7 DRUG INTERACTIONS
7.1 Drugs Having Clinically Important Interactions with PRISTIQ
| Monoamine Oxidase Inhibitors (MAOI) | |
| Clinical Impact | The concomitant use of SSRIs and SNRIs including PRISTIQ with MAOIs increases the risk of serotonin syndrome. |
| Intervention | Concomitant use of PRISTIQ is contraindicated:
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| Examples | selegiline, tranylcypromine, isocarboxazid, phenelzine, linezolid, methylene blue |
| Other Serotonergic Drugs | |
| Clinical Impact | Concomitant use of PRISTIQ with other serotonergic drugs increases the risk of serotonin syndrome. |
| Intervention | Monitor for symptoms of serotonin syndrome when PRISTIQ is used concomitantly with other drugs that may affect the serotonergic neurotransmitter systems. If serotonin syndrome occurs, consider discontinuation of PRISTIQ and/or concomitant serotonergic drugs [see Warnings and Precautions (5.2)]. |
| Examples | other SNRIs, SSRIs, triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, buspirone, amphetamines, tryptophan, and St. John's Wort |
| Drugs that Interfere with Hemostasis | |
| Clinical Impact | Concomitant use of PRISTIQ with an antiplatelet or anticoagulant drug may potentiate the risk of bleeding. This may be due to the effect of PRISTIQ on the release of serotonin by platelets. |
| Intervention | Closely monitor for bleeding for patients receiving an antiplatelet or anticoagulant drug when PRISTIQ is initiated or discontinued [see Warnings and Precautions (5.4)]. |
| Examples | NSAIDs, aspirin, and warfarin |
| Drugs that are Primarily Metabolized by CYP2D6 | |
| Clinical Impact | Concomitant use of PRISTIQ increases Cmax and AUC of a drug primarily metabolized by CYP2D6 which may increase the risk of toxicity of the CYP2D6 substrate drug [see Clinical Pharmacology (12.3)]. |
| Intervention | Original dose should be taken when co-administered with PRISTIQ 100 mg or lower. Reduce the dose of these drugs by up to one-half if co-administered with 400 mg of PRISTIQ. |
| Examples | desipramine, atomoxetine, dextromethorphan, metoprolol, nebivolol, perphenazine, tolterodine |
7.2 Drugs Having No Clinically Important Interactions with PRISTIQ
Based on pharmacokinetic studies, no dosage adjustment is required for drugs that are mainly metabolized by CYP3A4 (e.g., midazolam), or for drugs that are metabolized by both CYP2D6 and CYP3A4 (e.g., tamoxifen, aripiprazole), when administered concomitantly with PRISTIQ [see Clinical Pharmacology (12.3)].
7.3 Alcohol
A clinical study has shown that PRISTIQ does not increase the impairment of mental and motor skills caused by ethanol. However, as with all CNS-active drugs, patients should be advised to avoid alcohol consumption while taking PRISTIQ.
7.4 Drug-Laboratory Test Interactions
False-positive urine immunoassay screening tests for phencyclidine (PCP) and amphetamine have been reported in patients taking desvenlafaxine. This is due to lack of specificity of the screening tests. False positive test results may be expected for several days following discontinuation of desvenlafaxine therapy. Confirmatory tests, such as gas chromatography/mass spectrometry, will distinguish desvenlafaxine from PCP and amphetamine.