In Germany alone, several million people suffer from depression. The antidepressant fluoxetine promises them help: by increasing the serotonin content in the brain, fluoxetine provides an artificial high and gives those affected new drive. In addition to treating depression, the antidepressant is also used to treat obsessive-compulsive disorder and bulimia. Taking fluoxetine can cause side effects such as vomiting and nausea.
Side effects of fluoxetine
Because fluoxetine has little effect on receptors in the brain and nervous system, unlike other antidepressants such as the tricyclic antidepressants, fluoxetine also has fewer side effects. Similar to the other selective serotonin reuptake inhibitors (SSRIs), nausea and vomiting are among the very common side effects of fluoxetine. Fatigue, nervousness, headache, dizziness, or impaired thinking are common after taking it. Muscle and joint pain, drop in blood pressure, or itching also occur occasionally. Furthermore, fluoxetine may also have effects on weight: Weight gain is possible, but some patients also report weight loss. Recent studies also suggest that taking fluoxetine may lead to an increased risk of osteoporosis.
On the effects of fluoxetine
The active ingredient fluoxetine belongs to the group of SSRIs (selective serotonin reuptake inhibitors). SSRIs ensure that the concentration of serotonin in the brain is increased. This is because, according to current research findings, a deficiency of the neurotransmitters norepinephrine and serotonin in the brain is considered to be the cause of depression. A higher serotonin content in the brain has a mood-lifting and activating effect on those affected. In its effect, fluoxetine thus differs significantly from other antidepressants such as mirtazapine, which has a more depressant effect. Fluoxetine increases the concentration of serotonin in the brain by inhibiting the transport substances that bring serotonin back to its storage sites. Thus, the reuptake of serotonin is slowed and the neurotransmitter can remain longer in the synaptic cleft. The dosage of fluoxetine should be discussed with a physician in each case and individually tailored to the patient.
Increased risk of suicide in the first few weeks
Characteristic of the effect of fluoxetine is that it not only has a mood-lifting effect on the patient, but also an activating effect. The activating effect sets in promptly after ingestion, but the antidepressant effect does not fully develop until about two to three weeks later. As a result, taking fluoxetine, as well as other active ingredients of the SSRI class such as citalopram, fluvoxamine, paroxetine and sertraline, carries a further risk: especially in the first few weeks, there is a warning of an increased risk of suicide. Young adults are considered to be at particularly high risk. Experts recommend that patients control their moods and feelings themselves, but also be closely monitored by the attending physician and relatives or acquaintances.
Interactions
When fluoxetine and a monoamine oxidase (MAO) inhibitor are taken at the same time, severe physical reactions such as serotonin syndrome may occur. In this poisoning, seizures, nausea, diarrhea, and confusion occur due to severely elevated serotonin levels that are difficult to control. In a severe course, serotonin syndrome can be life-threatening. Because of the long half-life of fluoxetine, which is 4 to 16 days, wait at least five weeks after discontinuation before switching to MAO inhibitors. Interactions may also occur when taking phenytoin, lithium salts, L-tryptophan, and drugs with serotonergic effects (e.g., tramadol, triptans). In patients with impaired liver function, diabetes, or acute heart disease, fluoxetine use must be monitored and discontinued if problems occur. Interactions may also occur when taking herbal medicines, such as St. John’s wort.
Further notes
- Fluoxetine must not be taken in case of allergy or hypersensitivity to the active substance.
- During treatment with the antidepressant should be avoided alcohol, otherwise the alcohol effect may be enhanced.
- Taking fluoxetine may adversely affect reaction time and driving ability.
- For children and adolescents under 18 years, the antidepressant fluoxetine is generally not suitable.
- Likewise, pregnant as well as breastfeeding women are also advised against taking it. Caution is especially advised in the last months of pregnancy, as fluoxetine may also have effects on the newborn. These include tremors, low muscle tone, and problems with sucking and sleeping.
- Headache, nausea, dizziness, and anxiety may occur after discontinuation of fluoxetine.
