Prozac for Anxiety Disorders

Side Effects, Interactions and Risks

Woman with hair blowing looking out window of car
Thomas Barwick/Getty Images

Prozac is an antidepressant that was first introduced in the United States to treat depression in the 1980s. It is part of a class of medications known as selective serotonin reuptake inhibitors (SSRIs). Prozac is mainly used to treat major depression, obsessive-compulsive disorder, and panic disorder (approved uses by the U.S. Food and Drug Administration) but is also sometimes used off-label to treat other anxiety disorders.

How Prozac Helps With Anxiety

Mechanism of Action

As an SSRI, Prozac works by preventing the brain from reabsorbing naturally occurring serotonin. Serotonin is involved in mood regulation. In this way, Prozac helps the brain to maintain enough serotonin so that you have a feeling of well-being, resulting from improved communication between brain cells.

Research also highlights how medications such as Prozac may help in combination with psychotherapy. In a 2008 study published in Science, it was shown that in mice, Prozac helped the brain to enter a more immature and plastic state, possibly making it easier for therapy to have an effect. We do know that combining medication such as Prozac with talk therapy is effective for anxiety, and this study indicates a potential reason why.

What It Feels Like to Take Prozac

If you experience a positive response to Prozac, you might notice a decrease in your anxiety symptoms. Depending on your specific symptoms, you might feel more relaxed and less anxious, improvements in sleep and appetite, interest in life, increased energy, improved ability to focus, and feeling more like yourself again. 

Remember that it may take time for these improvements to become noticeable—even up to 12 weeks in some cases. You may also experience side effects at first, so it may be hard to notice the improvements until the side effects lessen.

Using Prozac for Anxiety

Obtaining a Prescription

Prozac is often considered a first-line treatment for anxiety disorders. However, there are a number of steps involved in obtaining a prescription. Generally, a diagnosis of a mental health disorder must be given before you would be prescribed Prozac. While a family doctor is capable of writing a prescription, the process is better handled by a mental health professional who can prescribe medication, such as a psychiatrist.

Dosage and Administration

Prozac is usually prescribed at a low dose to start, and then gradually increased to 20 mg per day. The maximum dose is 80 mg a day. It is taken as a liquid or capsule, and should be used as prescribed. It can take several weeks for effects to show, so it is important not to stop taking Prozac abruptly if you think it is not working. Only take the medication as prescribed by your doctor or psychiatrist. Stopping cold turkey could be dangerous and cause withdrawal symptoms.

Safety of Prozac

There has been some controversy as to the safety of Prozac, due to the issuing of a safety warning by the U.S. Food and Drug Administration in 2007 about the risk for suicidal thoughts among certain groups. Despite this warning, Prozac continues to be prescribed and can be used safely (or discontinued if adverse effects develop) when under the guidance of a physician. If you have concerns about the safety of taking Prozac, bring these up to your doctor.

Medication Interactions

Prozac should not be combined with monoamine oxidase inhibitors (MAOIs) or taken within 14 days of discontinuing an MAOI. Allow at least 5 weeks after stopping Prozac before starting an MAOI. Use of pimozide and thioridazine also increases the risk involved in taking Prozac. The result of medication interactions can be serious and potentially fatal, so you should discuss all medications you are taking with your doctor or psychiatrist to determine whether potential interactions exist.

Side Effects 

Some side effects of Prozac are more likely than others. Some common side effects include sleep problems, headaches, fatigue, dizziness, nausea, loss of appetite, anxiety, lightheadedness, yawning, sweating, sexual problems, dry mouth, heart burn, diarrhea, and blurred vision. Some people notice that side effects lessen over time, or become less bothersome.

Other potential side effects that are rare include vomiting, seizures, rash/hives, fever, swelling, feeling confused, extreme anxiety, trouble breathing or swallowing, bleeding or bruising, and suicidal thoughts or behavior. If you experience any of these, be sure to notify your doctor or psychiatrist.

Who Should Not Take Prozac

Prozac can be passed to babies during pregnancy and through breast milk. Consult with your doctor if you are pregnant or nursing before taking Prozac, to determine whether the benefits outweigh the risks.

There are also some potential risks for individuals age 65 or older that should be discussed with your doctor. The safety and effectiveness of Prozac for use with children younger than 18 years of age has also not been established. 

Drug Interactions

Prozac should not be combined with alcohol, certain over-the-counter (e.g., aspirin, due to risk of bleeding) and prescription medications, and nutritional supplements or herbs (e.g., St. John's Wort). Be sure to tell your doctor about everything that you are taking.

Prozac should not be taken at the same time as monoamine oxidase inhibitors (MAOIs) (pimozide and thioridazine), tricyclic antidepressants (TCAs), or drugs metabolized by CYP2D6.

Care should also be taken if using alongside drugs that affect the central nervous system (CNS), such as benzodiazepines.

Warnings

Use of Prozac can carry risks, including the potential for clinical worsening and in rare cases, increased thoughts of suicide. Serotonin syndrome can also occur, particularly if used in conjunction with certain other medications. Close monitoring by your psychiatrist or doctor is important.

Prozac also comes with a Black box warning that it may increase the risk of suicide in people younger than 25 years old. In these individuals, it may lead to suicidal thoughts, or worsening of these types of thoughts. If you belong to this group, your doctor should monitor you, particularly in the early stages, for these serious issues.

Prozac may also activate mania in people who are prone.

Withdrawal

Prozac should always be tapered off to avoid withdrawal effects. If you stop taking Prozac all of a sudden, you may notice symptoms such as dizziness, confusion, nightmares, insomnia, irritability, crying spells. For this reason, never stop a medication without consulting your doctor.

Other Options

If Prozac is not well tolerated, other SSRIs that are sometimes prescribed for anxiety include  Paxil (paroxetine), Lexapro (escitalopram), Luvox CR (fluvoxamine) and Zoloft (sertraline). Effexor XR (venlafaxine) is another antidepressant called a serotonin-norepinephrine reuptake inhibitor (SNRI) that also may be effective in treating your anxiety.

Finally, benzodiazepines are another class of medication often used for anxiety, but they are generally a short-term solution because of their risk for dependence. Typical medications in this category include  Valium (diazepam), Xanax (alprazolam),  Klonopin (clonazepam) and Ativan (lorazepam).

A Word From Verywell

If you've been prescribed Prozac for anxiety, you may feel worried about side effects and whether the medication will be helpful. Share your concerns with your doctor and stay in contact about how you are doing once you begin the medication. Communication is key to ensuring that this medication is used in an appropriate way for maximum effectiveness.

Was this page helpful?
View Article Sources
  • Eli Lilly. Prozac Medication Guide
  • Eli Lilly. Prozac Prescribing Information
  • Maya Vetencourt JF, Sale A, Viegi A, et al. The antidepressant fluoxetine restores plasticity in the adult visual cortex. Science. 2008;320(5874):385-388. 
  • Medline Plus. Fluoxetine. The American Society of Health-System Pharmacists, Inc. U.S. National Library of Medicine.