What are the treatments and medications that are forbidden to prescribe to a patient, with practical examples of those that may be intoxicating?

Among Allah's blessings is that He has provided a cure for every ailment and permitted seeking medical treatment, but He has forbidden treatment with unlawful substances. What intoxicates in large quantities is unlawful even in small quantities, and what is impure is not a medicine but an ailment.

The ruling on medicine containing unlawful or impure substances is detailed as follows: 1. Treatment with purely unlawful or impure substances: Unlawful. 2. Medicine mixed with an intoxicant: If the quantity of the intoxicant is small, such that it does not cause intoxication: Permissible. If the quantity of the intoxicant is large and causes intoxication: Not permissible. 3. Medicine mixed with impure substances (like pig fat): If the impurity undergoes a chemical transformation (istihala) and its properties change to become another substance: Permissible. If the impure substance remains in its original form and does not undergo transformation: Not permissible.

If the unlawful or impure substance loses the characteristics for which it was prohibited, and no trace of its intoxicating or impure nature remains, then its consumption becomes permissible; otherwise, it does not. In ascertaining this, reference should be made to trustworthy pharmacists who are experts in the field.