Inclusion criteria:
Age older than 18 years
Hemodialysis for at least 3 months and having itch despite the adequacy of hemodialysis (Kt/V > 1.2)
5D-itch score more than 5
PSQI score equal and above 5
Exclusion criteria:
Anemia ( Hemoglobin less than 7 g/dL)
Hyperparathyroidism ( iPTH > 600 )
Phosphorus level higher than 6 mg/dL and calcium higher than 10.5 mg/dL, or calcium multiplied by phosphorus higher than 60
Chronic skin diseases with itching which not related to uremia caused by kidney failure, such as psoriasis, dermatitis, and lichen planus.
Chronic liver failure or high bilirubin level (1.5 times higher than the upper limit of normal) , and ALT, AST more than 5 times higher than the upper limit of normal.
Untreated hypothyroidism
Patients with psychiatric disorders, such as bipolar disorder, mental retardation, cognitive-functional disorder, or use of any psychotropic medication during the past month.
History of suicide or patients with suicidal ideation
Inability to receive oral medication
Use of corticosteroids and opium
Pregnancy and lactation
History of allergy to mirtazapine
Receiving medications that used for sleep disorders treatment within 1 month before entering the study (such as tricyclic antidepressants, atypical antidepressants, benzodiazepines, antihistamines, anticholinergics, and barbiturates)
No interest to participate in the study or continue to treatment
Any complications leading to intolerance and discontinuation of treatment with studied drugs