Each week we will aim to bring out a concise email that provides 4-5 key pieces of information addressing a specific issue in clinical therapeutics. This week:
SSRI drug interactions (part two)
Following on from our last edition, this week we further explore other interactions involving the very widely prescribed SSRI antidepressants. The SSRIs are also associated with a range of significant pharmacodynamics drug interactions.
- The coadministration of SSRIs with other antidepressants drugs is generally not regarded as good practice, and creates a significant risk for serotonin toxicity. This is a serious clinical syndrome associated with a range of signs and symptoms including agitation, confusion, tachycardia, myoclonus, diaphoresis, diarrhoea, rigours and high fever. More severe manifestations includes seizures, arrhythmias and impaired conscious. If unrecognized or untreated, serotonin toxicity can be lethal
- SSRIs can impair platelet aggregation, and may contribute to major bleeding. The risk is especially high if SSRIs are coadministered with other drugs that can inhibit platelet aggregation, such as aspirin, NSAID agents such as diclofenac, naproxen or celecoxib. The risk may also be compounded by the use of other drugs such as warfarin, dabigatran, rivaroxaban, apixaban or clopidogrel. The major risk is gastrointestinal bleeding, but other risks include intracranial haemorrhage and increased post-operative bleeding.
- The increased risk of GI bleeding associated with the combinations referred to above may be reduced by the addition of a Proton Pump Inhibitor (PPI) such as omeprazole, pantoprazole or esomeprazole, but some PPIs should not be coprescribed with clopidogrel.
- Certain drugs may compound side effects associated with SSRIs – additive effects such as nausea and vomiting, tremor, and increased sweating may be observed when SSRIs are co-prescribed with other drugs that also share these adverse effects.
Please consider these issues when preparing RMMR reports or education sessions. Contributions of content or suggested topics are welcome and should be sent directly to firstname.lastname@example.org