It takes about one to two weeks for paroxetine to kick in and start working, but sometimes can take a few months to reach its fullest effect. Sometimes, healthcare providers will start you on a lower dose and work the dosages up until they are fully effective over time.
When taking an antidepressant like paroxetine, it is important to have regular check-ins with your healthcare to ensure that paroxetine is the right antidepressant for you. If you are having bothersome side effects or are not feeling any improvement in your condition, you should discuss if paroxetine is right with your healthcare provider. Do not try to determine on your own if paroxetine is working and do not stop taking your medication without consulting your healthcare provider.
Paroxetine can cause you to feel sleepy because, in addition to mood, serotonin is an important neurotransmitter for regulating sleep and appetite. Paroxetine’s effect on serotonin may result in sleepiness or other changes in sleep. If you feel severe fatigue, consult your healthcare provider.
In some cases, paroxetine may cause weight gain in both long-term and short-term use.
Rare but serious adverse effects of paroxetine include worsening depression, suicidal thoughts or suicide, mania, seizures, risk of serotonin syndrome, toxic epidermal necrolysis (extreme blistering or peeling of the skin), hyponatremia (a condition that occurs when levels of sodium are too low in the blood), abnormal bleeding, acute hepatitis, and Stevens-Johnson syndrome.
Interactions with paroxetine include MAOIs (monoamine oxidase inhibitors such as methylene blue injection), pimozide, thioridazine, buspirone, lithium, tryptophan, St. John’s wort, amphetamines, warfarin, fluoxetine, tamoxifen, sertraline, citalopram, duloxetine, atomoxetine, diuretics, certain NSAIDs (such as ibuprofen), and more. This list is non-exhaustive.
Talk to a healthcare professional about any current medications before you use paroxetine.