## Facts

- Lydia Basko was treated for lupus erythematosus from about 1953 to 1961 with three prescription drugs manufactured by Sterling Drug/Winthrop: Aralen, Atabrine, and Triquin.
- The drugs contained chloroquine or closely related compounds.
- In 1956, after years of therapy, Basko developed blurred vision that progressively worsened until she was almost completely blind.
- Basko alleged the drugs caused toxic retinal injury and that Sterling failed to provide adequate warnings of serious ocular risks.
- Evidence indicated that by the mid-1950s there were publications reporting visual disturbances associated with chloroquine use and experimental evidence of retinal effects in animals.
- Sterling conceded awareness of reports of blurred vision in chloroquine-treated patients but argued that reports specifically describing retinal damage did not appear until about 1957.
- Basko took Triquin from about 1959 to 1961, after more serious ocular effects were discussed in medical literature.
- In 1962, Sterling updated product information for Aralen and Triquin to warn that retinal changes, although rare, could occur.
- Basko presented expert testimony that her blindness was most likely caused by chloroquine-based drugs and that Aralen and Triquin contained chloroquine or closely related ingredients.

## Issues

1. Whether prejudicial errors in jury instructions and evidentiary rulings on warnings, causation, and medical literature required a new trial.
2. Whether, under Connecticut law, a prescription drug manufacturer satisfies its duty to warn by warning the prescribing physician rather than the patient.
3. Whether the jury was properly guided on causation where multiple related drugs were used over time and medical knowledge developed during the treatment period.

## Decision

- The Second Circuit reversed the defense judgment and remanded for a new trial.
- The court accepted the learned-intermediary approach: the manufacturer’s duty to warn is directed to the prescribing physician, not directly to the patient.
- The court held that the combination of instructional error and restrictive handling of evidence concerning medical knowledge and warnings was sufficiently prejudicial to warrant a retrial.

## Legal Principles

- In prescription drug cases governed by Connecticut law, the manufacturer generally discharges its duty to warn by providing adequate warnings to the prescribing physician, who applies independent medical judgment for the patient.
- The adequacy and timing of warnings to the medical profession are ordinarily fact questions for the jury when the evidence permits competing conclusions.
- Evidence of the state of medical and scientific knowledge at the relevant time, including published literature and the manufacturer’s awareness of it, is materially relevant to whether warnings were reasonable and adequate.
- Where causation involves multiple drugs and a developing medical-knowledge timeline, jury instructions must clearly frame how the jury should evaluate whether one drug, more than one drug, or later usage contributed to the injury.

## Conclusion

The court ordered a new trial because the jury’s defense verdict was reached under instructions and evidentiary limitations that did not fairly present the warning-adequacy and causation questions in light of evolving medical knowledge, while reaffirming that prescription-drug warning duties ordinarily run to physicians as learned intermediaries.


Basko v. Sterling Drug, Inc., 416 F.2d 417 (2d Cir. 1969)