Finasteride Geriatric (65+) Caregiver Administration Guidance

Which finasteride is he taking?

Two strengths of oral finasteride are sold in the United States, and they are approved for different things.

Proscar, 5 mg, was approved on June 19, 1992 for symptomatic BPH in men with an enlarged prostate: to improve symptoms, to reduce the risk of acute urinary retention, and to reduce the risk of surgery including transurethral resection of the prostate and prostatectomy. Given with the alpha-blocker doxazosin, it is also approved to reduce the risk of symptomatic progression of BPH. It is not approved to prevent prostate cancer [3][1].

Propecia, 1 mg, was approved on December 19, 1997 for male pattern hair loss. It is for men only, is not indicated for women, and its efficacy in bitemporal recession has not been established [4][2]. The trials behind that approval enrolled men aged 18 to 41 [2][5].

Only oral tablets are FDA-approved. There is no approved topical or injectable finasteride, and generic tablets carry the same labeled risks as the brand [2].

How the tablet is given

The Proscar label describes one 5 mg tablet once a day, with or without meals [1]. The Propecia label describes one 1 mg tablet once daily, with or without meals, and notes that daily use for three months or more is usually needed before benefit appears, that continued use sustains the benefit, and that stopping reverses the effect within 12 months [2].

Handling rules for caregivers

The Proscar label says females who are pregnant or may potentially be pregnant should not handle crushed or broken tablets, because of the possibility of absorption of finasteride and the potential risk to a male fetus. It says the tablets are coated and prevent contact with the active ingredient during normal handling, provided they have not been broken or crushed. If a pregnant female comes into contact with a crushed or broken tablet, the label says the contact area should be washed immediately with soap and water [1].

Pregnancy is a contraindication on both labels, and the 1 mg label lists Pregnancy Category X [1][2]. The label cites animal data behind the warning: in rats given finasteride during major organogenesis, hypospadias occurred in 3.6 to 100 percent of male offspring at maternal doses roughly 0.1 to 86 times the human 5 mg dose [1].

Disposing of unused tablets

FDA says the best way to dispose of most unused or expired medicines is a drug take-back location or a mail-back envelope, and that medicines should not be flushed unless they appear on the FDA flush list. Finasteride does not appear among the medicines on that list [6].

What the label says about PSA

The Proscar label says it reduces serum PSA by approximately 50 percent within six months of treatment, that a new PSA baseline should be established at least six months after starting, and that PSA should be monitored periodically afterward. It says any confirmed increase from the lowest PSA value while on treatment may signal prostate cancer and should be evaluated even if the number is still within the normal range for men not taking a 5-alpha reductase inhibitor. For an isolated PSA value after six months or more of treatment, the label says values should be doubled for comparison with normal ranges in untreated men. Percent free PSA is unchanged [1].

With the 1 mg tablet, mean PSA in men aged 18 to 41 fell from 0.7 ng/mL at baseline to 0.5 ng/mL at month 12 [2].

Breast changes and high-grade prostate cancer

Male breast cancer appears in the labels as a postmarketing report, with the relationship to long-term finasteride use stated as unknown [2][1]. In the 4-year PLESS trial of 5 mg, breast enlargement was reported in 0.5 percent vs 0.1 percent on placebo in year 1 and 1.8 percent vs 1.1 percent in years 2 to 4; breast tenderness was 0.4 percent vs 0.1 percent in year 1 [1]. MTOPS recorded four cases of breast cancer in men taking finasteride and none in men not taking it, while PLESS recorded two cases, both on placebo, and the 7-year Prostate Cancer Prevention Trial recorded one case on each treatment [1].

High-grade prostate cancer is a separate label warning. In the Prostate Cancer Prevention Trial, 18,882 men aged 55 or older took finasteride 5 mg or placebo for seven years; Gleason score 8 to 10 cancer was found in 1.8 percent on finasteride vs 1.1 percent on placebo. The labels state that 5-alpha reductase inhibitors may increase the risk of high-grade prostate cancer, and the Propecia label says the clinical significance for men taking 1 mg is unknown [1][2][7].

