Viagra, Sildenafil, and Mental Health: What the Clinical Evidence Actually Shows

Does sildenafil treat depression or anxiety?

No. Viagra (sildenafil citrate 25, 50 and 100 mg tablets) was approved on 27 March 1998 for erectile dysfunction, and that remains its only indication [1]. Revatio is a sildenafil product for pulmonary arterial hypertension, and its FDA record lists 20 mg tablets [3]. Neither product is approved for a psychiatric condition [1][3].

What the Viagra label says about mood

The label's adverse reactions section lists events reported in fewer than 2% of patients in controlled trials, where a causal relationship to Viagra is uncertain. That list includes depression, insomnia, somnolence and abnormal dreams [2]. It records what was reported; it does not state that sildenafil causes or lifts depression.

The reactions seen at 2% or more are headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness and rash [2].

What the pivotal trials measured

Goldstein and colleagues published two sequential double-blind studies in the New England Journal of Medicine in 1998: a 24-week dose-response study in 532 men given 25, 50 or 100 mg or placebo, and a separate 12-week flexible-dose study in 329 men escalated to 100 mg [4].

The published trials reported erectile-function scores, intercourse logs, and a global-efficacy question as efficacy measures [4]. In the flexible-dose study, 69% of intercourse attempts were successful on sildenafil versus 22% on placebo [4].

What patients notice

At 100 mg, the fixed-dose trials reported headache in 28% versus 7% on placebo, flushing 18% versus 2%, dyspepsia 17% versus 2%, abnormal vision 11% versus 1%, and nasal congestion 9% versus 2% [2]. Visual changes were mostly a color tinge, light sensitivity or blurred vision, mild to moderate and transient [2]. Sildenafil is about 10-fold more potent on PDE5 than on PDE6 in the retina, which is thought to explain those color effects [2]. Discontinuation for adverse reactions was 2.5% versus 2.3% on placebo [2].

Does it act without sexual stimulation?

No. The label describes sildenafil as enhancing the nitric oxide/cGMP signal released during sexual stimulation and states it has no effect in the absence of sexual stimulation [2]. Dosing is as needed, about an hour before sexual activity, up to 100 mg and no more than once a day [2]. HealthRX.com offers sildenafil by prescription.

Antidepressants and other drugs

The label's drug interactions section covers nitrates, which are contraindicated, alpha-blockers, amlodipine, ritonavir and other CYP3A4 inhibitors, and alcohol [2]. Ritonavir raised sildenafil exposure 11-fold and caps the dose at 25 mg in 48 hours; erythromycin or strong CYP3A4 inhibitors such as ketoconazole, itraconazole, or saquinavir call for a 25 mg starting dose [2]. No individual antidepressant is named in that section [2].

The short answer

Sildenafil treats erectile dysfunction and carries no psychiatric indication [1][2].