Some people can stop antidepressants without problems even after being on treatment for months. Others can have problems after being on treatment for as little as two weeks. Some can never stop. Drugs acting on the serotonin system, including SSRIs, SNRIs, most tricyclic antidepressants and others like mirtazapine appear more likely to cause withdrawal problems than antidepressants with no effect on serotonin systems.
Based on the effect of missing doses while on treatment, people will often know before starting to withdraw whether there is likely to be a problem – but fluoxetine’s long half-life may fool those taking it into thinking there is no problem.
There is no conclusive evidence that tapering helps but even if no problem is anticipated it is still better to reduce the dose by a maximum of 25% every week initially. The interval can be extended if needed If based on experience problems seem likely, consider reducing by 10% of the dose per week or per month. If significant problems seem likely, reduce by 1 mg per week. For this, to work you almost have to switch to a liquid. Most antidepressants can be made up in liquid form if you insist. If intolerable symptoms occur, go back to the previously tolerated dose until symptoms resolve and plan for a more gradual taper or for substitute therapy. Dose reduction may hit a “shelf” where it becomes very difficult to drop further but after which reducing can become easier again. An alternate option is to switch to dosulepin, a weak serotonin reuptake inhibitor and to reduce this slowly over time.
We know less about antidepressant withdrawal than about opiate or alcohol withdrawal. Acute withdrawal problems can be suppressed by going back on the triggering drug or raising the dose. Protracted withdrawal problems do not respond as clearly to the original agent.
Initial Withdrawal Symptoms
Nausea, diarrhea, abdominal pains, sweating, headache, dizziness, cold and flu-like symptoms, anxiety, irritability, trouble sleeping, electric shock-like feelings, visual after images, sounds and light sensitivity, muscle aches and pains, chills, confusion, pounding heart (palpitations), sexual dysfunction, twitching or other unusual movements, depression, agitation, and suicidal ideation.
Protracted Withdrawal Symptoms
After the initial withdrawal features wear off, there may be enduring food intolerance, altered taste or smell sensations, cardiac disturbances, pain or burning or other stranger sensory sensations, stress intolerance, temperature dysregulation, anxiety, and depression, enduring sexual dysfunction.