Celexa uses:
Citalopram (Celexa) is in a class of drugs called selective serotonin reuptake inhibitors. This medication is used to treat depression. It works by helping to restore the balance of certain natural chemicals in the brain. This medication has also been used to treat certain eating disorders (e.g., anorexia nervosa, bulimia), social anxiety disorder, premenstrual dysphoric disorder, alcohol dependence, irritable bowel syndrome.

Celexa dosage:

Initial treatment: initiate with 20 mg once daily and titrate up to 40 mg/day; max, 60 mg/day. Dose increases should usually occur in increments of 20 mg at intervals of no less than one week. Doses above 40 mg are not ordinarily recommended. Citalopram should be administered once daily, in the morning or evening, with or without food.
Elderly: initiate with 20 mg once daily and titrate up to 40mg/day if needed.
Hepatic impairment: initiate with 20 mg once daily and titrate up to 40 mg/day if needed.
Maintenance: Periodically reevaluate long-term usefulness if used for extended periods.
If adverse reactions are bothersome, a decrease in dose to 20 mg/day can be considered.

Do not stop taking Citalopram without talking to your doctor. You may suffer withdrawal symptoms if you stop taking antidepressant suddenly.

Dosage for unlabeled uses:

Panic disorder: the most effective dosage for panic disorder is 20 to 30 mg per day. [2, 3]

Irritable Bowel Syndrome (IBS): 20-40 mg per day [4]

Discontinuation of treatment with Citalopram:
Symptoms associated with discontinuation of citalopram have been reported. A gradual reduction in the dose rather than abrupt cessation is recommended whenever possible. If intolerable symptoms occur following a decrease in the dose or upon discontinuation of treatment, then resuming the previously prescribed dose may be considered. Subsequently, the physician may continue decreasing the dose but at a more gradual rate.

Celexa side effects:

Autonomic Nervous System Disorders: dry mouth, sweating iIncreased.
Central & Peripheral Nervous System Disorders: somnolence, insomnia, anxiety, anorexia, tremor, agitation, dysmenorrhea, libido decreased, yawning, aggravated depression, amnesia, apathy, confusion, increased appetite, impaired concentration.
Gastrointestinal Disorders: nausea, diarrhea, dyspepsia, vomiting, abdominal pain, flatulence, increased saliva.
General: fatigue, fever
Musculoskeletal System Disorders: arthralgia, myalgia.
Respiratory System Disorders: upper respiratory tract infection, rhinitis, sinusitis, coughing.
Urogenital: ejaculation disorder, impotence, amenorrhea, polyuria.
Cardiovascular: hypotension, postural hypotension, tachycardia.

There are case reports of citalopram-induced bruxism [5].

Celexa precautions:

Children: Safety and efficacy not established.
Renal Function: Use with caution in patients with severe renal impairment.
Hepatic Function: Use with caution; lower max dose is recommended.
Hazardous Tasks: May impair judgment, thinking, or motor skills.
Seizures: May occur; use with caution in patients with a history of seizures or with conditions that potentially lower the seizure threshold.

Drug interations:

Although Citalopram has relatively low potential to interact with other medicines, do not start new prescription and over-the-counter medication without informing your doctor.

Beta Blockers (ie, carvedilol, metoprolol, propranolol) - inhibition of metabolism of the beta blocker may occur, resulting in excessive beta blockade (eg, bradycardia). Coadministration of metoprolol with citalopram has increased plasma levels of metoprolol 2-fold.
Cimetidine - serum levels of citalopram may be increased 40%.
CNS drugs - use citalopram with caution in patient receiving CNS drugs.
Cyproheptadine - may decrease the pharmacologic effect of citalopram.
Ketoconazole - ketoconazole plasma levels may be reduced slightly.
Lithium - lithium may enhance the serotonergic effects of citalopram; use caution if coadministered.
MAO inhibitors, pimozide - concomitant use with citalopram is contraindicated.
Sumatriptan - rare postmarketing reports of weakness, hyperreflexia, and incoordination following coadministration.

Pregnancy & Lactation:
Citalopram is pregnancy category C.

When citalopram was administered to animals in doses greater than human therapeutic doses there were adverse effects on embryo/fetal and postnatal development, including teratogenic effects. There are no controlled studies in pregnant women.

Citalopram is excreted in human breast milk. The decision to continue citalopram during pregnancy and/or during nursing should be based on the potential benefits to the mother versus the potential risks to the fetus or baby.

Overdose:
If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include: tiredness, weakness, sedation, irregular heartbeat, fainting, severe dizziness or lightheadedness.

Missed dose:
If you miss a dose, use it as soon as you remember. However, if it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not take a double dose of this medication.

Storage:
Store tablets and oral solution at controlled room temperature (59° to 86°F).

Purchasing & Prices:
If you would like to purchase Citalopram (Celexa) with no prescription, choose the offer from the above price table. Other antidepressants from SSRI classs are also available.

References:

1. U.S. Food and Drug Administration. U.S. Prescribing Information. Available at (PDF format): Prescribing Information
2. Wade AG, Lepola U, Koponen HJ, Pedersen V, Pedersen T. The effect of citalopram in panic disorder. Br J Psychiatry. 1997 Jun;170:549-53.
3. Leinonen E, Lepola U, Koponen H, Turtonen J, Wade A, Lehto H. Citalopram controls phobic symptoms in patients with panic disorder: randomized controlled trial. J Psychiatry Neurosci. 2000 Jan;25(1):24-32. PubMedCentral
4. Masand PS, Gupta S, Schwartz TL, Virk S, Hameed A, Kaplan DS. Open-label treatment with citalopram in patients with irritable bowel syndrome: a pilot study. Prim Care Companion J Clin Psychiatry. 2005;7(4):162-6. PubMedCentral
5. Wise M. Citalopram-induced bruxism. Br J Psychiatry. 2001 Feb;178:182.