I usually vape 2mg which is nothing, less than one cigarrette but accidentally put 20mg and later got nauseous and felt I was going to relapse and go to the hospital. I am prescribed 8mg risperidone but take 6mg so I took a 2mg as prn and threw away the 20mg nicotine. Back to normal. Never felt this bad since my last relapse over a decade ago. That relapse was caused by stopping meds for 2 years.
3 years ago I was vaping 40mg but did not realise it was bad, maybe my body got used to 2mg then a sudden jump is bad. AI says those who use nicotine have more hospitalization and worse positive symptoms. It reduces antipsychotic efficacy directly via dopamine and indirectly by altering liver enzymes reducing antipsychotic level in the blood.
I vape less than before but need to eliminate it all.