The manufacturers warn that Prozac should not be taken together with:
- monoamine oxidase inhibitors (MAOIs): Pimozide and Thioridazine
- drugs metabolized by CYP2D6
- tricyclic antidepressants (TCAs)
Care should be taken when used with drugs that affect the central nervous system (CNS), such as those belonging to the “benzodiazepines” class of drugs. Examples include Diazepam and Lorazepam.
It should be used with care with non-steroidal anti-inflammatories (NSAIDs), aspirin, warfarin and other drugs that affect blood coagulation, as there is a risk that it could lead to bleeding.
Prozac should not be used with antipsychotics, other SSRIs and other serotonergic agents, including lithium and St. John’s Wort.
There is also a chance that fluoxetine may activate mania in a person who is susceptible.
Prozac is selective serotonin reuptake inhibitor (SSRI). It works by blocking the absorption of the neurotransmitter serotonin in the brain.
Regulating the amount of serotonin helps brain cells transmit messages to each other. This results in a better and more stable mood. It also results in more neurons being present in a region of the brain called the “dentate gyrus,” part of the hippocampal formation. The hippocampus plays a role in forming memories.
The U.S. Food and Drug Administration (FDA) currently approves Prozac for acute and maintenance treatment of major depressive disorder (MDD), obsessive compulsive disorder (OCD), bulimia nervosa, and panic disorder, with or without agoraphobia.
Prozac is normally used alone. However, fluoxetine combined with olanzapine (OFC) can also be used to treat depressive episodes in people with bipolar disorder. Fluoxetine combined with olanzapine is known as Symbyax. This combination can also help people with treatment-resistant depression.
Some doctors may prescribe Prozac “off-label” to treat anxiety, premature ejaculation, obesity, and binge-eating disorder.
Prozac can be used to treat depression in adults. It can also be used for children and adolescents from the age of 10 to 19 years with severe, persistent depression. However, the National Institute of Mental Health (NIMH) urge caution, as a small subset of adolescents have shown suicidal tendencies after using it.
A review comparing the effectiveness of Prozac with other antidepressants found that it appears to be similarly effective, and possibly better tolerated. However, the authors concluded that more research is needed, as a number of factors made an exact comparison difficult.
Findings reported in Progress in Neuro-Psychopharmacology and Biological Psychiatry have suggested that some patients’ depression does not respond to treatment with the SSRIs paroxetine (Paxil) and citalopram (Celexa), because of a specific genetic factor. These patients, say the researchers, may benefit from a switch to Prozac.
A number of studies have suggested that Prozac can reduce the incidence of panic attacks in people with panic disorder.
In one study, around 7 percent of patients reported experiencing increased anxiety in the first few weeks after they started using Prozac, compared with 9 percent who took a placebo. However, compared with the overall benefits, this is considered small enough that Prozac is still “safe and effective” as a treatment for anxiety and panic attacks.
Obsessive-compulsive disorder (OCD)
SSRIs normally need to be taken for at least 11 weeks before a person with OCD experiences any benefits. Patients with OCD normally use an SSRI such as Prozac for at least a year, depending on the individual’s needs and situation.
A study published in the Journal of the American Academy of Child and Adolescent Psychiatry, concluded that a 20 to 60 milligram (mg) dose of fluoxetine was effective in treating children and adolescents with OCD. Participants also tolerated the drug well.
Researchers reported in The American Journal of Psychiatry that for patients with bulimia nervosa who had not responded to psychological treatment, fluoxetine may be a useful intervention. It may provide benefits for bulimia if it is taken for up to a year.