Pharmaceuticals giants AstraZeneca and GlaxoSmithKline denied aggressively pushing their products onto Britain's health system or suppressing negative research on new drugs.
Under cross-examination from parliament's Health Select Committee, executives from both companies said a new climate in Britain - with the public demanding more information and transparency, and the media looking for the next big medical story - made for a tough working environment.
The cross-party committee is inquiring into the industry's influence on healthcare, research and the prescription and use of medicines in Britain. It aims to report in March.
"Uptake of new medicines in Britain is one of the slowest in western Europe," said Mr Eddie Gray, general manager of GlaxoSmithKline's UK arm.
"Things seem to have gone completely out of balance in terms of public perceptions," Mr John Patterson, executive vice-president of Anglo-Swedish group AstraZeneca said. "Things are either wonder cures or killer medicines."
He echoed Mr Gray, saying Britain only adopted new medicines at about the same rate as Croatia. Last week, the global drugs industry unveiled a new industry-wide code to publish more data about clinical trials of medicines in a bid to reassure patients following recent alarms over drug safety.
Controversy about drug companies concealing research, either to prevent rivals from learning too much or because negative results would hit sales, has been simmering for years.
New York Attorney General Eliot Spitzer brought the issue to a head last year by accusing GlaxoSmithKline of fraudulently suppressing important information about the use of its antidepressant Paxil, or Seroxat, in children.
The committee pressed for answers on Seroxat and the withdrawal symptoms it inflicted on some users. Mr Stuart Dollow, medical director of GlaxoSmithKline UK, said his company published the results of all its studies on all drugs "whether negative or positive".
Mr Patterson of AstraZeneca said licences for drugs were only granted on "the totality of the evidence", but said side effects could not be viewed in isolation and must rather be balanced against the benefits a drug brought. "People are not well versed in talking about relative risk," he said.
The parliamentarians quizzed the executives on the use of "ghost writers", where big-name experts are enticed to put their name to papers covering research with which they had little or no involvement. Both companies rejected the practice out of hand.
Mr Patterson did admit that professional writers, who were not medical experts, were used to draft articles for the media.
Neither company asked for "direct to consumer marketing" of prescription drugs in Britain, as allowed in the United States but said they had to be able to get information across to the public, not least to counter some content on the Internet.