Interaction between Valproic acid and Imipenem
Major
Others
| ID | DDInter1913 and DDInter911 |
| Interaction | Coadministration with carbapenem antibiotics may substantially decrease the serum concentrations of valproic acid (VPA) and increase the risk of breakthrough seizures. The exact mechanism of interaction is unknown. |
| Management | Concomitant use of valproic acid with carbapenem antibiotics is generally not recommended. Use of alternative antibiotics should be considered in patients whose seizures are well controlled on valproic acid therapy. If coadministration is required, supplemental anticonvulsant therapy may be advisable, since increasing the valproic acid dose alone may not be sufficient to overcome the interaction. Nevertheless, pharmacologic response and serum valproate levels should be monitored closely following the addition or withdrawal of carbapenem treatment, and the dosage adjusted as necessary. |
| References | |
| Alternative for Valproic acid |
N03A
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| Alternative for Imipenem |
J01D
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Potential Metabolism Interactions
Substrate-Substrate Interaction：If more than one drug is metabolized by the same CYP, it is possible that its metabolism is inhibited because of the competition between the drugs. That means, it can be useful to lower the dosage of the drugs in the drug-cocktail because they remain longer in the organism than in monotherapy.
Inhibitor-Inhibitor Interaction：Combining two or more inhibitors of one CYP, should be compensated by lowering the dosage of these drugs because the metabolism is reduced and the drugs remain longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.
Inhibitor-Substrate Interaction：Combining drugs that have inhibitory effect and are substrates of one particular CYP, should be compensated by lowering the dosage. They rest longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.