Sexual Health, Lack of Libido

Postsynaptic Serotonin Antagonists, including nefazodone and mirtazapine, have minimal if any effect on sexual functioning. [12] These antidepressants are reasonable first-line agents for treating depression, and also have been shown to improve sexual side effects of SSRIs when used as antidotes.

Mirtazapine works as a potent 5-HT2 and 5-HT3 antagonist, and also has a2-antagonistic properties. Sexual side effects are believed to be mediated through 5-HT2 stimulation. Therefore, mirtazapine's antagonistic action should improve or resolve sexual side effects. Several case reports have described patients receiving mirtazapine while on SSRI therapy. [24] Sexual functioning returned to baseline or improved for all patients. Side effects include sedation, irritability, muscle soreness, stiffness, and weight gain.

Of interest, nefazadone has been shown to decrease the frequency of sexual obsessions as seen with nonparaphilic compulsive sexual behavior, but does not produce the undesired sexual side effects caused by SSRI treatment. [27] The term nonparaphilic compulsive sexual behavior defines the disorder in which an individual has intense sexually arousing fantasies, urge, and associated sexual behaviors that cause significant distress or impairment.

Sildenafil (Viagra, Pfizer, New York, NY) works as a competitive inhibitor of cGMP-specific phosphodiesterase (PDE) type 5. PDE5 inhibitors are associated with increased nitric oxide production, resulting in smooth muscle relaxation and increased blood flow to the genital tissues. Sildenafil is currently approved only for the treatment of male erectile dysfunction, but has been proven in many studies to reverse sexual side effects of SSRIs. [12] It is also proven effective in the treatment of female sexual dysfunction. [28, 29] Sildenafil can be taken as needed 30 to 60 minutes prior to sexual activity. The usual doses range from 50 to 100 mg.

The most obvious mechanism of action is the increase of blood flow to the clitoris and vagina. These positive effects on arousal and sensation can secondarily improve sexual motivation or libido. Common side effects are headaches, facial flushing, nasal congestion, and indigestion. The usual precautionary measures should be considered when using sildenafil, which includes the contraindication to using nitrates, including recreational use of amyl nitrate. Sildenafil and nitrates can cause a fatal drop in blood pressure.{mosbanner:id=1:right:0}

Eros-CTD or clitoral therapy device developed by UroMetrics, Inc. became the first treatment for female sexual dysfunction approved by the FDA in May 2000. [2] Eros-CTD is a small pump with a tiny plastic cup attachment that fits over the clitoris and surrounding tissue. It provides gentle suction in efforts to enhance arousal and to engorge the clitoris and labia by pulling blood into the area. Although no studies have yet been done on the effects of Eros-CTD on SSRI-induced sexual dysfunction, it may prove to be effective in the same way that sildenafil increases blood flow to genital tissues and thus reduces sexual side effects.

Switching Antidepressants: Several studies have shown that switching to an antidepressant associated with fewer sexual side effects may be an effective strategy for some patients. Some studies suggest that a switch to nefazodone, bupropion or mirtazapine improves sexual dysfunction, but does not decrease the antidepressant effects. [5,9,12] However, some studies have reported loss of antidepressant effects, plus new side effects.

In one study, patients on fluoxetine treatment with sexual dysfunction were switched to bupropion. 64% reported a much improved sexual functioning; however, 36% of the patients discontinued bupropion because they did not get an antidepressant effect and they developed new side effects, such as agitation. [30] Another study involved switching patients on sertraline, an SSRI, to either nefazodone or back to sertraline. [31] Patients went through a one-week washout period (no medication), then were randomly assigned to double-blind treatment with either nefazodone or sertraline.

In terms of discontinuation rates with nefazodone and sertraline respectively, 12% and 26% discontinued because of adverse effects and 10% and 3% discontinued because of lack of antidepressant effects. Twenty-six percent of the nefazadone-treated patients had a reemergence of sexual dysfunction, compared to 76% in the sertraline-treated group, which is statistically significant.

Regarding mirtazapine, a study was conducted in which 19 patients (12 women and 7 men) with SSRI-induced sexual dysfunction were switched to mirtazapine. [32] 58% of patients had a return of normal sexual functioning, and 11% reported significant improvement in sexual functioning. All patients maintained their antidepressant response. From the initial group of 21 patients that met criteria, two men dropped out of the study, complaining of tiredness due to mirtazapine.

If a patient seems to only respond to SSRI treatment for antidepressant effects, some case reports have shown that fluvoxamine causes fewer sexual side effects. [33] In three case reports, women who switched to fluvoxamine reported resolution or decrease in sexual dysfunction, while still maintaining the antidepressant benefits of SSRI treatment. However as mentioned previously, a multicenter study of 1,022 outpatients showed that fluvoxamine caused a high incidence (62.3%) of sexual dysfunction. [9] (table 4) If a patient requires a SSRI for her depression, a trial of fluvoxamine seems reasonable.

Initial Antidepressant Selection: When first treating a patient for depression, perhaps starting with an antidepressant shown to cause fewer sexual side effects is a beneficial strategy. As mentioned in the previous section, nefazodone, buspropion, and mirtazapine are associated with less sexual dysfunction. In a prospective multicenter study of 1,022 outpatients, the incidence of sexual dysfunction with SSRIs and venlafaxine is high, ranging from 58% to 73%, as compared with nefazodone and mirtazapine, ranging from 8% to 24.4%. [9]

Conclusion: Female sexual dysfunction is a common problem, with depression and its treatment being significant contributing or causal factors. When first meeting a patient complaining of depressive symptoms, it is necessary to obtain a full medical history, including a sexual history. Not only is a sexual history significant for knowing and treating the patient as a whole, but also it will allow a health care provider to ascertain whether sexual dysfunction was present before antidepressant treatment or was caused directly by the medication.

When initially placing a patient on an antidepressant, one should consider prescribing a medication shown to produce fewer sexual side effects, such as nefazodone, buspropion, and mirtazapine. If a patient is already taking a SSRI and complaining of sexual side effects, discuss with the patient the numerous strategies. If waiting seems to be a valid option and they have just begun their treatment recently, see if side effects abate after a couple months. The next logical step would be implementing a lower dosage or taking a drug holiday because adding another medication or changing medications will often entail more or different side effects, and possibly lessen antidepressant effectiveness. After reviewing the literature, this order of implementing strategies seems to be the most beneficial; however, most importantly, treatment must be individualized. Issues to consider are the patient's desires, underlying medical problems, antidepressant effects of various medications, and whether the sexual side effects are perceived as causing personal distress.

Sexual health is an extremely important part of a person's life, affecting one's self-esteem, relationships, and sense of well being, and sexual function complaints must be addressed and taken seriously.