Half-life helps explain dosing frequency and how long a drug's effects and interaction risks may linger after a dose. Because trazodone's half-life is measured in hours rather than days, its sedating effects are typically most noticeable within the first several hours after a dose — which is part of why it is usually taken at bedtime when prescribed for sleep.
Half-life
Also called: Elimination half-life
The time it takes for the amount of a drug in the body to fall by half. For trazodone, published estimates generally fall in the range of about 5 to 9 hours in adults, though individual results vary.