Interchurch Medical Assistance
Serves the needs of short-term, volunteer medical mission teams, including physicians and church-related groups, by providing medicines and medical supplies through its inventory of donated products and the IMA Medicine Box program.
http://imaworldhealth.org  

MAP International
This program offers an assortment of the most critically needed medicines and medical supplies ideal for short-term teams, doctors, nurses and/or church mission groups.      
http://www.map.org