Bhang vs. liquor
"Does talaq pronounced in a state of intoxication throw out the wife? Well, the matter turns first of all the substance by taking which the husband has got intoxicated. If it is hemp (bhang) then, hold several jurists as well as law books like Fatawa-i-Qazi Khan, the pronouncement does not end the marriage. They give two sorts of reasons for this view: they reason first that, while liquor is prohibited by Islam and therefore a man consuming it ought to be made to suffer the consequences of his action, bhang is not prohibited and so such a severe punishment – of the man losing his wife – should not be visited upon him; second, they reason that as a divorce pronounced by a man bereft of understanding – a minor, a lunatic – is not effective, talaq pronounced by a man who has temporarily lost his understanding because of bhang is not to be given effect to. But other law books – Fatawa-i-Alamgiri being the foremost – argue the opposite: consumption of bhang too has become so widespread, they say, that it too needs to be discouraged and therefore, divorce pronounced under its influence, exactly like that under the influence of liquor, is to be final. Another law book – Al-Bahr Al-Raiq – goes in for finer differentiation: if bhang has been taken for pleasure, the divorce is effective; if it has been taken as a medicine, it is not.'
"What if the husband is intoxicated not from bhang, but from liquor? Does talaq pronounced in that state throw out the wife? The law varies over the entire spectrum – from 'No, never,' through 'Depends,' to 'Yes, invariably' – and the distinctions which the Islamic jurists make are fine as can be."
(pp. 430-1, 'The World of Fatwas or the Shariah in Action' by Arun Shourie – Harper)