My son,17,has 54.3 hematocrit and 18.3 hemoglobine.is too high?all other values are normal.could it be a sign of use of some sort of drug?

Polycythemia: A hemoglobin of 18.3 is just below the acceptable normal range of 18.5 in a male (some sources consider 18 to be cutoff). Any condition that causes an increase in red blood cell production by the bone marrow will cause an elevated hematocrit. A serious form of this is called poylcythemia vera, other conditions include living in high altitudes, tumors, heart&lung problems, etc.

Not necessarily: Drug use doesn't directly cause your hemoglobin to increase. His levels are a little bit over the normal range but as previously stated, there are numerous causes of elevated H/H. People that abuse illicit substance (if this is what you mean by "drug") can get dehydrated and can be reflected as an elevated H/H, called hemoconcentration.