FRANKFORT, Ky. - Pharmaceutical companies that inform physicians about side effects of their drugs cannot be accused of failing to warn the ultimate consumer, the Kentucky Supreme Court said Thursday.

Nor is a drug "unreasonably unsafe," even with side effects, as long as proper warning is given, the justices said in a 4-3 ruling.

The ruling adopted a doctrine to be used in Kentucky in cases involving liability claims against drug companies - a rule under which a manufacturer has satisfied its duty to warn of a drug's possible side effects if it gave a warning to the prescribing physician.

Writing for the majority, Justice William Cooper said he rejected the argument that the rule would make drug companies immune to liability claims.

"Manufacturers still have a duty to warn; the rule only identifies the party to be warned," which is "the health care provider who prescribes the drugs," Cooper wrote.

Absent an adequate warning to the doctor, "the manufacturer is directly liable to the patient," his opinion said.

The ruling was issued in a federal case involving Robert I. Larkin, a paraplegic who allegedly contracted a severe skin condition after taking two drugs - Zithromax, an antibiotic manufactured by Pfizer Inc., and Daypro, an anti-inflammatory drug made by G.D. Searle & Co.

There was testimony at trial that Larkin's condition - toxic epidermal necrolysis - was a side effect of the drugs in rare cases.

There also was testimony that Larkin's physician, Dr. Jeffrey Reynolds of Louisville, knew the condition was associated with Daypro but did not tell Larkin because it was so uncommon. Larkin did not recall a warning on a Zithromax sample package or on his Daypro prescription.

A federal judge ruled in favor of Pfizer and Searle. The 6th U.S. Circuit Court of Appeals asked the state Supreme Court to declare what Kentucky law requires.

Larkin argued that a manufacturer cannot delegate a duty to warn the ultimate consumer. The court's majority said the rule was consistent with Kentucky's "informed consent" law, which was enacted with abortion cases in mind but which anticipates that doctors will inform their patients of risks inherent in any treatment.

In a dissenting opinion, Justice Donald Wintersheimer said the rule made an end run around Kentucky's Product Liability Act and the General Assembly, not the court, should decide whether to adopt it.

An explosion of pharmaceutical advertising aimed directly at consumers "has indelibly changed the realities of physician-patient relationships," Wintersheimer wrote.

And since direct marketing has led to increased sales, "they must also assume (an) increased share in the risks and duties pertinent to selling a product," the opinion said.

Chief Justice Joseph Lambert and Justice Janet Stumbo joined in Wintersheimer's dissent. Justices James Keller, William Graves and Martin Johnstone joined Cooper in the majority.