Sexual dysfunction MAOIs

The common side effects of MAOis include dizziness from orthostatic hypotension, drowsiness, insomnia, palpitations, rapid pulse, and sexual dysfunction. In addition, phenelzine appears to cause weight gain and fluid retention. 

Although the MAOIs can have serious and potentially life-threatening adverse effects, it is the more common and less dramatic side effects that often lead to the discontinuation of MAOIs. These side effects include orthostatic hypotension, drowsiness, insomnia, edema, weight gain, sexual dysfunction, and precipitation of mania. Rare side effects include hepatitis and leukopenia. Parasthesias may develop secondary to a MAOI-induced pyridoxine deficiency, which responds to oral pyridoxine supplementation. Overall, phenelzine appears to be more sedating, whereas trancylpromine is more activating because of its stimulant-like properties. Meclobomide has more excitatory side effects, such as restlessness and insomnia. 

The following side effects apply to the irreversible, nonselective MAOI antidepressants (phenelzine and tranylcypromine). The most common side effects are orthostatic hypotension, headache, insomnia, weight gain, sexual dysfunction, peripheral edema, and afternoon somnolence. Although MAOIs do not have significant affinity for muscarinic receptors, anticholinergic-like side effects are present at the beginning of treatment. Dry mouth is common but not as marked as in TCA therapy. Fortunately, the more serious side effects, such as hypertensive crisis and serotonin syndrome, are not common. 

MAOIs are commonly associated with treatment-emergent sexual dysfunction, including decreased libido, delayed ejaculation, anor-gasmia, and impotence. Some patients become tolerant to this side effect over time, but more often the problem persists unless the dose is reduced or another medication is used to counter the sexual side effects. The treatment of sexual side effects is discussed in the Selective Serotonin Reuptake Inhibitors section earlier in this chapter. 

MAOIs frequently are not the first choice when an antidepressant is needed. This is because their side effects include sedation, dizziness, insomnia, sexual dysfunction, rapid heartbeat, constipation, and agitation. Severe sudden elevation of blood pressure, especially when the patient eats aged meats and cheeses, or takes some over-the-counter cold medications, poses a serious threat of a stroke or other symptoms including headache, vomiting, and palpitations. 

The monoamine oxidase inhibitors are associated with a number of undesirable side effects including weight gain, postural hypotension, sexual dysfunction, and insomnia. The most serious side effect is the risk of tyramine-re-lated hypertensive crisis, often referred to as the "cheese effect," which can be fatal. To avoid this situation patients taking MAOIs must limit their tyramine intake, and the restrictive diet required to accomplish this leads to low patient compliance. A similar interaction occurs when switching patients from MAOI to SSRI therapy, and a minimum 2-week washout period before commencement of SSRI therapy is essential to allow MAO levels to return to normal. The therapeutic effects of the TCAs derive from their inhibition of serotonin and norepinephrine uptake, al-... 

In 1987, the United States Food and Dmg Administration (FDA) approved the use of fluoxetine for the treatment of depression and this derivative is now considered to be the prototype of a dmg class called selective serotonin reuptake inhibitors (SSRIs). As the name suggests, this term refers to the reuptake blockage of serotonin into the pre-synaptic membrane in order to indirectly increase neurotransmitter availability. A number of these derivatives showed beneficial effects for the treatment of a variety of additional conditions such as obsessive-compulsive disorders (OCD), bulimia nervosa, anxiety disorders, obesity, anorexia, post-traumatic stress disorders (PTSD) and others. SSRIs have become the first-line therapy for depression, which is based on improved side effect profiles when compared with TCA derivatives or MAOIs. A number of adverse effects are described in the pharmacological literature and include sexual dysfunction. 

---