Dr. Peter Bourne, the president's special adviser on health and drug abuse, who resigned yesterday, has given his account of how he came to write a phony prescription for a very powerful drug, and it doesn't bear scrutiny. Still less does it hold up in conjunction with the statement issued by his assistant, Ellen Metsky, for whom the drug was allegedly intended. It is now up to the authorities to decide what laws and regulations may have been violated.

On its face, what has been conceded justifies his leaving the White House and, in particular, his leaving a job that has to do with government policy on drug abuse. What Dr. Bourne did represents a serious, unaccountable lapse of judgement - at best. And there are enough questions raised and oddities unexplained in the formal accounts to suggest that something other than the "best case" version is in store.

So the White House and Dr. Bourne have done the right thing in arranging his departure, and they have done so with appropriate dispatch.

Dr. Bourne had made a reputation for long service to President Carter and deep concern for the problems with which he dealt while on the White House staff. Our sympathy for the unhappy end of his government career is tempered, however, by the over-wrought and overbearing quality of his letter of resignation to the president. Whatever may be involved in this matter, it can in no way be seen as Dr. Bourne portrayed it in his letter to Mr. Carter - as an attempt by law-enforcement of media figures to "hurt you through my disparagement." We are prepared to believe that Dr. Bourne's behavior was in some ways occasioned by the heavy strains and pressures of White House service. But that cannot alter the basic fact that if anyone has hurt the president in this matter, it is quite simply and exclusively Dr. Bourne.