Is it permissible to use IUD for 5 years and 8 years?

All praise be to Allah and may His peace and blessings be on His final and greatest messenger, Muhammad.

The default principle is that fertility is a blessing and Muslims should aim to have large families. This is due to the saying of Allah’s Messenger (Allah's peace and blessings be upon him):

"تزوجوا توالدوا تناسلوا فإني مباه بكم الأمم يوم القيامة."

“Marry and re-produce, for I will be proud of you on the Day of Resurrection.”

It is a given that this is recommended within man’s capacity. If there is a reason for birth control, such as the mother’s weakness or her inability to look after the various needs of more kids, then it is allowable to have some planning. Jabir ibn Abdillah said:

"كنا نعزل والقرآن ينزل."

“We used to practice coitus interruptus while the Quran was descending.”

In light of the aforementioned principles, the use of IUDs is one of the better ways for birth control because of the lack of the side effects. The only drawback, according to some, would be the uncovering of the ‘awrhah (one’s nakedness) without a necessity or a significant need. It is however permissible according to the majority of modern scholars for this purpose, and the need is not insignificant. The duration of use is non-consequential in this regard.

To summarize, whenever birth control is indicated, the use of IUDs is preferred medically and consequently it would be preferred islamically.

Allah knows best.