What is the ruling on a pharmacist selling medicine when he thinks it most likely that the purchaser is going to use it as a drug or is addicted to it?
Question

I work in a pharmacy, and there are some medicines that are taken by addicts to use for wrongful purposes. When someone comes about whom I have doubts, I lie to him and say that it is not available. Am I sinning for telling this lie? But I am concerned about two things: firstly, that I am giving him the medicine to which he is addicted, so I will have helped someone to take drugs, or if I withhold it from him and he is actually sick, then I will have withheld his medicine from him.
Praise be to Allah.Firstly:
The medicines that are sold in pharmacies are of two types:
-1-
Those which the health authorities have classified as narcotics. They are not to be sold except with a doctor’s prescription, and it is not permissible for the doctor to prescribe them except in the case of extreme need, when there is no permissible alternative available.
The scholars of the Permanent Committee for Ifta’ were asked:
What is the ruling on using pethidine or morphine, which are drugs with a narcotic effect, in the case of necessity or when needed?
They replied: If no other permissible medication is known that could be used to alleviate the patient’s pain except these two medications, it is permissible to use either of them to alleviate pain when necessary. That is so long as no greater or equal harm could result from using them, such as becoming addicted to using them.
Shaykh ‘Abd al-Aziz ibn Baz, Shaykh ‘Abd ar-Razzaq ‘Afifi, Shaykh ‘Abdullah ibn Ghadyan, Shaykh ‘Abdullah ibn Qa‘ud
End quote from Fatawa al-Lajnah ad-Da’imah (25/77-78).
-2-
Those which are not classified as narcotic. In principle, it is permissible to sell them, unless it is known or thought most likely that the purchaser is buying it for some haram purpose, such as intoxication or getting high, because Allah, may He be exalted, says (interpretation of the meaning):
{And cooperate in righteousness and piety, but do not cooperate in sin and transgression. And fear Allah; indeed, Allah is severe in penalty} [al-Ma’idah 5:2].
So if you think it most likely that someone is buying the medicine because he is addicted to it, then you should not sell it to him unless he has a doctor’s prescription.
Secondly:
It is haram to lie except in the case of necessity or in situations in which Islamic teaching grants a concession.
The way out in this case is to use a double entendre. So, for example, you could say, “It is not available,” intending that it is not available to you, or to someone who does not have a doctor’s prescription. Or you could say, “It is not there,” meaning that it is not there on a certain shelf or in a certain section, where this medicine is not usually found.
An-Nawawi (may Allah have mercy on him) said: You should note that what is meant by a double entendre is saying words of which there is an apparent meaning, but you intend another meaning to which these words could also apply, that is different from the apparent meaning. This is a kind of cheating and deceiving. The scholars said that if there is a legitimate purpose to be served that outweighs the sin of deceit, or meets a need that cannot be met except by lying, then there is nothing wrong with using a double entendre. But if that is not the case, then it is disliked, although it is not prohibited, unless it is used as a means to acquire the wealth of others unlawfully or deny them their rights. In that case it is prohibited. This is the guideline regarding this matter."(Al-Adhkaar, p. 380).
See also the answer to question no. 27261 .
And Allah knows best.