Go on, admit it! How often do you take a detailed sexual history on
your elderly depressives? While as geropsychiatrists we espouse a
disdain for “ageism,” most of us probably pay too little attention to
sexuality in our older patients. Despite significant methodological
problems, studies have indicated that sexuality is an essential
component of quality of life and sexual activity remains relatively
stable throughout life until the age of 70. Approximately 60% of
married couples between 60-74 and 25% of those over 75 are still sexually active (Oppenheimer, 1991). Conversely, sexual dysfunction
does increase with age. In males, the percentage experiencing
minimal to severe erectile dysfunction increases from 39% at 40 years
to 67% at 70 years. Certain medical conditions (e.g. hypertension,
diabetes, heart disease) and their treatments (e.g. vasodilators,
antihypertensives, hypoglycemics) are frequently associated with this
condition (Feldman et al., 1994).
In the last few years it has become increasingly recognized that
antidepressants, especially the SSRIs, are among the drug classes that
are most often associated with sexual dysfunction (Rosen et al., 1999).
In young subjects the incidence of antidepressant-induced anorgasmia
has been estimated at 20-30% for paroxetine, 20-67% for sertraline,
and 20-75% for fluoxetine (Segraves, 1998). The SSRIs also are
frequently associated with erectile dysfunction, delayed ejaculation,
and inability to ejaculate. Proposed mechanisms for SSRI-induced
sexual dysfunction have included their effects on specific serotonin
sub-receptors and modulating effects on dopamine, prolactin, and
nitric oxide pathways (Rosen et al., 1999).
It has frequently been noted that the incidence of SSRI-induced sexual
dysfunction is underestimated. Studies that systematically inquire
about sexual dysfunction note significantly higher rates than those
that do not. In other words, “if you don’t ask, you don’t know!” This
may be an even bigger issue with elderly subjects, who might be less
likely than younger cohorts to spontaneously complain about sexual
dysfunction. In fact, the rates of any type of sexual dysfunction are
rarely reported in randomized, controlled trials (RCTs) in elderly
depressives (Menting et al., 1996). I could find only two RCTs that
reported on sexual dysfunction. Cohn et al. (1990) noted an 8.6%
incidence of male sexual dysfunction in a large, double-blind study
comparing sertraline with amitriptyline. In a randomized, placebo-controlled
trial of fluoxetine in 671 elderly depressives, impotence was
noted in 1.2% of fluoxetine-treated patients (Tollefson et al., 1995).
Given that these figures are underestimates of the true incidence of
SSRI-induced sexual dysfunction in the elderly, clinicians must begin
to address this issue, which may lead to non-compliance.
There have been many strategies proposed to treat SSRI-induced
sexual dysfunction, including waiting for tolerance to develop, lowering
the dose of the SSRI, switching antidepressants, using drug
holidays, and a variety of augmentation strategies. Certain antidepressants are reported to cause low incidence of sexual dysfunction,
including bupropion, nefazodone and mirtazapine. Augmentation
strategies include dopamine agonists (e.g. psychostimulants,
amantadine), alpha 2 adrenergic receptor antagonists (e.g. yohimbine),
antiserotonergic agents (e.g. cyproheptadine), and augmentation with
buspirone and ginkgo biloba.
Of all augmentation strategies, however, sildenafil (Viagra) has
received the most attention lately. Sildenafil is a selective inhibitor of
cyclic guanosine monophosphate-specific phosphodiesterase type 5,
and may restore erectile response to sexual stimuli via effects on nitric
oxide in the smooth muscle of the corpus cavernosum. In a pivotal
large, double-blind, placebo-controlled study, sildenafil was effective
for achieving and maintaining erection in several hundred men, which
included many elderly patients. Sildenafil was well-tolerated, with
headache, flushing, and GI upset being the most common adverse
effects (Goldstein et al., 1998). Though efficacy is still questionable,
sildenafil has also been studied for the treatment of sexual dysfunction
in women (Kaplan et al., 1999). Sildenafil is taken one hour prior to
sexual activity, starting with 50 mg and increasing to 100 mg if
necessary. While it appears well-tolerated and safe in elderly patients,
caution is essential in patients with cardiovascular disease. Sildenafil
causes system arterial and venous vasodilation and lowers blood
pressure by 8/5 mmHg, which does not appear to be dose related. It
should, therefore, not be used by patients on any form of nitrate therapy,
or by patients with active myocardial ischemia who would be
likely to receive nitrates (Heart and Stroke Foundation of Canada,
Canadian Cardiovascular Society, 1999). Drug interactions with
ketaconozole, erythromycin and cimetidine have been noted.
