In a rare move, the Justice Department on Tuesday announced that it had charged a former vice president and top lawyer for the British drug giant GlaxoSmithKline with making false statements and obstructing a federal investigation into illegal marketing of the antidepressant Wellbutrin for weight loss. The indictment grabbed the attention of pharmaceutical executives who have been bracing for a long-promised government crackdown on company officials — rather than the corporations themselves — in drug-fraud cases that have resulted in billions of dollars in fines and payments. “This is absolutely precedent-setting — this is really going to set people’s hair on fire,” said Douglas B. Farquhar, a Washington lawyer who recently presided at a panel on law enforcement during a drug industry conference where federal officials warned they were focusing on individuals. “This is indicative of the F.D.A. and Justice strategy to go after the very top-ranking managing officials at regulated companies.”