Which forces are involved in holding the drugs to the active site of enzymes?

Either of the following forces can be involved in holding drugs to the active sites of  enzymes.
(i) Ionic bonding
(ii) Hydrogen bonding
(iii) Dipole − dipole interaction
(iv) van der Waals force

Either of the following forces can be involved in holding drugs to the active sites of enzymes. 

• Ionic bonding
• Hydrogen bonding
• Dipole-dipole interaction
• Van der Waals forces

Forces such as ionic bonding, hydrogen bonding, van der Waals interaction or dipole diple interaction.

Drug is held to the amino acid residues of the protein present on the active site of the enzyme through forces such as ionic bonding, hydrogen bonding, van der Waals’ interaction ordipole diple interaction.