Sexual side effects in older men

In PLESS, which followed 1,524 men on 5 mg and 1,516 on placebo, aged 45 to 78, for four years, year-1 rates were impotence 8.1 percent vs 3.7 percent, decreased libido 6.4 percent vs 3.4 percent, decreased ejaculate volume 3.7 percent vs 0.8 percent, and ejaculation disorder 0.8 percent vs 0.1 percent. In years 2 to 4 there was no significant difference between groups for impotence, decreased libido or ejaculation disorder. Discontinuation for sexual adverse reactions was 3.7 percent vs 2.1 percent [1].

With 1 mg, three 12-month trials in 945 men on drug and 934 on placebo found decreased libido 1.8 percent vs 1.3 percent, erectile dysfunction 1.3 percent vs 0.7 percent, and ejaculation disorder 1.2 percent vs 0.7 percent; 3.8 percent vs 2.1 percent reported one or more of these (p=0.04). The label says resolution occurred in men who discontinued because of these effects and in most of those who continued [2].

The Propecia label also lists, as postmarketing reports, sexual dysfunction that continued after stopping (erectile dysfunction, libido disorders, ejaculation disorders and orgasm disorders) and male infertility and poor seminal quality, with normalization or improvement reported after discontinuation [2]. The Proscar label says persistent events were reported rarely in men taking 5 mg for BPH, that most of those men were older and on other medicines, and that the independent role of Proscar is unknown [1].

Mood, memory and the older patient

The Propecia label lists depression, suicidal ideation and behavior in its postmarketing section, and states that these reports are voluntary and from a population of uncertain size, so a causal relationship cannot reliably be established [2]. FDA's August 2022 labeling supplement changed the wording from depression to depression, suicidal ideation and behavior [8]. Neither label carries a boxed warning for these effects [2].

Two large cohorts of mostly older BPH patients give a mixed picture. A study of 93,197 Ontario men aged 66 or older starting a 5-alpha reductase inhibitor, mostly for BPH, found no increase in suicide (hazard ratio 0.88, 95 percent CI 0.53 to 1.45), a higher risk of self-harm limited to the first 18 months (HR 1.88, CI 1.34 to 2.64), and elevated depression risk (HR 1.94 in the first 18 months, 1.22 afterward), equal to about 17 additional self-harm and 237 additional depression cases per 100,000 patient-years [9]. A Swedish register study of 2,236,876 men aged 50 to 90, including 70,645 finasteride starters with a median age of 73, found depression HR 1.61 (CI 1.48 to 1.75) and no significant suicide association (HR 1.22, CI 0.99 to 1.49). Its dementia association faded over time, which the authors said may partly reflect more dementia detection in men with BPH [10].

A one-year randomized trial of 60 hypogonadal men aged 60 or older, in which finasteride 5 mg or placebo was paired with testosterone or vehicle, found that finasteride produced a small increase in performance on the Benton Judgment of Line Orientation test and no major cognitive improvements [11].

Falls, dizziness and alpha-blockers

When finasteride is combined with an alpha-blocker, the Proscar label's trial data show more orthostatic symptoms. In MTOPS, 3,047 men with symptomatic BPH were randomized to finasteride 5 mg (n=768), doxazosin (n=756), the combination (n=786) or placebo (n=737) for four to six years. Drug-related postural hypotension was reported in 8.0 percent on placebo, 9.1 percent on finasteride alone, 16.7 percent on doxazosin alone and 17.8 percent on the combination; dizziness was 8.1, 7.4, 17.7 and 23.2 percent respectively. The label lists postural hypotension and dizziness among the effects more frequent with the combination than with either drug alone, and says combination therapy was associated with no new clinical adverse experience [1].

A chart review of 117 patients over 75 in a geriatric center found that 71.8 percent had at least one potentially inappropriate urologic prescription, 91.7 percent of those involving alpha-blockers, and that this group had higher odds of a history of falls (odds ratio 3.22, 95 percent CI 1.08 to 10.2) [12].

The Proscar label reports no clinically significant adverse interactions when finasteride was used in clinical studies with alpha-blockers, ACE inhibitors, beta blockers, calcium channel blockers, diuretics and other common medicines [1].