

CONCLUSION

Clozapine-associated myocarditis and cardiomyopathy may have been underreported worldwide. Identification of subclinical cardiotoxic effects can improve outcomes by earlier recognition before clinical manifestations of cardiac impairments. A pragmatic close clinical monitoring protocol including cardiac biomarkers aimed at timely detection of cardiac toxicity, in the initial phase of treatment is proposed.