Drug Interaction Probability Scale (DIPS)
Drug Interaction Probability Scale (Horn 2007) for one suspected interaction.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Previous credible reports of this interaction in humans
- Yes
- Consistent with known properties of the precipitant drug
- Yes
- Consistent with known properties of the object drug
- Yes
- Consistent with the known or reasonable time course
- Yes
- Remitted on stopping the precipitant, object drug unchanged
- unknown
- Reasonable alternative causes for the event
- No
- Object drug levels consistent with the interaction
- No
- Other objective evidence of the effect on the object drug
- No
- Greater with a higher precipitant dose, or less with a lower one
- Yes
Result: DIPS score 6: probable drug interaction.
The tool opens with these values already filled in. Replace them with your own.
What you enter
- Previous credible reports of this interaction in humans
- Consistent with known properties of the precipitant drug
- Consistent with known properties of the object drug
- Consistent with the known or reasonable time course
- Remitted on stopping the precipitant, object drug unchanged
- Reappeared on restarting the precipitant
- Reasonable alternative causes for the event
- Object drug levels consistent with the interaction
- Other objective evidence of the effect on the object drug
- Greater with a higher precipitant dose, or less with a lower one
How this is calculated
Citation
Horn JR, Hansten PD, Chan LN. Ann Pharmacother. 2007;41:674-680. Points and bands as printed in McGrane IR et al. Ment Health Clin. 2021;11:297 and van Dijk LMM et al. Neuropediatrics. 2024;55:294 (open). Read the sources: McGrane 2021 (reprint) ↗, van Dijk 2024 (reprint) ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.