There are a number of medications which can cause psoriasis. One of them is lithium which is being used to treat depression. It has been seen that this medication has aggravated the conditions of psoriasis in almost half of the population affected with psoriasis. Antimalarials like Chloroquine, Plaquenil and Hydroxychloroquin can worsen the flare. After the drug is consumed, the effects will start showing after 2-3 weeks. Inderal which is a popular high blood pressure medicine is known to aggravate the infection of psoriasis.

The conditions have aggravated in 25-30% of the patients. Medicines like Quindine which is mainly used for heart diseases have also worsened the condition of psoriasis. Some other medicines like Indomethacin which is an anti-inflammatory drug used for treating arthritis is known to worsen the condition of psoriasis. The negative effects can be minimal if they are taken in moderate levels. However in most cases it is seen that it is extremely beneficial for psoriatic arthritis.  In some cases it is seen that Interferons which are mainly used for the treatment of Hepatitis C can aggravate the conditions of psoriasis. Often the drug can even prompt the outbreak of psoriasis. Some common medicines like pain relievers for instance ibuprofen, aspirin and amoxicillin can cause flare-ups of psoriasis.