Wof is true regarding tolerance occurring in regular opium abusers
Tolerance and dependence :- High degree of tolerance can be developed to morphine and related opioids if the drug is used repeatedly. It is paly pharmacokinetic (enhanced rate of metabolism), but mainly pharmacodynamic (cellular tolerance). Tolerance is exhibited to most actions, but not to constipating and miotic actions. Addicts tolerate morphine in grams: lethal dose is markedly increased. Ref:- kd tripathi; pg num:-473