All are true about levamisole EXCEPT :
Levamisole is an immunomodulator acting as immunostimulant at low doses and immunodepressant at high doses.
It was used as anti-helminthic and causes depolarization by stimulating nicotinic receptors.
It is used for the treatment of colorectal carcinoma in combination with 5-FU.
It is slow to act in psoriasis and requires two-day therapy per week for prolonged periods.