Final answer:
Venlafaxine and duloxetine are SNRIs contraindicated with MAOIs due to the risk of serotonin syndrome, and with other substances that could lead to serious interactions. They should also be avoided in cases of uncontrolled narrow-angle glaucoma and by individuals with allergies to the drugs or their components.
Step-by-step explanation:
Venlafaxine and duloxetine are antidepressant medications classified as serotonin-norepinephrine reuptake inhibitors (SNRIs). These medications are primarily used for the treatment of major depressive disorder, anxiety disorders, and other conditions. They are contraindicated with certain drugs and substances due to the risk of serious interactions.
Both venlafaxine and duloxetine are contraindicated with monoamine oxidase inhibitors (MAOIs), which are another class of antidepressants. The combination of SNRIs with MAOIs can lead to a life-threatening condition called serotonin syndrome, which is caused by an excess of serotonin in the brain. Symptoms of serotonin syndrome may include agitation, hallucinations, coma, rapid heart rate, temperature fluctuations, and overactive reflexes.
They are also contraindicated in individuals who are allergic to these drugs or their ingredients, as well as in situations when there is uncontrolled narrow-angle glaucoma. Both drugs should be used cautiously with other medications that can increase serotonin levels, such as triptans used for migraines, other antidepressants, or herbal supplements like St. John's Wort.
Other contraindications include the use of these medications together with blood thinners, as they can increase the risk of bleeding. Patients should always consult their healthcare provider before starting, stopping, or combining these medications with others. It is critical to be aware of potential drug interactions and contraindications to prevent adverse reactions.