There are a small number of case reports and case series which have
described the use of sildenafil for SSRI-induced sexual dysfunction in
about two dozen young to middle-aged men and women (Ashton,
1999; Ashton et al., 1999; Nurnberg et al., 1999; Rosenberg, 1999;
Schaller et al., 1999; Fava et al., 1998). These reports suggest high rates
of effectiveness with excellent tolerability at doses of 50-100 mg.
While I could find no reports of its use in elderly patients with SSRI-induced
sexual dysfunction, I have recently treated two such patients
with sildenafil. One patient was a 70-year-old married man with major
depression, treated successfully with sertraline 50 mg for two years.
He was medically well and on no other medications. He noted
difficulties with sexual dysfunction (both decreased libido and erectile
dysfunction) immediately following initiation of sertraline treatment.
While he frequently commented about the problem, he was reluctant
to change the sertraline because of its significant benefits. Shortly
after sildenafil was released, however, he requested a small prescrip-tion,
“just to give it a try!” He experienced a dramatic improvement in
libido with a successful erection for the first time in two years, but did
not request a second prescription because his wife did not appear as
pleased with the drug’s effectiveness as he did.
The second patient was 72 years old, with long-standing, severe
Parkinson’s disease treated with l-dopa and pergolide. He also
experienced a number of bouts of recurrent depression and had
recently responded to sertraline 50 mg p.o. Associated with
improvement in depressive symptoms, however, was a reduction in
libido and significant difficulties initiating and maintaining an
erection. Libido improved with 50 mg of sildenafil, but 100 mg was
required in order for him to achieve a satisfactory erection. While
I was somewhat shocked when he told me the cost for 20 tablets
was $265, he thought this was a small price to pay for the
benefits received.
Adding another medication to treat the side effects of an SSRI is not
optimal for geriatric pharmacotherapy, regardless of the agent’s
safety and efficacy. There are times, however, when such treatment
may be necessary. Given that we will begin to see increasing
numbers of elderly patients treated with sildenafil for erectile dysfunction,
regardless of their exposure to SSRIs, it behooves us to
become familiar with this new class of agents. It should also
reinforce the need for all of us to carefully inquire about “.... one of
life’s most meaningful and pleasurable activities” (Butler, 1998).
Ashton, A.K. (1999). Sildenafil treatment of paroxetine-induced anorgasmia
in a woman. American Journal of Psychiatry, 156, 800.
Ashton, A.K., et al. (1999). Sildenafil treatment of serotonin reuptake
inhibitor-induced sexual dysfunction. Journal of Clinical Psychiatry, 60, 194-195.
Butler, R.N. (1998). The Viagra revolution. Geriatrics, 53, 8-9.
Cohn, C.K. et al. (1990). Double-blind multi-centre comparison of sertraline
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Fava, M. et al. (1998). An open trial of sildenafil in antidepressant-induced
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Feldman, H.A., et al. (1994). Impotence and its medical and psychological
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Goldstein, I. et al. (1998). Oral sildenafil in the treatment of erectile dysfunc-tion.
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(1999). A statement on the use of sildenafil in the management of sexual
dysfunction in patients with cardiovascular disease. Canadian Journal of
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Kaplan, S.A. et al. (1999). Safety and efficacy of sildenafil in postmenopausal
women with sexual dysfunction. Urology, 53, 481-486.
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Nurnberg, H.G. et al. (1999). Sildenafil for estrogenic serotonergic antide-pressant
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Oppenheimer, C. (1991). Sexuality in old age. In R. Jacoby & C. Oppenheimer (Eds.): Psychiatry in the Elderly. Oxford:
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review. Journal of Clinical Psychopharmacology, 19, 67-85.
Rosenberg, K.P. (1999). Sildenafil citrate for SSRI-induced sexual side
effects. American Journal of Psychiatry, 156, 157.
Schaller, J.L. et al. (1999). Sildenafil citrate for SSRI-induced sexual side
effects. American Journal of Psychiatry, 156, 156-157.
Segraves, R.T. (1998). Antidepressant-induced sexual dysfunction.
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Tollefson, G.D. et al. (1995). A double-blind, placebo-controlled clinical trial
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This article first appeared in Old Age Psychiatrist, the newsletter of the Faculty of Psychiatry of Old Age of the Royal College of Psychiatrists
(UK) and is expected to appear in the newsletter of the Canadian Association of Geriatric Psychiatry. It is reprinted here with the
permission of the author and the editor of Old Age Psychiatrist.
Nathan Herrmann MD FRCPC is Head of the Division of Geriatric Psychiatry, University of
Toronto Sunnybrook and Women’s College Health Sciences Centre (tel: +416.480.6133, fax:
+416.480.6022, e-mail Nathan.Herrmann@swchsc.on.ca).
