Found this searching the web:
Mr. Chakib Mzah
Chief, Department of Common Services, ONFP, Tunisia
I. Drug regulatory
The legislation of Drugs in Tunisia, obeys to international medicine norms (classification, distribution, supplying, sale, etc), it is similar to the French legislation.
I'd interpret that to mean that you'd need a prescription. Of course, in poor countries it isn't hard to find a doctor willing to write whatever prescription you want for a few American $s. As far as what might be available, who knows....