Drug interactions
Dapagliflozin-metformin + Promethazine
Severity: Minor
Dapagliflozin-metformin and Promethazine: minor interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Promethazine, a phenothiazine, can raise blood glucose in some patients and may weaken the glucose-lowering effect of metformin. The effect is usually modest, but glycaemic control may drift when promethazine is started, and hypoglycaemia is possible if it is later stopped.
What this interaction means in plain words
Dapagliflozin-metformin and Promethazine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Dapagliflozin-metformin belongs to Endocrine; Promethazine belongs to Respiratory.
Why it happens
Phenothiazines may cause hyperglycaemia through reduced insulin sensitivity or secretion, opposing the antidiabetic effect (pharmacodynamic antagonism).
What to do
Check blood glucose more often when promethazine is started or stopped, especially with repeated or long-term use. Adjust the antidiabetic regimen if glucose control changes.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Dapagliflozin-metformin
Other interactions of Promethazine
- Ibutilide + Promethazine Contraindicated
- Pimozide + Promethazine Contraindicated
- Promethazine + Thioridazine Contraindicated
- Alfentanil + Promethazine Major
- Amiodarone + Promethazine Major
- Amisulpride + Promethazine Major
Frequently asked questions
Can I take Dapagliflozin-metformin with Promethazine?
MediHelp rates the interaction as minor. Dapagliflozin-metformin and Promethazine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Promethazine, a phenothiazine, can raise blood glucose in some patients and may weaken the glucose-lowering effect of metformin. The effect is usually modest, but glycaemic control may drift when promethazine is started, and hypoglycaemia is possible if it is later stopped.
How serious is the interaction between Dapagliflozin-metformin and Promethazine?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check blood glucose more often when promethazine is started or stopped, especially with repeated or long-term use. Adjust the antidiabetic regimen if glucose control changes.
What other medicines interact with Dapagliflozin-metformin?
MediHelp also lists interactions of Dapagliflozin-metformin with, for example, Contrast media, Diatrizoate, Diatrizoate meglumine / diatrizoate. The full list is on the Dapagliflozin-metformin page.
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