Starting dose can be 10 mg of citalopram, fluoxetine or paroxetine.After a week, if the patient tolerates the medication, the dose can be increased.
SSRIs can often be started with a 20 mg daily dose (for citalopram, fluoxetine and paroxetine) with no further dose increases. When using TCAs, start with a low dose and increase slowly e.g.
For most indications the SSRIs are considered first-line as they are better tolerated and have a wider safety margin than the tricyclic antidepressants (TCAs) and irreversible nonselective monoamine oxidase inhibitors (MAOIs).
MAOIs (phenelzine, tranylcypromine) are now rarely used because of their severe, and potentially fatal, interactions with some foods and medications.
The most important interactions are those with other drugs that affect serotonergic neurotransmission as these can lead to serotonin toxicity and, in severe cases, serotonin syndrome Features of serotonin toxicity (see Table 4) may be relatively mild, such as tremor and low grade restlessness. Serotonin syndrome is the most severe form of serotonin toxicity characterised by a recognised cluster of prominent and severe clinical features that usually require supportive management and stopping the causative agent(s).
If severe, refer immediately to an emergency department A number of drugs and herbal products (principally St John’s Wort) have serotonergic activity and can cause serotonin toxicity or the syndrome if given alone, especially in high doses.