Most pharmaceutical companies have charitable programs that provide free brand name medications through Patient Assistance Programs (PAP's) 

The programs provide assistance to people who lack prescription drug coverage and demonstrate need by falling within certain income levels.

Annual household income limits are set by each manufacturer and, in general, are set around $20,800 for singles and $28,000 for couples.  Some manufacturers have an income limit as high as $34,000

For a complete list of medications available, click on the link to the left titled Agents List of Medications.  You will find a complete list of medications, the manufacture that produces the medication, the income limits for the particular medication and how it is dispensed.