Cialis (Tadalafil) Safety in Adults 65 and Older

Does the dose change at 65?

The label ties its dose adjustments to creatinine clearance, Child-Pugh liver class and CYP3A4 inhibitors; for CYP3A4 inducers such as rifampin it calls for no dose adjustment [1]. For ED as needed, the starting dose is 10 mg, moved to 20 mg or down to 5 mg by response and tolerability, never more than once a day [1]. Once-daily ED starts at 2.5 mg and may go to 5 mg; BPH and ED with BPH use 5 mg once daily at about the same time each day [1].

What age does change is exposure. In healthy men aged 65 or older, tadalafil AUC is about 25% higher than in younger men [1]. The half-life is 17.5 hours [1]. The label says once-daily dosing provides continuous plasma tadalafil levels and that physicians should consider this when evaluating interactions with nitrates, alpha-blockers, antihypertensives, potent CYP3A4 inhibitors or substantial alcohol [1].

Kidney function is the main dose driver

The label's renal rules are specific [1]:

• Creatinine clearance 30 to 50 mL/min, as needed: start 5 mg, maximum 10 mg and no more often than every 48 hours [1].
• Creatinine clearance below 30 mL/min or hemodialysis: maximum 5 mg and no more often than every 72 hours [1].
• Once-daily use at creatinine clearance below 30 mL/min: not recommended [1].
• BPH or ED with BPH at 30 to 50 mL/min: start 2.5 mg, and 5 mg may be considered [1].

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Nitrates remain the absolute rule

Any form of organic nitrate, taken regularly or intermittently, is contraindicated with Cialis [1]. The label's single timing allowance is for an emergency: where a nitrate is medically necessary in a life-threatening situation, at least 48 hours should pass after the last Cialis dose, and the nitrate should still be given only under close medical supervision with hemodynamic monitoring [1].

A 150-man crossover study looked at the time course: men took tadalafil 20 mg or placebo daily for 7 days, then sublingual nitroglycerin 0.4 mg at set times [3]. Standing systolic pressure fell below 85 mm Hg in more men on tadalafil at 4, 8 and 24 hours, with no significant difference from placebo at 48, 72 and 96 hours [3]. The 48-hour figure is an emergency threshold, not a routine spacing schedule. The label also says a man who develops anginal chest pain after taking Cialis should seek immediate medical attention [1].

Alpha-blockers and blood pressure drugs

Tadalafil and alpha-blockers are both vasodilators, the effect on blood pressure is additive, and symptomatic hypotension such as fainting can occur [1]. The label's pharmacology numbers show how much this varies by alpha-blocker:

• With doxazosin 8 mg daily, tadalafil 20 mg gave a placebo-subtracted maximal standing systolic fall of 9.8 mm Hg (3.6 mm Hg supine); in a second doxazosin study, 16 of 24 men on tadalafil had a systolic reading below 85 mm Hg or a fall over 30 mm Hg, against 6 on placebo [1].
• With tamsulosin 0.4 mg, the placebo-subtracted standing fall was 1.7 mm Hg with tadalafil 10 mg and 2.3 mm Hg with 20 mg, and tadalafil 5 mg daily plus tamsulosin produced no outliers [1].
• With alfuzosin 10 mg, the standing fall was 4.4 mm Hg with tadalafil 20 mg compared with placebo [1].

The label's rule for ED is to have the man stable on the alpha-blocker first and then start Cialis at the lowest dose [1]. For BPH, the Cialis label does not recommend combining Cialis with an alpha-blocker, because the efficacy of the combination has not been adequately studied and because of the risk of blood-pressure lowering [1]. The label also states that patients taking an alpha-blocker for BPH should stop it at least one day before starting once-daily Cialis for BPH [1].

With other antihypertensives (amlodipine, ARBs, bendroflumethiazide, enalapril, metoprolol), pharmacology studies found only small additional blood pressure reductions compared with placebo [1]. In healthy volunteers, tadalafil 20 mg lowered supine blood pressure by a mean maximal 1.6/0.8 mm Hg versus placebo [1]. Alcohol also matters: 5 units or more with Cialis can increase orthostatic signs and symptoms — higher heart rate, lower standing blood pressure, dizziness and headache [1].

