Is it permissible for a cancer patient receiving intravenous treatment to fast in Ramadan?

Receiving injections during the day in Ramadan has two scenarios: If the injection is nourishing and substitutes food and drink, then it invalidates the fast. If it is not nourishing, then it does not invalidate the fast.

Sheikh Ibn Baz said: The fast of one who receives an injection, whether intravenously or intramuscularly, is valid, because it is not of the nature of eating and drinking. However, it is preferable to make up for it as a precaution, and delaying it until night is better.

Sheikh Ibn Uthaymeen said: Injections given intravenously, intramuscularly, or in the hip do not invalidate the fast of the fasting person, because they are not among the things that invalidate the fast and are not considered to be in the meaning of eating and drinking.

The Permanent Committee stated: It is permissible for a fasting person to receive intramuscular and intravenous injections for treatment. However, it is not permissible to receive nourishing injections because they are considered to be in the ruling of consuming food and drink. It is better to receive injections at night if possible.