Adverse events
A large study of 2102 men from 11 different multicentered, randomized, double-blind, placebo controlled trials of tadalafil reported the drug is well tolerated overall. Fifty-one percent of men using tadalafil 20 mg had at least one adverse event (AE), but only 3.2% discontinued treatment. The most common AEs reported with the 20 mg dose were headache (15%), dyspepsia (8%), and back pain (5%) (Table 1). Most AEs are a result of vasodilation of vascular beds other than in the penis.
Table 1. Most common tadalafil treatment-emergent adverse events.
Safety variable | Placebo (n = 638) | Tadalafil 10 mg (n = 321) | Tadalafil 20 mg (n = 1143) |
---|---|---|---|
Subjects with ≥1 treatment emergent AE | 247 (39%) | 185 (58%) | 577 (51%) |
Discontinuation for AE | 8 (1.3%) | 5 (1.6%) | 36 (3.2%) |
Most common treatment emergent AEs | |||
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30 (5%) | 38 (12%) | 173 (15%) |
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7 (1%) | 23 (7%) | 90 (8%) |
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15 (2%) | 20 (6%) | 60 (5%) |
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24 (4%) | 26 (8%) | 23 (2%) |
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6 (1%) | 16 (5%) | 33 (3%) |
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8 (1%) | 10 (3%) | 39 (3%) |
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4 (1%) | 11 (3%) | 28 (2%) |
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5 (1%) | 10 (3%) | 31 (3%) |
Although frequently asked about by patients, priapism is rarely associated with PDE5 inhibitors. Several case reports have found an extraordinarily uncommon link between sildenafil and priapism, and only a single case report exists in the literature implicating tadalafil with priapism. PDE5 inhibitors including tadalafil may actually have some benefit in preventing recurrent, or stuttering, priapism. A small series of 4 men with stuttering priapism were administered daily PDE5 inhibitors, one case of which used tadalafil, and all four men had decreases in priapism recurrences.