The State Department's Bureau of Consular Affairs recommends that, once abroad, you should check with local authorities or at the Consular Section of the nearest U.S. embassy or consulate. For example, in Japan there is no appreciation of the rights guaranteed to American citizens by the Fourth, Fifth, Sixth, Seventh, and Eighth Amendments to the Bill of Rights. Among other things, Japanese police can search citizens at will, an arrested suspect can be detained without bail for up to 28 days before a prosecutor must bring him before a judge, and suspects who insist on standing trial do not have a right to a jury. About 3,000 Americans are arrested abroad each year. Of these, approximately one-third are held on drug charges.
Many countries have stiff penalties for drug violations and strictly enforce laws.
Americans are subject to foreign, not United States, laws overseas, and you have no U.S. constitutional rights. Drug convictions can result in life imprisonment or the death penalty in some countries. Persons required to take medication containing narcotic drugs should carry a doctor's certificate attesting to the fact and should keep medicines in their original and labeled containers. Commonly used medications such as amphetamines, barbiturates, codeine, captagon, and many other substances that are not considered drugs in the United States may be considered drugs elsewhere. Unless you are rich and powerful, there is little that a U.S. consul can, or wants to, do for you if you encounter legal difficulties.