Citalopram is used for the treatment of depression, as indicated by the FDA label. Off-label indications include but are not limited to: treatment of sexual dysfunction, post-stroke behavioural changes, ethanol abuse, obsessive-compulsive disorder (OCD) in children, and diabetic neuropathy.
Citalopram belongs to a class of antidepressant agents known as selective serotonin-reuptake inhibitors (SSRIs) and is widely used to treat the symptoms of depression. Its chemical structure is unrelated to that of other SSRIs or of tricyclic, tetracyclic, or other prescribed antidepressants.
Citalopram is also known as Celexa, and available in tablet and solution forms. This drug was initially approved by the FDA in 1998.
Citalopram belongs to a class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs). It has been found to relieve or manage symptoms of depression, anxiety, eating disorders and obsessive-compulsive disorder among other mood disorders.
The antidepressant, anti-anxiety, and other actions of citalopram are linked to its inhibition of CNS central uptake of serotonin. Serotonergic abnormalities have been reported in patients with mood disorders. Behavioral and neuropsychological of effects of serotonin include the regulation of mood, perception, reward, anger, aggression, appetite, memory, sexuality, and attention, as examples. The onset of action for depression is approximately 1 to 4 weeks. The complete response may take 8-12 weeks after initiation of citalopram.
In vitro studies demonstrate that citalopram is a strong and selective inhibitor of neuronal serotonin reuptake and has weak effects on norepinephrine and dopamine central reuptake.
The chronic administration of citalopram has been shown to downregulate central norepinephrine receptors, similar to other drugs effective in the treatment of major depressive disorder. Citalopram does not inhibit monoamine oxidase
The mechanism of action of citalopram results from its inhibition of CNS neuronal reuptake of serotonin (5-HT). The molecular target for citalopram is the serotonin transporter (solute carrier family 6 member 4, SLC6A4), inhibiting its serotonin reuptake in the synaptic cleft.
Citalopram binds with significantly less affinity to histamine, acetylchline, and norepinephrine receptors than tricyclic antidepressant drugs.
This drug has no or neglible affinity for 5-HT1A, 5-HT2A, dopamine D1 and D2, α1-, α2-, and_ β adrenergic, _histamine H1, gamma-aminobutyric acid (GABA), muscarinic, cholinergic, and benzodiazepine receptors. Antagonism of muscarinic, histaminergic, and adrenergic receptors is thought to be associated with several anticholinergic, sedative, and cardiovascular effects of other psychotropic drugs.
Metabolism: Citalopram is metabolized mainly in the liver via N-demethylation to its main metabolite, demethylcitalopram by CYP2C19 and CYP3A4. Other metabolites include didemethylcitalopram via CYP2D6 metabolism, and citalopram N-oxide via monoamine oxidase enzymes and aldehyde oxidase. It is a deaminated propionic acid derivative.
After a single dose of citalopram, peak blood concentrations occur at approximately 4 hours. This drug in is found mainly unchanged in the plasma as citalopram. Cytochrome P450 (CYP) 3A4 and 2C19 isozymes appear to be heavily involved in producing demethylcitalopram. Demethylcitalopram appears to be further N-demethylated by CYP2D6 to didemethylcitalopram. Citalopram metabolites exert little pharmacologic activity in comparison to the parent drug and are not likely to contribute to the clinical effect of citalopram.
Absorption: Rapidly and well absorbed from the GI tract. Peak plasma concentrations occur within 4 hours of a single orally administered dose. Bioavailability is 80% following oral administration. Food does not affect absorption.
Route of elimination: 12-23% of an oral dose of citalopram is found unchanged in the urine, while 10% of the dose is found in the faeces.
Half life: About 35 hours
All medicines may cause side effects, but many people have no, or minor, side effects.Some medical conditions may interact with Citalopram.
Tell your doctor or pharmacist if you have any medical conditions.
Common citalopram side effects may include: problems with memory or concentration, headache, drowsiness, dry mouth, increased sweating, numbness or tingling, increased appetite, nausea, diarrhea, gas, fast heartbeats, feeling shaky, sleep problems (insomnia), feeling tired, cold symptoms such as stuffy nose, sneezing, sore throat, changes in weight or difficulty having an orgasm.
Taking an SSRI antidepressant during pregnancy may cause serious lung problems or other complications in the baby. However, you may have a relapse of depression if you stop taking your antidepressant. Tell your doctor right away if you become pregnant. Do not start or stop taking this medicine during pregnancy without your doctor's advice.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.
