Citalopram
Class: Antidepressant – SSRI (Selective Serotonin Re-uptake Inhibitor)
Indications: depression, anxiety (chronic)
Contraindications/cautions: hepatic impairment, epilepsy, bleeding disorders, abrupt withdrawal; caution in QT prolongation – sertraline may be an alternative
Adverse reactions: common: nausea, sweating, tremor, diarrhoea (excessive serotonin), constipation, somnolence, insomnia, dizziness, headache, dry mouth; agitation, anxiety; tinnitus; less common: cough, postural hypotension, tachycardia, amnesia, taste disturbance, visual disturbances, pruritus, hyponatraemia, sexual dysfunction, QT prolongation
Metabolism/clearance: metabolised hepatically by CYP2C19, CYP2D6 & CYP3A4 – caution when used with drugs that inhibit CYP
Hepatic impairment – max daily dose 20 mg
Renal impairment – no information for use if eGFR < 20 mL/min/1.73m2
Interactions:
- additive risk of serotonin syndrome (potentially fatal syndrome – symptoms include sweating, diarrhoea, confusion) with other serotonergic drugs e.g. amitriptyline, carbamazepine, fluoxetine, paroxetine, tramadol, lithium
- increased risk of bleeding (antiplatelet effect) with anticoagulants
| Dosing: | |
|---|---|
| oral: | 10 to 40 mg once a day Adult 20 mg once daily, increased if necessary in steps of 10 mg daily at intervals of 2 to 3 weeks; maximum 40 mg daily; elderly 10 mg once daily, increased if necessary after 2 to 3 weeks to a maximum of 20 mg daily Note: The daily dose of citalopram should not exceed 40 mg daily as doses above this are associated with an increased risk of QT-interval prolongation |
| subcut/rectal: | not available |
| Syringe driver: | not available |
Mechanism of action: SSRIs selectively inhibit the re-uptake of serotonin (5-hydroxytryptamine, 5-HT) in the pre-synapse, increasing the available serotonin in the brain
Onset: depression: 2 to 4 weeks anxiety or pain: 3 to 7 days
Peak response: 5 to 6 weeks
Notes:
- escitalopram is available. Doses used are approximately half
- doses of greater than 40 mg per day have been associated with QT interval prolongation
- may be useful in pruritis due to primary biliary cholangitis