The H2-antagonists, cimetidine and ranitidine: studies on performance

Area of Science:

• Pharmacology
• Neuroscience
• Human Performance

Background:

• Cimetidine and ranitidine are H2 receptor antagonists used to reduce stomach acid.
• Potential central nervous system (CNS) effects of these medications are not fully understood.
• Assessing cognitive and psychomotor function is crucial for medication safety in daily activities.

Purpose of the Study:

• To evaluate the effects of cimetidine and ranitidine on cognitive and psychomotor performance.
• To compare the safety profile of these H2 antagonists with an active control (triprolidine).
• To determine if these medications impair performance in skilled activities.

Main Methods:

• Double-blind, placebo-controlled study with seven healthy female volunteers.
• Administration of single oral doses of cimetidine (200, 400 mg) and ranitidine (150, 300 mg).
• Assessment of visuo-motor coordination, dynamic visual acuity, digit symbol substitution, symbol copying, critical flicker fusion, and subjective mood using triprolidine (10 mg) as an active control.

Main Results:

• Cimetidine and ranitidine did not cause adverse effects on performance, CNS function, or mood.
• Triprolidine significantly impaired visuo-motor coordination, cognitive tests, critical flicker fusion, and dynamic visual acuity.
• No detrimental impact on cognitive or psychomotor functions was observed with either cimetidine or ranitidine.

Conclusions:

• Cimetidine (200-400 mg) and ranitidine (150-300 mg) are unlikely to impair performance in healthy individuals.
• These medications can be safely used by individuals engaged in skilled activities.
• The findings support the safety profile of these H2 antagonists concerning cognitive and psychomotor functions.