Dosisinterval

Dosisinterval, or dosing interval, is the time between successive doses of a medicine. It is a central parameter in pharmacotherapy that helps maintain drug concentrations within a therapeutic range throughout treatment, balancing efficacy with safety.

The interval is influenced by pharmacokinetics and pharmacodynamics. Key factors include the drug’s half-life, frequency of absorption and distribution, the duration of the drug’s effect, and the therapeutic window. Formulation and route of administration (oral, intravenous, etc.) also matter, as do patient-specific factors such as age, kidney and liver function, pregnancy status, body weight, and potential drug interactions.

In practice, the dosing interval is chosen to maintain effective drug exposure without causing accumulation that could lead to toxicity. Drugs with short half-lives often require shorter intervals or continuous infusion, while long-acting drugs may be given less frequently. For drugs with a narrow therapeutic index, trough levels are monitored and the interval may be adjusted to keep concentrations within a safe range.

Common considerations include loading doses to rapidly reach therapeutic levels, followed by maintenance intervals that sustain those levels. In renal or hepatic impairment, dosing intervals may be extended. Pediatric dosing frequently uses weight-based intervals, and extended-release formulations may shorten the needed dosing frequency by prolonging action.

Related topics include pharmacokinetics, half-life, and therapeutic window.