Three-years' experience of transdermal scopolamine: long-term effectiveness and side-effects.

A study was carried out in 68 otherwise healthy male naval crew members to assess the long-term effectiveness and side-effects of routine transdermal scopolamine administration for the prevention of seasickness. The transdermal patches were applied to the mastoid process before each sailing and the subjects generally used 2 patches a week. Check-ups were made every 3 months over a period of 3 years. The average reported seasickness severity (on a scale of 0 to 7) after 6 months at sea prior to the administration of transdermal scopolamine was 5.64 +/- 0.11 (mean +/- S.E.M.), in comparison with 3.14 +/- 0.23 post-administration (p less than 0.001). A significant improvement was found in the self-estimated performance at sea whilst receiving the drug: 65.7% +/- 3.38% (mean +/- S.E.M.), compared to 25% +/- 2.24% beforehand (p less than 0.001). Contact dermatitis precluded the use of transdermal scopolamine in 3 (4.4%) subjects. The only other significant side-effect was dryness of mucous membranes. In conclusion, transdermal scopolamine was found to be effective in the prevention of seasickness and improvement of performance at sea during 3 years of follow-up and routine administration of the drug was not complicated either by severe side-effects or by performance disturbances.