“If your depression symptoms get worse as soon as you start taking an antidepressant, or they get better and then very suddenly get worse, it's a sign that the depression medication isn't working properly, and you should see your healthcare professional right away,” Hullett says.
If you feel like your antidepressant has stopped working, you're not alone. It's common for a medication that once worked wonders to become ineffective, especially if you've been taking it for a long time. Symptoms return for up to 33% of people using antidepressants — it's called breakthrough depression.
When medication no longer works as well for someone as it did when they first started taking it, that person is said to have developed a tolerance for the drug. The medical term for decreased effectiveness of the medication is tachyphylaxis, although some people refer to it as "Prozac poop-out."
Bottom Line. Within the first one to two weeks, most people feel lower levels of anxiety, restlessness or tiredness with Prozac treatment. Your sleep, energy and appetite may improve over the first month and you may have a better focus on daily tasks. A depressed mood can take up to 8 weeks to fully respond.
Taking Prozac for anxiety is often a successful treatment approach, but it may not be helping your anxiety if the dose is not high enough to control your symptoms. It's also possible that Prozac is not a good fit for your body's chemical makeup—certain people may not respond well to certain SSRIs.
Anxiety and nervousness
In addition to insomnia, anxiety and nervousness are other activating side effects of Prozac. These side effects usually happen early in treatment and then improve with time. But for some people, they can be more intense and cause panic attacks.
The lowdown. Prozac (active ingredient: fluoxetine) is a commonly prescribed SSRI for anxiety. Prozac takes between two and six weeks to take effect and needs to be continued for at least six months to a year. It is generally considered a safe medication for long-term use and is not addictive.
The common occurrence of slow-rolling eye movements during non-rapid eye movement (NREM) sleep in patients taking Fluoxetine has led to this finding being referred to as “Prozac Eyes” [1]. The oculomotor movements in patients on Fluoxetine are accompanied by an increase in myoclonic activity[2].
Your Mood Still Hasn't Improved After Several Months
Generally, people see improvement after taking their antidepressants for three months. If you've been on antidepressants for three months and don't see any improvements in your symptoms or mood, then it's possible your antidepressant dose is too low.
Long-term side effects
Sexual side effects, such as problems getting an erection or a lower sex drive, have been reported after taking fluoxetine for a long time. In some cases, these can continue even after stopping the medicine.
The “blunting of emotions” is frequently mentioned by patients taking SSRIs for long periods who report that, although they feel less emotional pain than before, they also experience a restricted range of other emotions that are a normal part of everyday life (Barnhart et al.
The antidepressant Prozac and related drugs are no better than … placebo in treating all but the most severely depressed patients, according to a damaging assessment of the latest generation of antidepressants.
It may be hard to believe that antidepressants can cause depression, but it could be true. The very reason you take depression medication can sometimes make symptoms worse. Depression is a mood disorder that can cause feelings of sadness and lack of energy, among other symptoms.
However, studies have shown that a small number of people (especially people younger than 25) who take antidepressants for any condition may experience worsening depression, other mental/mood symptoms, or suicidal thoughts/attempts.
SSRIs release two chemicals in the brain that kick in at different times, causing a period of negative effects on mental health, the authors report. The first chemical is serotonin, which is released very soon after an SSRI is taken but might not lessen depressive symptoms until after a couple of weeks.
You can feel drowsy in the first few days of taking fluoxetine. However, it should get better after the first week or two. You may become more anxious, or it may make you irritable. This should settle after a couple of weeks.
Systemic bioavailability — In man, following a single oral 40-mg dose, peak plasma concentrations of fluoxetine from 15 to 55 ng/mL are observed after 6 to 8 hours.
What is the peak time for Prozac? Peak plasma concentration of Prozac occurs 6-8 hours after taking the drug. It works best when taken every day for 2-4 weeks. Prozac has a long half-life of 2-4 days, meaning that it takes that long for the dose in your body to be reduced by half.
The usual dose of fluoxetine for adults is 20mg a day. However, you may start at a lower dose and gradually be increased to a maximum dose of 60mg a day. Some people might need to take a lower dose of fluoxetine. This includes people with liver problems, and older people.
Prozac works for anxiety largely by helping manage symptoms. It's a daily maintenance medication, and Prozac is not designed to be highly effective at stopping a panic attack that's in progress. As an SSRI, Prozac helps anxiety by keeping serotonin in your system, helping your mood, energy levels, and more.
If you experience a positive response to Prozac, you might notice a decrease in your anxiety symptoms and feel more like yourself again. You may: Feel more relaxed and less anxious. See improved sleep and appetite.
The main ocular side effects of SSRIs are dry eye and a possible risk of the development of cataract.
Which is More Effective? Both Prozac and Zoloft are considered powerful mental health medications, comparably effective at treating depression and reducing anxiety for the patients who take them. A few clinical trials suggest that Zoloft may have less serious side effects than Prozac.
Other medications that help in controlling intrusive thoughts are: Paroxetine (Pexeva)—prescribed only for adults. Fluoxetine (Prozac)—for children above seven years and also for adults. Sertraline (Zoloft)—for children above six years and for adults.
Do not use fluoxetine with buspirone (Buspar®), fentanyl (Abstral®, Duragesic®), lithium (Eskalith®, Lithobid®), tryptophan, St. John's wort, amphetamines, or some pain or migraine medicines (eg, rizatriptan, sumatriptan, tramadol, Frova®, Imitrex®, Maxalt®, Relpax®, Ultram®, Zomig®).