Dizziness and falls

In the three 12-week BPH and ED/BPH studies, dizziness was reported by 1.0% of men taking tadalafil 5 mg once daily versus 0.5% on placebo [1]. Separately, the label notes that in the as-needed ED studies diarrhea was reported more frequently in men aged 65 and older who took Cialis [1].

Falls are common in this age group regardless of drug: 1 in 4 adults 65 and older reports falling each year, falls are the leading cause of injury-related death in this group, and the age-adjusted fall death rate rose from 64.7 per 100,000 in 2018 to 78.4 per 100,000 in 2024 [2]. The label does not report falls as an outcome. Its relevant warning is about vascular tone: patients with severely impaired autonomic control of blood pressure may be particularly sensitive to vasodilators, including PDE5 inhibitors [1].

Heart disease: who the trials excluded

Treatments for erectile dysfunction, including Cialis, should not be used in men for whom sexual activity is inadvisable because of cardiovascular status [1]. The label lists groups that were not included in the trials and for whom Cialis is therefore not recommended: myocardial infarction within 90 days, unstable angina or angina during intercourse, NYHA class 2 or greater heart failure within 6 months, uncontrolled arrhythmias, blood pressure below 90/50 mm Hg or uncontrolled hypertension, and stroke within 6 months [1]. Men with left ventricular outflow obstruction such as aortic stenosis can be sensitive to vasodilators [1].

Vision and hearing

Sudden vision loss in one or both eyes can be non-arteritic anterior ischemic optic neuropathy (NAION), reported rarely after marketing with all PDE5 inhibitors; based on published literature the label gives an annual incidence of 2.5 to 11.8 cases per 100,000 in men aged 50 and older [1]. Two observational case-crossover studies suggested roughly a 2-fold risk (estimates 2.15, 95% CI 1.06 to 4.34, and 2.27, 95% CI 0.99 to 5.20), and the label states that neither the reports nor these studies substantiate a causal relationship [1]. The label directs patients to stop Cialis and seek medical attention for sudden vision loss, and advises caution with prior NAION or a crowded optic disc; use is not recommended in hereditary retinal disorders such as retinitis pigmentosa [1]. Sudden hearing decrease or loss has also been reported, and the label says it cannot tell whether it is directly related to the drug [1].

Liver function

With mild or moderate impairment (Child-Pugh A or B), the as-needed dose should not exceed 10 mg once per day [1]. In severe impairment (Child-Pugh C), Cialis is not recommended [1].

What the trials show for older men

An integrated analysis of five 12-week trials enrolled 1,112 men with a mean age of 59 and a range of 22 to 82 [4]. With tadalafil 20 mg, the erectile function domain of the IIEF improved by a mean 7.9 points, 75% of intercourse attempts were successful, and 81% reported improved erections versus 35% on placebo (P<0.001) [4].

A pooled analysis of 11 trials covering 2,102 men (mean age 56) reported that tadalafil worked up to 36 hours after dosing and was effective in patients of all ages, with headache, dyspepsia, back pain and myalgia the most frequent adverse events [5]. Remember what 36 hours means: improved erectile function versus placebo, still requiring sexual stimulation, not a sustained erection [1]. A review found no convincing cardiovascular safety signal in PDE5 inhibitor trials, but its conclusion concerned men with satisfactory cardiac and physical status [6]. The Cialis label does not recommend use in the listed cardiovascular groups that were excluded from its trials [1].

Same drug, different product: Adcirca

Adcirca is a separately approved tadalafil 20 mg tablet for pulmonary arterial hypertension [7]. Adcirca and Cialis are different tadalafil products with different indications; both are available as 20 mg tablets [8][7]. The Cialis label says Cialis has not been studied in combination with other PDE5 inhibitors or other ED treatments [1].