OVERVIEW ã…¡ Patients will ask how to manage itching from chronic kidney disease. This chronic "uremic pruritus" affects about 40% of patients on dialysis and can lead to depression and poor sleep. Patients may have localized or widespread itching, possibly related to the effects of kidney disease on nerves, inflammation, and dry skin.
Tell patients to use a fragrance-free moisturizer 2 to 4 times per day. Explain that it may take 2 weeks to work. Suggest adding a topical anesthetic, such as pramoxine (CeraVe Itch Relief, etc) or capsaicin, for localized itching if needed.
MANAGEMENT
For severe itching or when topical therapies aren't enough, suggest gabapentin 100 mg after each dialysis session and titrating if needed. Gabapentin (Gaptin) and pregabalin (Lyrica) have been the most studied of the oral treatment options in CKD-associated itching. The proposed mechanism is believed to be blockage of neuronal calcium influx, which may prevent the itching sensation. The most common doses studied range from 100 to 300 mg (gabapentin) and 25 to 75 mg (pregabalin), given after each dialysis session. Lower doses are used in order to minimize adverse effects (e.g., dizziness, drowsiness, fatigue). Recommend starting with gabapentin 100 mg given after each dialysis session. Explain that some patients who don't tolerate gabapentin may have success with pregabalin. But both can cause dizziness and sedation.
Cholestyramine. May help reduce itching by binding uremic toxins in the GI tract to prevent their absorption. The most common adverse effect associated with cholestyramine in these studies was constipation.
Antihistamines. Lean away from an antihistamine (diphenhydramine, etc) in most cases. Any perceived benefit is likely due to their sedating effects. Antihistamines are sometimes tried to relieve itching. Histamine receptor antagonists (e.g., cetirizine, diphenhydramine, hydroxyzine, loratadine) are usually not effective and may be associated with adverse effects such as sedation.
And don't rely on phosphate binders or a low-phosphorus diet to relieve itching. Elevated phosphorus levels have been associated with pruritus, but lowering them doesn't seem to help. Caution against using rubbing alcohol, hand sanitizers, etc. These may be cooling, but the alcohol can dry the skin and worsen itching.
REFERENCES
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Simonsen, E., Komenda, P., Lerner, B., Askin, N., Bohm, C., Shaw, J., Tangri, N. and Rigatto, C. (2017). Treatment of Uremic Pruritus: A Systematic Review. American Journal of Kidney Diseases, [online] 70(5), pp.638–655. Available at: https://www.ajkd.org/article/S0272-6386(17)30781-3/abstract
Mettang, T. and Kremer, A.E. (2015). Uremic pruritus. Kidney International, [online] 87(4), pp.685–691. Available at: https://www.kidney-international.org/article/S0085-2538(15)30196-4/pdf