Another kind of systemic drug also targets your immune system. Biologic drugs used to treat psoriasis include adalimumab (Humira), brodalumab (Siliq) infliximab (Remicade), ixekizumab (Taltz), secukinumab (Cosentyx), and ustekinumab (Stelara). They're given either by a shot or through a vein in your arm. They affect a specific type of immune cell or keep certain proteins from causing inflammation. But these drugs can make it harder for you to fight an infection.