Clinical pharmacology and toxicology of antidepressants.

Described as the drugs of choice in treating acute depression, the tricyclics are unusual in that too high a dosage may be as ineffective as one that is too low, and plasma levels may vary as much as 30-fold among patients given the same dosage. After the recommended approach to determining appropriate dosage has been tried, the 15% or so of patients who do not respond are not likely to benefit from a switch of drugs.