Table 6. Causes of DRPs in patients with BPH (n = 295).

Code	Causes	Number of causes (Percentage, %)
C1	Drug/Dose selection	248 (84.1)
C1.1	Inappropriate drug selection	128 (43.4)
C1.2	Inappropriate dosage selection	52 (17.6)
C1.4	Pharmacokinetic problems, including ageing/deterioration in organ function and interactions	1 (0.3)
C1.5	Synergistic/preventive drug required and not given	35 (11.9)
C1.7	New symptom or indication revealed/presented	4 (1.4)
C1.8	Manifest side effect, no other cause	28 (9.5)
C2	Drug use process	28 (9.5)
C2.1	Inappropriate timing of administration and/or dosing intervals	6 (2.0)
C2.2	Drug underused/under-administered	17 (5.8)
C2.3	Drug overused/over-administered	3 (1.0)
C2.5	Drug abused (unregulated overuse)	1 (0.3)
C2.6	Patient unable to use drug/form as directed	1 (0.3)
C3	Information	1 (0.3)
C3.1	Instruction for use/taking not known	1 (0.3)
C4	Patient/Psychological	9 (3.1)
C4.1	Patient forgets to use/take drug	2 (0.7)
C4.3	Patient suspects side effect	1 (0.3)
C4.5	Patient unwilling to bother physician	2 (0.7)
C4.7	Patient unwilling to adapt life-style	2 (0.7)
C4.8	Burden of therapy	1 (0.3)
C4.10	Patient takes food that interacts with drugs	1 (0.3)
C5	Logistics	5 (1.7)
C5.2	Prescribing error (only in case of slip of the pen)	5 (1.7)
C6	Other	4 (1.4)
C6.2	No obvious cause	4 (1.4)

Note: Only causes with the frequency of more than one were included.