What is the ruling on using "Entonox" pain-relieving gas for pregnant women during childbirth, which causes dizziness after inhalation, given that it does not contain any forbidden substances?

There is no objection to using "Entonox" gas to relieve labor pains. It is a gas composed of oxygen and nitrous oxide that the pregnant woman inhales to alleviate the intensity of contraction pains. The general rule is that anything that removes the intellect is forbidden, but exceptions are made for what is necessitated by need, such as anesthesia and the like. This is the view held by Sheikh al-Islam Ibn Taymiyyah, al-Hattab al-Maliki, al-Nawawi, and Ibn Rajab al-Hanbali. The Permanent Committee has issued a fatwa permitting the use of medicinal intoxicants when necessary to alleviate pain if no other permissible substances are available, and provided that no greater harm results from their use.