Restricted sedation and absence of cognitive impairments after administration of intranasal scopolamine.

Introduction: Space motion sickness in astronauts during spaceflight causes significant discomfort, which might impede their functionality. Pharmacological treatment has been mainly restricted to promethazine. Transdermal and oral scopolamine have also been used in space; however, their use was reduced due to unpredictable effectiveness and side effects.

Intranasal scopolamine affects the semicircular canals centrally and peripherally.

Space motion sickness (SMS), a condition caused by an intravestibular conflict, remains an important obstacle that astronauts encounter during the first days in space. Promethazine is currently the standard treatment of SMS, but scopolamine is used by some astronauts to prevent SMS. However, the oral and transdermal routes of administration of scopolamine are known to have substantial drawbacks.

Space motion sickness countermeasures: a pharmacological double-blind, placebo-controlled study.

Introduction: Space motion sickness (SMS), caused by a canal-otolith conflict, is currently treated with intramuscular promethazine. However, the drug has an inconsistent efficacy against SMS. We hypothesize that pharmacological depression of the semicircular canals (SCC) might relieve SMS.

Baclofen affects the semicircular canals but not the otoliths in humans.

Conclusion: This study showed that GABAB agonist baclofen (10 mg) affects the semicircular canals (SCCs), both centrally and peripherally, but does not influence the otolithic function.

Objectives: The aim of the study was to identify the effects of baclofen on the complete vestibular system, i.e.

Pharmaceutical countermeasures have opposite effects on the utricles and semicircular canals in man.

Introduction: Sensory conflicts in the vestibular system lead to motion sickness of which space motion sickness (SMS) is a special case. SMS affects up to 70% of the astronauts during the first 3 days in space. The search for effective countermeasures has led to several nonpharmacological and pharmacological approaches.